Film / Back to the Future

He was never in time for his classes... he wasn't in time for his dinner... then one day... he wasn't in his time at all.

Marty McFly: Wait a minute, wait a minute, Doc... are you telling me you built a time machine... out of a DeLorean?!
Dr. Emmett "Doc" Brown: The way I see it, if you're gonna build a time machine into a car, why not do it with some style?

The first film of the Back to the Future trilogy released in 1985, starting the Back to the Future franchise. It was directed by Robert Zemeckis, with the screenplay by Zemeckis and Bob Gale.

Marty McFly, a teenager from 1985, accidentally sends himself to 1955 in the time machine his friend Doc Brown built out of a DeLorean, and requires 1.21 gigawatts of power to return home. After initial confusion, the 1955 Doc Brown agrees to help Marty get back home by striking his car with 1.21 gigawatts of lightning, giving Marty a week to make his parents fall back in love at a dance and put bully Biff Tannen in his place. He does it, and in the process invents rock 'n' roll and skateboarding.

For tropes found throughout the trilogy, like "Mister Sandman" Sequence, see the franchise page, Back to the Future. For tropes specific to this film, see below.

---

Back to the Future provides examples of:

Tropes #-E

• 555: Doc Brown's phone number in 1955 was KL5-4385, and Jennifer's grandmother's in the present is 555-4823.
• 12-Bar Blues: All Marty McFly has to tell his backup band in the dance party is, "This is a 'blues' riff in B," and they are able to properly accompany his rendition of Chuck Berry's "Johnny B. Goode" (until he starts channeling Eddie van Halen, anyway).
• Accidental Time Travel: The DeLorean time machine starts out barely averting this: it runs on plutonium, which Doc Brown has a small stockpile of. However, Marty accidentally travels back in time trying to escape some vengeful Libyans, not noticing that he turned on the time circuits before trying to outrun them at 90 miles per hour (time travel is possible at 88mph). It fully turns into this trope because he didn't travel with Doc's plutonium stockpile, leaving him stuck in 1955 and having to figure out an alternate power source.
• Achilles' Power Cord: Doc Brown needs to connect a power line from the top of the clock tower, where a lightning bolt will strike, to ground level, where the DeLorean will use the energy to travel through time. Unfortunately, a random lightning strike knocks a tree branch onto the power cord so it doesn't reach as far anymore, so he has to improvise.
• Acoustic License: Realistically, the sound coming from an amplifier on the other side of a cavernous, noisy gym, combined with a 1950s long-distance telephone connection, should have been distorted beyond all recognition.
• Activation Sequence: The first scene is Marty arriving at Doc's place where he starts activating... something. He switches on the power, activates all the switches, dials up the driver and the overdrive, causing all the dials to go off-scale high. Then we see that what he's powering up is a giant speaker, which blows him across the room, and blows itself up, when he tries to play a chord on his guitar.
• Actor Allusion:
  • Marty's brother Dave donning a Burger King uniform may have been a tribute to Lea Thompson's early acting gigs as a Burger King spokesperson. Incidentally, in those ads Thompson appeared alongside Elisabeth Shue, who would later play Jennifer in Part II and Part III.
  • Huey Lewis, playing the audition judge in 1985, tells Marty's band that they're "just too darn loud." The band was playing Lewis' own song, "The Power of Love." Better yet, the line was apparently improvised by him.
  • George tells Marty he'd rather watch Science Fiction Theatre than go to the dance. Michael J. Fox had to add a J. to his name because a Science Fiction Theatre actor named Michael Fox was in the Screen Actors Guild.
• Actually Pretty Funny:
  • George laughs when Skinhead mocks Marty for wearing a "life preserver".
  • At a meta level, the real Ronald Reagan got such a kick out of Doc Brown's disbelief that he would be president that he asked the projectionist to roll back the reel and play it again.
• Again with Feeling: When the 1955 Doc Brown listens to his future self in the video saying what is necessary to make the DeLorean travel in time, he repeats it in shock and disbelief because he hasn't the means to create so much energy.
  1985 Doc: No, no, no, this sucker's electrical, but I need a nuclear reaction... [Marty rushes the video] ...to generate 1.21 gigawatts...
  1955 Doc: [shocked] 1.21 GIGAWATTS?! [backs away and runs from the garage, repeating in despaired astonishment] 1.21 gigawatts!
• All Men Are Perverts:
  • Marty quickly finds out that George's idea of birdwatching before first meeting Lorraine was watching her undress from a tree with binoculars.
    Marty: [incredulously] He's a peeping tom!
  • Marty has a case of Male Gaze when two jazzercise girls walk past him; Jennifer quickly straightens him out.
  • In a much more serious case of Biff's rather aggressive infatuation with Lorraine, which she does not take well to.
• Almost Kiss:
  • Marty and Jennifer are playfully flirting in the courthouse square, and are an inch away from kissing...when they are interrupted by: "Save the clock tower! Save the clock tower!", complete with the lady shaking the donations tin in their faces. So much for that moment....
  • Moments later when Marty and Jennifer try to kiss again, Jennifer's dad arrives to pick her up.
  • And finally, at the end of the movie when Marty and Jennifer are reunited, Doc shows up once more with the DeLorean.
• Anachronism Stew: While the past is set in 1955, the guitar model Marty plays at the prom, a Gibson ES-345TD, was only introduced in 1958. In fact, Gibson didn't even introduce humbucking pickups to their electric guitar line until 1957 (their lap steel models received the pickup early in '56). Until that point, Gibson's electric guitars usually came equipped with P-90 pickups.
• And the Adventure Continues: Initially, when no sequels were planned, the ending was this. The adventure ended well, Marty ensured his existence is secured, his family's prospering and he reunites with his boo...and then Doc suddenly returns in the DeLorean to take them back to the future for more adventures.
  Doc Brown: It's your kids, Marty! Something has gotta be done about your kids!
• And This Is for...: When Biff's friends toss Marty in the trunk of the car:
  Skinhead: That's for messin' up my hair!
• Arbitrary Skepticism: Marty was in a time machine. Which he knew worked. And when he reached eighty-eight miles per hour, sparks surrounded the car and the view around him suddenly changed. Yet he takes a long time to realize he's in the past, and keeps saying it must be a dream. But then again, he doesn't sound like he believes himself. Justified, given that Marty only learned time travel was possible a few hours earlier (according to his perception), he'd lived a fairly normal life without any sci-fi experiences up to that point, and he hadn't slept much.
  Marty: (anxious; speeding down the road) Alright, alright, okay, McFly... get a grip on yourself... It's all a dream. Just a... (unsure) very... intense dream...
• Artistic License: When Doc indicates the birth of Christ as December 25, 0000. Of course, it is now accepted by educated people that Christ was born around 4 BC, but the big error is the fact that the Gregorian calendar does not include a year 0, only a 1 BC followed by a 1 AD — something that the inventor of a time machine should have looked into. In fact, the lack of a way to go back to BC at all is an odd choice on his part.
• Artistic License – Chemistry: Perhaps it could be combined with other crap, but plutonium isn't a red liquid. It's a silver metal.
• Artistic License – History: The Honeymooners episode "The Man from Space" is shown to be airing for the first time on November 5, 1955. In real life, the episode didn't air until December 31, 1955.^note In fact, the episode's central premise is that Ralph is dressing up for a New Years costume party. The actual episode that aired on November 5 was "The Sleepwalker". It’s not known if this stemmed from a failure of research, an issue with obtaining a clip from the correct episode, or if the image of Ralph dressed up as a spaceman was meant to be a call-back to the Peabodys thinking Marty was an alien.
• Artistic License – Gun Safety: Doc looks up the barrel of his Colt Single Action Army revolver with his finger on the trigger. Good thing it wasn't loaded.
• As Long as It Sounds Foreign: The Libyan terrorists speak vaguely Arabic-sounding gibberish. They do pepper it with accented English though. At one point, the terrorist shooting, whose weapon (an AK-47) had jammed, can be heard: "Damn Soviet gun!"
• Ask a Stupid Question...: A baffled Marty wakes up to see his family are prosperous, asks "What the hell is this?".
  Linda: ... breakfast.
• Attempted Rape: Biff with Lorraine in 1955. George shows up, thinking he was going to stop Marty from acting it out, but instead must actually stop Biff from doing the real thing.
• Auto Erotica: Marty's plan to get his parents together involves George finding him "parking" with Lorraine and trying to take advantage of her, then pulling him out of the car and pretending to beat him up to make him look like he's the tougher guy. Except Biff turns up instead of George, belligerently drunk, and he wants revenge on Marty for the $300 damage^note Over $3,000 in today’s money his car took in the manure truck incident, so he decides to attempt to molest Lorraine. Hence, George's "rescuing" Lorraine ends up becoming the real deal.
• Bait-and-Switch: After Marty's plan to stage a rape on his mom so his dad can rescue her fails, Lorraine notices someone coming to the car. Marty (and the audience) assumes it's George coming to do his part of the plan, only for the door to open and for him to be grabbed by Biff, who's pissed about the $300 damage to his car (which he himself was responsible for).
• Bait-and-Switch Comment: Marty, finding himself stuck in 1955, goes to meet the 1955 version of Doc to get his help to fix the time machine so he can return to 1985. Upon arriving at his house, Marty ends up becoming the subject to Doc's test with a mind-reading device, leading to this exchange:
  Marty: Doc, I'm from the future. I came here in a time machine that you invented, and I need your help getting back to the year 1985.
  Doc: My God... Do you know what this means? [beat] It means that this damn thing doesn't work at all!
• Been There, Shaped History: Back in 1955, Marty McFly plays Chuck Berry's "Johnny B. Goode" when he steps in for Chuck's cousin, Marvin Berry. While Marty is playing, Marvin calls Chuck up so he can listen in on this "new sound". He also gives the 1985 mayor Goldie Wilson, at that time the black janitor in the malt shop, political aspirations the exact year the Civil Rights Movement started. And of course, Marty ends up being responsible for his parents getting together and being a happier and more successful married couple in the future.
• Beethoven Was an Alien Spy: The movie suggests Chuck Berry invented rock and roll through a secondhand account from a time-traveler from the future.
• Big Damn Heroes: Played with. Marty and George's plan is to make it look like this when George comes to Lorraine's "rescue." But Biff got there first, had his gang take Marty away, and is actually trying to rape Lorraine when George shows up.
  George: Hey you, get your damn hands off... [realises it is Biff] oh...
  Biff: I think you got the wrong car, McFly.
  Lorraine: George, help me! Please!
  Biff: Just turn around, McFly, and walk away.
  [George hesitates]
  Biff: Are you deaf, McFly? Close the door, and beat it.
  Lorraine: [whispering, frightened] Please, George....
  George: ...No, Biff. You leave her alone.
• The Big Damn Kiss: George and Lorraine at the dance, complete with "Earth Angel" swelling on the soundtrack, and saving their son's entire existence.
• Big Heroic Run: After Marty gets back to 1985 and the DeLorean stalls on him, he is forced to run to the mall to prevent Doc from being shot. It fails because he gets there just as Doc is shot. Fortunately, Doc survived and wore a bullet-proof vest, thanks to being forewarned by Marty's letter, which he kept and taped back together.
• Big "NO!":
  • Marty after Doc is shot by the Libyans.
  • In TV versions, Biff and his goons do this instead of collectively yelling "SHIT!" as they crash into the manure truck.
• Bizarre Beverage Use: When Doc shows up at the end, he powers the DeLorean's Mr. Fusion with a bunch of trash he finds rummaging in the McFly trash can, including a partially-full can of beer, which he pours into Mr. Fusion, then dropping the can in as well.
• Bizarre Dream Rationalization: After getting shot at by Libyan terrorists, then traveling back in time, THEN getting shot at again by Farmer Peabody, Marty tells himself that this is all just a "very intense dream."
• Blaming the Tools: When Biff wrecks George's car at the beginning of the film, he blames it on a blind spot George failed to tell him about, combining this with Never My Fault.
• Bloodless Carnage: There's no blood when Doc is riddled with bullets. In the changed timeline, it's because he's wearing a Bulletproof Vest.
• Blown Across the Room: It isn't done with a gun, but Marty tries to use an electric guitar attached to a huge amplifier and speaker. After he does one strum on his guitar, the audio from the speaker blows him across the room.
• Book Ends: In a way. Marty accidentally time travels to 1955 with the Back to the Future theme playing in the first 30 minutes, and then he travels back to 1985 in the last 10 minutes or so with the BTTF theme making a Triumphant Reprise.
• Borrowed Catchphrase: "If you put your mind to it, you can accomplish anything." Doc never actually says it in the movie (or the rest of the trilogy), but Jennifer attributes it to him. Only Marty and George ever say it — in fact, it seems that George has adopted it as his own catchphrase at the end of the movie.
• Breaking the Fourth Wall: When Doc says to Marty that next Saturday night he'll send him back to the future he points his finger at the screen.
• Brick Joke: Within the first half-hour of the film, Marty is sent back in time while speeding through the parking lot of Twin Pines Mall. Shortly after arriving in 1955, he runs over and destroys one of the two pine trees growing on the property that would eventually become the mall. At the climax of the film, Marty returns to the mall parking lot, where the sign indicates it is now known as "Lone Pine Mall".
  Old Man Peabody: My pine! Why, you... ! You space bastard! You killed my pine!
• Brother–Sister Incest: Invoked. Lorraine is coming hard onto Marty, kissing him back into a corner, and it suddenly occurs to her that it's like kissing her brother. She is Squicked, although not nearly as much as Marty is, knowing that it's really Parental Incest.
• Buffy Speak:
  Marty: Time circuits, on. Flux capacitor... fluxing.
• Bulletproof Vest: When Marty returns to 1985 and tries to reach Doc before the Libyans shoot him, he arrives too late... although Doc eventually reads the letter anyway after taping it back together and was secretly wearing a bullet-proof vest.
• Bully Brutality: Biff Tannen engages in this by using his car to try and run a skateboarding Marty into a manure truck.
• Butterfly of Doom: Much of the movie revolves around Marty trying to reverse the effect of his having saved his father from being hit by a car.
• Buy or Get Lost: The first place Marty goes after he's in 1955 is the local sandwich shop to try to find a phonebook so he can locate Doc Brown. Despite only being in the place for less than a minute, when he tries to ask the cook how to find a certain street, the cook brusquely asks him if he's going to buy something or not.
  Marty: Gimme a Tab.
  Lou: A tab? I can't give ya a tab unless you order something.
  Marty: Right. Give me a Pepsi Free.
  Lou: If you want a Pepsi, pal, you're gonna pay for it!
• Came from the Sky: Lampshaded. After crashing the time machine into a barn, Marty emerges to find himself face to face with a farmer with a shotgun, and the farmer's son holding a comic book depicting a crashed alien ship and a figure wearing a space suit startlingly similar to Marty's.
• The Cameo: Huey Lewis is the teacher who tells Marty that his music was "too darn loud".^note Marty is playing an instrumental version of Huey Lewis' own song, "The Power of Love".
• Car Fu: Biff attempts to run over "Calvin Klein" (Marty) through Courthouse Square. He ends up crashing into manure.
• Car Hood Sliding: Marty performs one to quickly get into the DeLorean for the lightning strike coup.
• Celebrity Paradox:
  • Huey Lewis exists in the BTTF universe, as proven by Marty's posters in his room — and so does the audition judge, played by... Huey Lewis. Even better: at the end of the movie, Marty's clock radio plays "Back in Time" by Huey Lewis and the News. The song was specifically written for (and contains a ton of references to) a little movie called Back to the Future. Marty is even referred to by name in that song. Granted, the song is cut specifically to avoid any references to the movie.
  • When pretending to be an alien to George, Marty references Star Trek. Christopher Lloyd, who played Doc, portrayed Kruge in Star Trek III: The Search for Spock, while Lea Thompson, who played Lorraine, would later make an appearance in Star Trek: Picard. He also references Star Wars. Lloyd would appear in The Mandalorian as Commissioner Helgait, while Flea, who played Needles in the sequels, would later appear in Obi-Wan Kenobi as Vekt Nokru.
• Chekhov's Armoury: The movie is absolutely riddled with these, with almost everything significant in 1985 coming back in 1955; the last day Doc puts in the time circuits,^note It is the day he came up with the flux capacitor, which Marty uses to win past Doc over. Marty's band wanting to play at the dance,^note His guitar playing comes into effect when he plays at the 1955 dance. Jennifer's phone number,^note Written on the otherwise unwanted note about the exact time the clocktower was struck and Lorraine's love story^note Explains how Marty nearly erases himself and tells him how to make them fall in love again. are just a few examples of very important (but seemingly minor) details.
• Chekhov's Boomerang: Marty's radiation suit. At first, it's to protect him from the radiation of the plutonium in the DeLorean, and gets mistaken for an alien while inside it, but he later uses it to convince George that he's an extra-terrestrial named Darth Vader from the planet Vulcan.
• Chekhov's Gag: The joke about the TV show they're seeing at the Baines' house in 1955. It's seen earlier at the McFly's house in 1985, and as Marty watches the same episode in 1955, he notes that he's seen it and it's a classic, to which one of his uncles replies that it's brand new and it's impossible that he could have seen it. Marty says he saw it on a rerun, prompting more confusion from them.
• Chekhov's Gun:
  • At the start of the film, Marty is conveniently given a flyer by a woman who (along with other volunteers) is attempting to raise money to save the historic clock tower. The scene is played for laughs, but the flyer contains crucial information on how to return to the future, including the exact date and time that the clock tower was struck by lightning. And the only reason Marty probably kept it (and kept it on him, so he had it in 1955 when he needed it) is because Jennifer wrote her grandmother's phone number on it so Marty could call her there.
  • Lorraine tells the kids that if her father hadn't hit George McFly with his car in 1955 before the dance, none of the kids would've been born. She also says that she and George fell in love after they had their first kiss at the dance. It looks like it's just informing us about how the romance has gone out of their marriage. It's not.
  • When Marty is leaving Doc Brown's home after the opening scene, he is seen putting his headphones on (connected to a Walkman). He later uses the Walkman to intimidate George.
  • Ironically for a light-hearted sci-fi comedy, the film is often used as a perfect example of this trope, since virtually every single thing that happens in the film exists to set up a later event.
• Chekhov's Gunman: Dixon, the guy who cuts in on George and Lorraine at the dance, was previously seen kicking George around when he had the "Kick Me" sign on his back.
• Chekhov's News: A random passerby mentions the 30th anniversary of a terrible lightning bolt that struck the clock tower in 1955. At the end of the movie, since plutonium was very rare at the time, 1955 Doc Brown uses the power of the bolt to fuel the DeLorean and get Marty back home.
• Chekhov's Skill:
  • At the beginning of the movie, Marty is practicing his guitar playing, and he's also shown to be good at skateboarding and hitching a ride on the back of a car. All of those skills come in handy to him in 1955.
  • The whole scene of the Pinheads auditioning was purely to show that Marty could play guitar in front of an audience, as he will do in 1955 (and in the exact same location, too).
• Chekhov's Time Travel: Outside of some vague Foreshadowing and the film's own title, there's zero indication that it's about time travel. Then Marty meets Doc at a parking lot to film an ultimately successful test of his latest invention: the DeLorean Time Machine. Per this trope, Marty accidentally uses it trying to escape from the Libyans a few minutes after the test.
• Chewing the Scenery: Surprisingly, Marty — near the end of "Johnny B. Goode". His faces while he goes over-the-top are... interesting. However, the rest of the school doesn't think it's nearly as cool as he does, just staring at him after his guitar solo.
• Clean Up the Town: Goldie Wilson, in 1955 a busboy at Lou's Diner, imagines himself as doing this after Marty recognizes him as the future mayor and tells him that. Lou hands him a broom and tells him he can start by sweeping the floor.
• Clock Discrepancy:
  • Marty is at Doc Brown's house and thinks he will be on time for school, only to discover all his clocks are twenty-five minutes slow.
  • Doc Brown proves to Marty that the time machine works by synchronizing watches with a digital clock he attaches to his dog, then sending the dog one minute into the future. When the dog shows up again, his clock is a minute slower than Doc's.
• Clockworks Area: Doc strings the cable from the clock tower to power the DeLorean at 1.21 gigawatts. Unfortunately, the storm brings down a tree limb, causing the end at the clock face to become unhooked. He climbs through the clock's gears to get to the door on the face so Marty can feed him the cable to re-hook it.
• Close-Enough Timeline:
  • Since Marty has to get his parents together but can't recreate the exact circumstances of their first meeting, he ends up unwittingly changing the timeline. In the old 1985, George was a meek office drone who was still bullied by Biff 30 years later, and Lorraine is a prudish alcoholic trapped in a loveless marriage. Thanks to Marty giving George confidence and helping him and Lorraine get to know each other as people, in the new timeline George is a successful author, his relationship with Lorraine is full of passion and life (which has a spillover effect of improving their children's lives too), and a humbled Biff runs an auto detailing business while deferring to the much more successful George. When Marty briefs Doc of the spectacular success at the dance to Doc, his reaction indicates that Doc suspects this will be happening.
    Marty: He [George] laid out Biff in one punch. I never knew he had it in him! He never stood up to Biff in his life!
    Doc: [concerned look] ...Never?
    Marty: No, why, what's the matter?
    [Doc has no time to explain due to the upcoming lightning strike]
  • It also tips Doc off that changing the natural course of time isn't always the catastrophe he feared it would be, (as the picture indicates that Marty and his siblings' chronal elimination has been successfully reversed despite the changes to the timeline) and he later tapes up and reads Marty's letter.
• Clown Car: Biff's goons make the mistake of insulting Reginald, one of The Starlighters, outside his Cadillac, causing Marvin and three of his fellow band members to exit the car.
• Coincidental Broadcast: At the beginning of the movie, Doc Brown's TV is automatically turned on just before Marty arrives. It shows a news broadcast about the theft of some plutonium by some Libyan terrorists. After Marty arrives the audience is shown a box containing plutonium underneath a bed, and it later turns out that the terrorists stole the plutonium in the hope that Doc Brown would use it to create an atomic bomb for them.
• Combat Pragmatist: Marty has no problem sucker-punching Biff, or running straight through Biff's convertible when he's about to be rammed into the back of a manure truck.
• Comically Missing the Point:
  • It initially sounds as if Marty is amazed by the time machine. Then he adds the phrase, "out of a DeLorean?!"
  • In 1955, when Marty tells Doc who he is while using the mind-reader:
    Marty: Doc, I'm from the future. I came here in a time machine that you invented, and I need your help getting back to the year 1985.
    Doc: My God... Do you know what this means? [Beat] It means that this damn thing doesn't work at all!
• Confidence Building Scheme: Played with; Marty concocts a scheme to pretend to take advantage of Lorraine so George can pull a fake rescue and kiss her (not to boost George's confidence per se, but to make them fall in love and eventually become Marty's parents). However, Biff throws a Spanner in the Works by having his goons lock Marty in a car trunk and forcing himself onto Lorraine. George finally stands up to Biff and knocks him out, and Lorraine falls for him for his courage - instead of feeling sorry for George as she did in the original timeline. When Marty returns to 1985, he finds George has grown into a self-confident man and improved their whole family's life.
• Contrived Clumsiness: Marty "accidentally" trips Biff when they're in the diner in 1955 Hill Valley.
• Contrived Coincidence: Doc types in "November 5, 1955" into the time machine, the day he came up with the Flux Capacitor. Marty ends up going back to that day, which also happens to be the exact same day his parents met. It's also lucky for Marty that the dance where his parents first kissed and fell in love happened before lightning hit the clock tower, the only time Marty and Doc knew of when and where lightning would strike, as opposed to after. It also is pretty convenient that said strike happened to be within a week of when Marty arrived, close enough that he wouldn't have to wait long to go back, but long enough for Doc to use this information to come up with a plan that works. And they only know it because Marty happens to have been handed a "Save the Clock Tower" flier that day — that happens to include a copy of a newspaper article from the day the lightning hit; which he happens to have kept only because Jennifer happened to use it to write down her phone number for him plus a love note, and happens to decide to show to Doc because when Marty happens to have mentioned that he has a girlfriend as one of the reasons he can't stay in 1955, Doc happens to bother asking how things are between him and his girlfriend back home...
• Convenient Slow Dance: "Earth Angel", where George and Lorraine kiss just before Marty gets erased from history.
• Cool Car: Enforced with the DeLorean; the page quote shows why. Unfortunately for history, the DeLorean never got its money's worh out of the advertising. Nor did anyone who bought one.
• Cringe Comedy: Lorraine's unrequited crush on her (future son) Marty oozes this.
• Cue the Falling Object: After Marty flies backward after effectively destroying a large amp by turning it up too high, a small part of the amp breaks off and falls to the ground.
• Curse Cut Short: Some TV versions invoke this trope when Marty travels back to 1955. When Mr. Peabody shoots at Marty through his closed barn door before he drives out, Peabody shouts, "Take that, you mutated son of a bitch!" Whereas in some TV prints, Peabody's line is cut short to:
  Mr. Peabody: "Take that, you mutated son of a—"
  (Marty bursts out of the barn)
• Damsel in Distress: Invoked and then played straight — Marty's plan is to stage an Attempted Date Rape of Lorraine (his own mother) so that George can intervene and win Lorraine's affections, which goes awry when Marty can't bring himself to do it and Lorraine is more willing to do risqué things than Marty thought. However, when Biff interrupts the staged attempted rape and tries to actually rape Lorraine, it's up to George to save the day, which he does, achieving an even better result, because the show of assertion against Biff was for real and not only did wonders for George's self-confidence, it changes Lorraine's former pity for him into admiration for his bravery.
• Dance of Romance: George and Lorraine fell in love at the Enchantment Under the Sea dance.
• Dances and Balls: The "rhythmic ceremonial ritual"; also a High-School Dance, one where Marty's parents are supposed to fall in love. Actually getting them to that point after Marty accidentally prevents their first meeting is the plot of most of the film.
• Date Rape Averted: Invoked with Fake Danger Gambit, then doubly subverted: Marty sets up a plan to pretend to go too far with Lorraine in their car date; cue George stepping in, grabbing Marty off her and being the hero. Two things cause the plan to go awry: 1) Marty very understandably can't go through with it (in fact Lorraine is far more eager to advance things than he is), and 2) Biff enters the scene, gets his goons to remove Marty from the picture and then turns back to Lorraine and begins trying to rape her for real. Then George steps in and thwarts him, also for real.
• Dated History: Doc keeps a portrait of Thomas Edison alongside similar portraits of Albert Einstein, Sir Isaac Newton, and Benjamin Franklin (the 1955 Doc addresses his Edison portrait when he's shocked that it takes 1.21 gigawatts to power the flux capacitor). In later years, it became more well-known that many of Edison's "inventions" were actually created by his European immigrant employees (most notably Nikola Tesla's work on the electric lamp), his sole output in many cases being taking the credit for them, and his generally less-savory behaviors (i.e. patent-trolling in the film industry or his propaganda campaigns against alternating current) became more well-known.
• The Day the Music Lied: During the climactic time-travel sequence, the Theme Music Power-Up is heard as Doc is about to connect the cables to the clock tower... and is interrupted when Doc realizes he doesn't have enough cable because part of it is stuck under a broken tree branch.
• Deadpan Snarker: Lou, the owner of the diner where Marty meets the George in 1955, starts out by making snarky comments about Marty's jacket. Then there's his exchange with his employee, Goldie Wilson:
  Goldie: I WILL be mayor [someday]. I'll be the most powerful man in Hill Valley, and I'm gonna clean up this town!
  Lou: Good. You can start by sweeping the floor.
• Death Glare:
  • Marty gives one to Biff after stopping him from attacking George by tripping him up - which almost immediately turns into an Oh, Crap! when he realizes that Biff is twice his size.
  • Strickland has one of these just after "Calvin" finishes "Johnny B. Goode" at the dance.
• Defeat Means Friendship: By the end of the movie, Biff is a friendly (if sycophantic) worker for George after George beats the crap out of him in the past.
• Delayed Ripple Effect: Marty has a week to get his parents together before he'll be erased from existence.
• Deliberate Values Dissonance: Even if it's a family-friendly film, it doesn't shy away from depicting the overt racism of America in The '50s. Even Biff's overt sexual harassment of Lorraine doesn't raise many eyes.
• Department of Redundancy Department: The reason the "Darth Vader" scene was shortened. In the full-length scene, "Vader" tells George that he will melt his brain if he doesn't take Lorraine to the dance — information George relays to Marty in the very next scene. The version in the film has the "Darth Vader from the Planet Vulcan" line before cutting to George telling Marty about it the next day.
• Despite the Plan: Marty McFly concocts a plan to get Lorraine to fall for George McFly. Biff unexpectedly intervenes, shattering the plan for George to pretend to deck Marty and rescue Lorraine. Fortunately, George manages to deck Biff and rescue Lorraine for real. Ironically, Biff's intervention saves The Plan from becoming A Simple Plan with its ensuing hilarity. In concocting the plan, Marty didn't quite get how his own conduct had seriously attracted Lorraine.
• Didn't Think This Through: Marty & Doc's plan to get Lorraine to fall for George involves Marty staging an Attempted Rape with George intervening and "saving" her. However, once the realization hits Marty that he has to actually hit on Lorraine, he can't bring himself to do it and is only able to nervously ask her if she wants to "park." Then the plan gets completely derailed when not only does Lorraine say yes, but she reveals that she's a pretty rebellious teenager by 1950s standards.
  Marty: Do you mind if we... "park"... for a while?
  Lorraine: That's a great idea, I'd love to "park".
  Marty: Huh...?!
  Lorraine: Well, Marty, I'm almost 18 years old. It's not like I've never "parked" before.
• Dirty Cop: While Doc is rigging the lightning rod, a cop comes along and asks him if he has a permit for his "weather experiment". Doc instead hands him an undisclosed amount of money so the cop would leave him alone. The extended cut shows him handing over $50, which, given that's around $530 in today's money, is being very generous. (Given the relative wealth of Doc in 1955, the relative poverty of Doc in 1985, and the general demeanor of Doc at any point in history, he may have spent a lot of money doing this over the years.)
• Disney Death: Doc Brown in the revised timeline, thanks to a warning from Marty, manages to avoid getting shot to death by wearing a bullet-proof vest.
• Diving Save: Marty pushes George out of the way of Lorraine's father's car, by accident.
• Dramatic Irony: The movie loves taking advantage of its time travel plot.
  Lorraine's father: Lorraine, you ever have a kid like that [Marty], I'll disown ya.
• Dramatic Thunder: Inverted. Thunder foreshadows the approaching dramatic storm — but this is a good thing, a critical plot point, to get Marty back home.
• Draw Aggro: Doc runs into the terrorists' view and tries to shoot at them in order to get their attention off Marty. In the original timeline, it costs him his life.
• Dysfunctional Family: The entire McFly family, but especially George and Lorraine, at the beginning of the movie.
• Ear Ache: After Doc rips up the letter, Marty attempts to verbally warn Doc about his pending demise at the hands if the Libyans and manages to get his attention and is able to tell Doc, who is on the ledge right next to the clock face, "On the night I go back in time, you get..." but is cut-off by the clock tower chiming at 10:00 pm at the dot. Since it's intended to be heard at great distances and Doc is so close, the first gong is so loud it startles him so badly he almost falls off the ledge and upon dragging himself back up, finds himself looking into the internal mechanism just as the hammer strikes the bell again, making him howl in pain.
• Early-Installment Weirdness:
  • A prominent plot point in the sequels is that Marty intensely dislikes being called a "chicken" and that this insult can be used to manipulate him into doing reckless things. This character trait never shows up in the first movie, although there is one slight moment:
    [After telling Lorraine that she shouldn't drink]
    Lorraine: Anyone who's anyone drinks.
    [Marty reluctantly takes a swig out of the flask and spits it out in disgust]
  • The DeLorean needs to hit 88mph and then sustain that speed for a few seconds before it travels in time. In all future installments, the time-traveling kicks in the instant the car hits the required speed. This might be due to it using Mr. Fusion as its power source instead of plutonium, also making this the only instance in the franchise where the latter is true.
  • Additionally, in this film, the DeLorean breaks down twice during the climax of the film, true to how unreliable the car was in real life. In the next two films, the car's engine does not break down in the same way again.
• Early Personality Signs: Marty's Uncle Joey is in prison in 1985. When Marty goes back to 1955, he sees Uncle Joey as a baby. Turns out the infant Uncle Joey loves being in his barred playpen and cries whenever he's taken out.
• Easily Forgiven: While Biff in the altered timeline appears to have become a harmless, eager-to-please Gentle Giant who is barely recognizable as the bully he used to be, both George and Lorraine seem to be remarkably grudge-free about him trying to kill their friend and rape Lorraine.
• Eating Lunch Alone: George in 1955 tends to eat by himself in the cafeteria and focus on writing his ideas for a science fiction book down on paper.
• Eleventy Zillion: To modern ears, the movie's famous "1.21 jiggawatts" sounds like this, but it's really just an outdated pronunciation of "gigawatts"^note It's the same prefix computer terminology would use for a term like "gigabyte".
• Emergency Temporal Shift: After seeing the Libyan terrorists shooting Doc Brown, Marty McFly finds himself next in the firing line and is forced to escape via the newly-completed DeLorean time machine — traveling from 1985 to 1955.
• Entertainingly Wrong: 1955 Doc does this a few times. When he sees his older self wearing a radiation suit on video, he assumes that it's because of the effects of future atomic wars. Later, when Marty tells him all they need is "a little plutonium" to make the time machine work, he thinks this means plutonium is an easily accessible resource in 1985.
• Eskimos Aren't Real:
  • In 1985, Goldie Wilson is running for re-election as mayor of Hill Valley. In 1955, when Marty sees Goldie is the busboy at Lou's, he gives him the idea to become mayor. Goldie's employer, the owner of the cafe, scoffs at the idea of a "colored mayor". There had been a number of African American mayors prior to 1955, though it should be noted that said mayors oversaw small rural frontier towns, and it wasn't until the 1967 elections of Richard B. Hatcher of Gary, Indiana and Carl B. Stokes of Cleveland, Ohio that there were African-American mayors running large cities.
  • Doc doesn't initially believe that an actor like Ronald Reagan could become president, though he comes around to it when he sees Marty's "portable television studio" (really a video camera) and realizes the president has to look good on film^note an accurate and unusually insightful assessment for the time, as the importance of your appearance on TV would not become well-understood for another 5 years during the Kennedy-Nixon debates, where Kennedy both looked better (due to wearing makeup, which Nixon eschewed), and he "worked" the camera better, coming off as the winner. If you simply read a transcript, Nixon comes off as by far the superior candidate who knows what he's talking about, while Kennedy gives bland, largely meaningless answers that show a relative lack of understanding.
• Establishing Character Music: The first time we see Marty McFly, he walks into Doc Brown's laboratory, plugs in his guitar, and begins shredding. This quickly establishes him as a laid-back, average teenager.
• "Eureka!" Moment:
  • Marty has one when he reads the flyer given to him by the woman campaigning to save the clock tower and realizes that the bolt of lightning can be harnessed to give the time machine enough power to send it back to 1985.
  • In 1955, just before Marty's arrival. Doc was hanging a clock in his toilet when he slipped and fell and banged his head on the sink.
    Doc: And when I came to, I had a revelation. A vision! A picture in my head. A picture of this! This is what makes time travel possible: the Flux Capacitor!
  • After Doc tears up Marty's letter about his future, Marty laments that he doesn't have enough time to warn him. He then realizes that he can give himself enough time by setting the destination time on the time machine back by 10 minutes.
• Everybody Lives: None of the characters who appear in the movie dies. Not even Doc Brown, because Marty's seemingly-failed attempt to warn him about the Libyans murdering him in 1985 actually succeeds, as Brown cheats death by wearing a Bulletproof Vest.
• Every Car Is a Pinto: Averted with the Libyans' van, which merely tips over after hitting the photo booth. On the other hand, this does create a plot hole, since the terrorists are treated as no longer being a threat after this even though they apparently survived.
• Evil Redhead: Dixon, the cackling punk who cuts in on George's dance with Lorraine.
• Exact Words: George won't try to ask Lorraine to the dance, telling Marty that "not you, nor anybody else on this planet, is going to make me change my mind." That night, Marty pretends to be "Darth Vader," an "extra-terrestrial from the planet Vulcan."
• Expo Speak Gag: Doc treats getting George and Lorraine together in a way akin to someone narrating a nature documentary and describes the school dance as a "rhythmic ceremonial ritual".

Tropes F-N

• Face Fault: Marty falls over in shock when he sees his parents completely changed by the end of the movie.
• Face Plant: When Marty makes some small talk with 1955!Lorraine, Lorraine's mother calls them down, causing Lorraine to tussle around to avoid Marty getting into a Caught with Your Pants Down scenario. This is the result.
• Fading Away: This happens to Marty when he's in danger of nullifying his own existence through a time paradox when his parents might not get together.
• Failed Future Forecast: Doc assumes that radiation suits are used in 1985 because of fallout from the atomic wars, and presumes that plutonium may be available in pharmacies by then.
• Fake Danger Gambit: This is how the time-traveling Marty McFly tries to get his parents to fall in love. Marty will drive Lorraine to the school dance, then start to make out with her in the parked car, then George McFly will arrive to "punch" Marty and "rescue" Lorraine from his unwanted advances. It goes wrong twice: first, Lorraine is far more eager to make out than Marty anticipated. Second, Lorraine's first "rescuer" is actually the bully Biff Tannen, who intends to take advantage of Lorraine for real. And in spite of these complications, the plan works better than intended: blissfully unaware, George arrives right on cue, and the sight of Lorraine in genuine danger gives him the strength to punch out Biff for real, and Lorraine immediately falls for him.
• False Start:
  • George, with Lorraine in 1955. It was meant to go down as normal until Marty pushed George out of the way from being hit with a car.
  • Later, as George is stumbling his way in wooing Lorraine at the cafe, it seems like he'll succeed until Biff shows up.
• Fantastic Romance: Marty is accidentally sent back in time from 1985 to 1955, and - with the help of a younger version of Doc Brown, the inventor who built the time machine - make sure that his parents fall in love after he unintentionally prevents their original meeting, as well as return home to his own girlfriend, Jennifer, back in The '80s.
• Fan Disservice: While there's no doubt that young Lorraine is a very attractive girl, she has the hots for her future son (she doesn't know it, in her defence). Marty in-universe is obviously abhorred by that.
• Feedback Rule: The mic gives off a slight feedback whenever Marty speaks into one, first during his audition with his band and then later at the High-School Dance.
• Feet-First Introduction: Marty. You don't even get to see his face until he takes off his sunglasses a minute and a half later.
• First Contact Farmer: Marty crashes into a pine tree, a scarecrow, and a barn upon arriving in 1955. He crawls out of the DeLorean and tries to apologize to Farmer Peabody. However, he's wearing a radiation suit and the farmer's son has already identified the car as a spaceship, so he just winds up having to drive away for his life when Farmer Peabody goes for his gun.
• First-Episode Twist: The time-travel aspect in the movie was a complete surprise to test audiences in 1985, since the first fifteen minutes of the film seem like an Eighties teen movie (albeit with a quirky scientist as a side character, who in the opening is implied to be experimenting with clocks), and it was one of the first time-travel comedy films, a genre that would subsequently become much more common.
• First Kiss: George and Lorraine have theirs during the Enchantment Under the Sea Dance, while the band plays "Earth Angel". Marty has to fill in for a band member who injured his hand to ensure that it happens.
• Fist of Rage: George clenches his fist when seeing Biff mistreating Lorraine.
• Five-Second Foreshadowing:
  • There's a shot of the Delorean's time circuit readout just before Marty reaches 88 mph and travels back in time, giving a pretty good indicator of what's going to happen next.
  • While Doc is explaining to Marty how difficult it would be to generate 1.21 gigawatts of power, Marty pulls out the Save the Clock Tower flyer to show Doc something written on the back, giving the audience a good look at the headline about the clock tower being hit by lightning. This helps the audience keep up when, a moment later, Marty realizes that the lightning hitting the clock tower could be his ticket home.
  • When Marty, having arrived back to 1985 and after witnessing Doc getting shot all over again, rushes to his friend's lifeless corpse and turns him over, there's no blood oozing from the bullet wounds. This indicates that Doc had worn a bulletproof vest.
  • The first time we see Doc get shot by the Libyans, he gets shot dozens of times and actually gets knocked backward as he falls. The second time we see this, he falls much faster in a staged-looking manner.
• Florence Nightingale Effect: Lorraine fell in love with George after her dad hit him with his car. Marty accidentally ends up replacing his father in her affections when he pushes George out of the way. Marty is naturally not okay with this, and inadvertently keeps making himself even more attractive to her. Especially after he defends her from Biff in the school's lunchroom. Doc calls out the trope by name to explain to Marty what's going on. invoked
• Fly-at-the-Camera Ending: The movie ends with the DeLorean flying up in the air, turning around, then warping through time just as it hits the camera.
• Flying Car: Doc Brown apparently did a lot of work on the DeLorean in the future and this is one of the upgrades he made. The final shot of the film shows the car's wheels turning to face downwards for levitation before it takes off to the air and to the future.
• Foreshadowing:
  • Early in the movie, Jennifer and Marty see a black 4x4 Toyota pickup truck, and Marty says how great it would be to drive it up to the lake. At the end of the movie, after Marty has altered history, he discovers that his family now owns the very same truck and they are fine with Marty and Jennifer driving it up to the lake.
  • 1955 Doc commenting on how Marty's 1985 photo is obviously a forgery, since the top of his brother's head has been cut off.
  • One of the clocks seen at the start of the film shows a man hanging off of the minute hand (on the surface, a tribute to Harold Lloyd (no relation) in the climax of Safety Last!). Doc is later hanging off the clock tower face towards the end of the film. Also, the clocks are slow, with Marty being told of this, which sets up that he is going to go back in time later.
  • Marty's skateboard at the beginning hits a case of plutonium when Marty enters the garage. As revealed later, Doc had stolen it from the Libyans who later shoot him dead. Before that, Doc's TV was automatically turned on, which shows the news talking about a stolen case of plutonium.
  • The following exchange at the beginning:
    Strickland: Now let me give you a nickel's worth of free advice, young man. This so-called Dr. Brown is dangerous. He's a real nutcase. You hang around with him, you're gonna end up in big trouble. [...] No McFly has ever amounted to anything in the history of Hill Valley!
    Marty: Yeah, well, history is gonna change.
  • Biff in 1985 telling Marty to say hi to Lorraine for him may seem like a clumsy attempt to be nice, but it's meant to foreshadow that in her better days, Lorraine was very good-looking and that Biff has a Villainous Crush on her.
  • Upon being rejected for the Battle of the Bands, Marty says "I'll never get to play in front of anybody..." Guess what Marty does at the dance in 1955?
  • While recollecting how they first met, Lorraine has no idea what George was doing when he got hit by her dad's car. She presumes it was bird-watching but he doesn't confirm this. Later, Marty learns first-hand that what he was really doing was something other than bird-watching.
  • The McFly family is watching the episode of The Honeymooners where "Ralph dresses up as the man from space". The Baines family in 1955 watch the same episode when Marty is with them. It also sets up Marty being mistaken for a "man from space", first of all in front of the Peabodys when Marty first arrives in 1955 and later when he turns up in George's bedroom to coerce him to take Lorraine to the dance.
  • When Marty gets to 1955 and crosses the street in front of the movie theater in the town square he is nearly hit by a car. Guess what happens a few scenes later?
  • After the chase around the town square, Lorraine tells Marty that a man should stand up for himself to protect the woman he loves. George later does exactly this on the night of the dance, standing up to Biff for the first time in his life to save Lorraine.
  • Marty trips up Biff in the diner, and then punches Biff in the face before the chase around the town square. Near the climax, George stands up to Biff by punching him in the face, knocking him out.
  • When Marty tells Doc near the end that he never saw his dad stand up to Biff in his life, Doc's concern is piqued. Astute viewers can cue in that the 1985 that Marty will return to may not be quite the same in noticeable ways...
  • When Doc tears up the letter Marty wrote to his future self, he shoves the pieces in his pocket instead of throwing them away.
  • When Marty and Doc test the plan to send Marty back, the test car drives through the movie theater at the end of the block after being electrocuted. Guess what happens when Marty comes back to 1985.
  • "If Grandpa hadn't hit him, then none of you would have been born." And that's precisely the scenario that Marty creates later on.
  • A retroactive one for Part II. Just before the Libyans attack, Doc remarks that his trip to 2010 means, among other things, that he'll be able to learn who wins the next 25 World Series. In the next film, Marty and Doc will learn the hard way what happens when someone abuses future sports knowledge.
• Freeze-Frame Bonus: In the first movie, 1955-Doc has no less than four separate watches (one's even built into his clocktower model as the clock).
• From the Mouths of Babes: "It's already mutated into human form! Shoot it!"
• Funny Background Event:
  • Stella keeps removing Milton's coonskin hat while Marty is taking in the surroundings of the Baines' dining room.
  • When Biff says "Make like a tree... and get out of here", one of his goons turns his head towards him, and his eyebrows slowly try to crawl their way up to his hairline.
  • The Starlighters' saxophone player actually seems to enjoy Marty's segue into heavy metal during "Johnny B. Goode", and manages to keep up with him right until the end (when even he's looking on in disbelief).
  • In Lorraine's bedroom when Marty is struggling to get his jeans on, Lorraine can be seen in the mirror just before running out of the door - her face at the sight of Marty in his Calvin Kleins is quite revealing.
• Fun with Homophones: Marty attempts to get a Tab, and then a Pepsi Free, at Lou's Cafe in the '50s. "Tab" was introduced in the '60s as a sugar-free soft drink that was the predecessor to Diet Coke, but Lou thinks he means the tab, as in the money that he owes. Pepsi Free was introduced in 1982, and is better known nowadays as "Caffeine-Free Pepsi".
  Lou: You want a Pepsi, pal, you're gonna have to pay for it!
• Gale-Force Sound: Marty hooks up an electric guitar to a ludicrously huge speaker. He plays a single chord and is physically hurled backwards by the sound (the speaker is destroyed in the process).
• Garage Band: Marty McFly's band, the Pinheads, which auditions for the Battle of the Bands competition.
  Audition Judge: Hold it, fellas. I'm afraid you're just too darn loud.
• Get Back to the Future: This is the plot of the movie, and the Trope Namer. Marty is stranded without plutonium in 1955 and needs to harness lightning in order to get home.
• George Lucas Altered Version: Initially, this was released as a stand-alone film, and the ending was just a case of And the Adventure Continues. The "To be continued" text was added later in the video releases before being removed on the DVD release.
• Given Name Reveal: One of the black musicians, the one who cut his hand by accident, is named Marvin. No big deal. But when we discover that his full name is Marvin Berry, and that he's talking in the phone with his cousin Chuck Berry, then suddenly he is a big deal.
• Glasses Pull:
  • At the beginning of the movie, Marty McFly has one after he is blown across the room after plugging his guitar into a giant amplifier at full volume. He sits up in the rubble he has caused, slowly reaches to remove his shades and utters, while staring at the now destroyed amp, "Whoa. Rock 'n' roll."
  • At the very end of the movie, Doc tells Marty "Roads? Where we're going we don't need (glasses flip) roads!" Played with, in that they're his rearview display, predating actual back-up cameras by 15-20 years.
• Gone Horribly Right: Zig-zagged with Marty's Fake Danger Gambit to try and set up his parents at the Dance. Marty will fake trying to go too far with Lorraine, who will then be "rescued" by the heroic George and win her heart. However, it then becomes a legimtiate attempted rape when they're attacked by a drunken Biff and his gang (though it's worth noting the plan was already going off the rails because Lorraine was more eager than Marty). Marty ends up incapacitated and now George has to rescue Lorraine from her would-be rapist for real. However, in a rare subversion, this ironically ends up working far more effectively than the original plan would have. George is able to finally best Biff and genuinely wins Lorraine over (or at least puts him within striking distance for their kiss minutes later).
• Gosh Dang It to Heck!:
  • Zigzagged with Biff, who at first uses a lot of lame insults, like "Butthead". It's averted in a few scenes, like when Biff chases Marty through Hill Valley in Part 1:
    [Biff and his cronies look forwards, there is a manure truck in front of them]
    Biff and Co.: SHIIIIIIIIIIT!
    [crashes into the truck and manure falls into the convertible]
  • In a later scene, Biff tells Marty he's going to take the cost of it "outta your ass".
• Grandfather Paradox: Marty accidentally creates one not by killing his own grandfather, but by taking his father's place as his mother's object of affection. His objective in the film is to direct his mother's attention over to his father in order to save himself and his siblings from non-existence.
• Grievous Bottley Harm: During the skateboard chase, Biff's cronies throw bottles at Marty.
• Grumpy Old Man: Sam Baines really isn't that happy with Marty jumping in front of his car. A younger version of one since he's only 45 but acts like a Grumpy Old Man all the same.
• Hair of Gold, Heart of Gold: Doc Brown was a blond in the past, before he turned into a Silver Fox.
• Hands Looking Wrong: When time-displaced Marty starts getting erased from existence, he holds up his hand to his face and sees it fading in and out.
• Harmless Electrocution: In the climax of the movie, Doc Brown is attempting to connect the power cords needed so that the lightning bolt that's about to hit the clock tower can be used to power the flux capacitor and send Marty back to the future. He takes too long doing this and has just connected the plugs when the bolt strikes, resulting in it (partially) being channeled through him, but he comes out of it none the worse for wear. (The vast majority of the tens of thousands of volts went through the less-resistant electrical connection, which is why he's unharmed.)
• Harsher in Hindsight: In-Universe. 1955 Doc is very happy to discover that someday he will have the chance to travel to the future. Marty is very troubled when he said that: as far as he knows, the terrorists killed him in the initial sequence, and never had the chance to actually use the machine himself.
• Hazmat Suit: Marty dons a radiation suit to handle the plutonium fuel for the DeLorean, and wears it during his trip into the past.
• Headdesk: At the climax, when the Delorean won't start, Marty headbutts the steering wheel in frustration and the engine roars to life.
• Here We Go Again!: The ending was supposed to be this trope as they'd never planned any sequels. The film's main problem (that Marty accidentally erased himself from history while stuck in 1955) resulted because he used the DeLorean Time Machine; just when the problem is solved and everything is perfect, Doc arrives and whisks them off in it again with Jennifer in tow.
• Heroic Resolve: George, when Biff shoves Lorraine down to the ground, gains the guts to send his fist into his bully's face, knocking the jerk out in one punch.
• Heroic Sacrifice: Doc draws the Libyans' attention to give Marty time to run, and gets shot for it.
• Hero Stole My Bike: Marty borrows the base of a kid's makeshift scooter, which he uses as an improvised skateboard during the Chase Scene. He returns the board afterwards.
• High-School Sweethearts: Lorraine states that she knew she would spend the rest of her life with George McFly after they kissed at the High-School Dance. Depending which timeline you're using, this is one week or less after she met him. There may be a slight subversion, though, as in the original timeline, the marriage was less than perfect.
• Historical In-Joke: Of course there are a few. The movie was trying to be a little more timeless, but it still includes references to the mid-80s, like noting that Reagan was known as an actor, rather than a politician, and making it a point to note price and cultural differences between 1955 and 1985 (Gimme a Tab, how about a Pepsi Free.).
• Homework Slave: When we first see George McFly in 1985, his boss (and Schoolyard Bully All Grown Up) Biff Tannen is ordering him to make Biff's paperwork so Biff can present it to their boss (and look good to get a promotion). When Marty McFly goes back in time to 1955, he encounters George and Biff when they were teenagers and Biff is bullying George to make his homework.
• Honking Arriving Car: Early in the film, Marty and Jennifer are suddenly interrupted pre-kiss by a honking horn and a male voice shouting, "Jennifer!" Jennifer acknowledges her dad has shown up to give her a ride home.
• Hope Spot: Twice over with the same issue in the climax:
  • After his "Eureka!" Moment of setting the DeLorean's time circuits to give him a ten-minute head start to prevent Doc's shooting, Marty starts doing a final checking over of the DeLorean before he speeds off to the clocktower... and no sooner does he mention that the engine is running, it conks out.
  • Once back in 1985, Marty attempts to gun it towards the mall, only for the DeLorean's engine to give out once again. However, what makes things all the more dire this time is that no sooner does Marty try forcing the car to start, the Libyans' van speeds past him.
• Hypocritical Humor:
  • When Marty goes over the plan with his father-to-be George to court Lorraine at the Enchantment Under The Sea dance while George is doing laundry, Marty mentions that he will "take advantage" of Lorraine to make her angry at him and George, holding a bra, asks him "Do you mean you're going to touch on her...?" Marty exclaims "no" and then grabs the bra and throws it on the ground.
  • Compare Biff's repeated "Don't be so gullible, McFly" prank to Marty's "Whoa, whoa, Biff, what's that?" tactic in the diner. It must be a generational thing as Biff's grandson seems to have wised up to the misdirection.
• "I Know What We Can Do" Cut: Marvin Berry declaring that the school dance is officially over — unless Marty "knows someone who can play a guitar?" Cut to Marty on-stage.
• Idiot Ball:
  • Doc and Marty have just reloaded the DeLorean time machine's plutonium chamber. Doc prepares to time travel 25 years into the future, but he sees the terrorists' van approaching. Instead of getting in the DeLorean, Doc goes for his unworkable pistol, and this gives the terrorists enough time to drive up and kill him. Marty escapes to 1955 in the time machine, and ends up nearly erasing himself from existence.
  • After Doc tears up the letter warning him about the Libyans killing him, Marty realizes that since he has a time machine, he can go back early and warn him. Instead of going back an hour early to give himself ample time to warn Doc, Marty only gives himself ten minutes, severely limiting his ability to warn Doc in time. Even if he could get to the mall in time, he's really cutting it close.
• I'm Mr. [Future Pop Culture Reference]:
  • Lorraine thinks Marty's name is "Calvin Klein" as "it's written all over [his] underwear". Marty says his name is Marty, but Lorraine (and Biff, if Part II is anything to go by), thinks his name is "Calvin Marty Klein".
  • "My name is Darth Vader! I am an extra-terrestrial from planet Vulcan!"
• Imperial Stormtrooper Marksmanship Academy: The Libyans just barely manage to hit Doc Brown. Then they completely fail to hit Marty. Justified in that they're random, poorly funded guys in a VW microbus, the guy is firing a fully automatic weapon, and he's firing a fully automatic weapon from out the sunroof of a speeding VW microbus.
• Implausible Synchrony: Invoked in the opening scene. Doc's house is full of hundreds of different alarm clocks that he has painstakingly synchronized to all go off exactly 20 minutes late. Every single one of them.
• Improvised Lightning Rod: Doc Brown uses the Clock Tower as a lightning rod to gain the 1.21 gigawatts of electricity the DeLorean needs to get back to the future.
• Improvised Zipline: Doc Brown uses the heavy-duty electrical cable attached to the clock tower as a line to reach the ground quickly and fix a break in the line.
• I Need a Freaking Drink: When Marty is parked with Lorraine and she seems much more receptive to the idea than he initially assumed she pulls out a flask of booze she swiped from her mother's liquor cabinet, causing Marty to take it from her and admonish her for drinking. When she expresses confusion and annoyance about this, further complicating Marty's plans, he takes a look at the flask and shrugs before taking a swig from it himself.
• In Spite of a Nail: Played with. The new 1985 is identical in most respects... but not entirely. The McFly family turned out differently, Biff Tannen turned out differently, Hill Valley's shopping is now done at the Lone Pine Mall, and of course, Chuck Berry got the idea for "Johnny B. Goode" from a sample he overheard during a telephone call from his cousin Marvin.
• Informed Poverty: The McFlys at the beginning of the movie are depicted as poor losers. In actuality, their lifestyle is relatively luxurious. Tellingly, in the improved timeline where they're better off, they still live in the exact same house as in the original timeline, albeit with fancier furnishings and cars.
• Insecure Protagonist, Arrogant Antagonist: The filmmakers describe Marty McFly as a Supporting Protagonist to his future father George in 1955, as Marty teaches the extremely weak-willed George to stand up to Biff Tannen.
• Intergenerational Friendship: This film establishes the relationship between Doc and Marty, a friendship that has truly withstood the test of time. They even provide the trope image.
• Ironic Echo: In 1985, Marty tells Doc that "You don't just walk into a store and-and buy plutonium!" Then in 1955, Doc tells Marty "I'm sure in 1985 plutonium is in every corner drug store, but in 1955, it's a little hard to come by!"
• I Should Write a Book About This:
  • And indeed, George does, based on "Darth Vader from the planet Vulcan" visiting him at night in 1955. One hopes that Gene Roddenberry and George Lucas didn't sue (or possibly George specifically avoided using his 'alien' tormentor's real name]] out of fear).
  • In the novelization, while Marty visits Doc after visiting George's house for the first time, Doc remarks, "If you get back, maybe you could make a movie out of this."
• It Will Never Catch On: Every other minute.
  • In-universe, teen George and Lorraine don't think they'll end up together, and both George and Marty fear the public won't like their art (science fiction writing and Marty's band's rock music, respectively).
  • Marty's would-be grandfather thinks he's an idiot and tells Lorraine that if she ever has a child like him, he will disown her.
  • Doc Brown in 1955 on the idea of Ronald Reagan as President in 1985: "Ronald Reagan? The actor? Then who's Vice-President? Jerry Lewis?" He comes around to it when he sees Marty's "portable television studio" (read: a camcorder), realizing that the President has to look good on TV.
  • Diner owner Lou on janitor Goldie Wilson's aspirations to run for mayor: "A colored mayor? That'll be the day."
  • When Marty says that his family owns two TV sets, Lorraine's mom says that he's joking because nobody does.^note In 1955 a television set cost as much as a used car does today, and most homes did not own multiple television sets until the late-1960s, when many households bought their first color TV and the old black-and-white set ("the spare") was then relegated to another room.
• It Works Better with Bullets: Doc's Colt Single Action Army revolver doesn't fire because he didn't load it.
• I Want My Jet Pack: Parodied. The 1955 Doc thinks 1985 will feature everyone wearing radiation suits due to "the atomic wars" and that plutonium will be "available in every corner drug store." He's clearly imagining 1985 as the Zeerust future that people thought they were headed for in the 1950s. Ironically, the sequel would later recreate this trope for a new generation, what with its portrayal of the then-future year of 2015.
• I Was Never Here: George has changed his mind, and asks Marty for help to date Lorraine. What made him change his mind? A visit from Darth Vader hailing from the Planet Vulcan! Marty suggests he keep this particular turn of events to himself.
  Marty: Let's just keep this brain melting stuff to ourselves, OK?
  George: Oh, yeah, yeah...
• Jerkass: Sam Baines, Marty's future grandfather, has hints of being this. He is more interested in setting up a new TV set than eating dinner with the rest of the family (though he does join them with the TV once he gets it going). He also calls Marty an idiot behind his back despite having only just met him, and warns Lorraine he'll disown her if she has a kid who acts like that.
• Jerkass Has a Point: As painful as it is to admit a jerk like him is right, Biff isn't wrong for saying George's insurance should cover the damages to George's car. After all, George did give Biff permission and it does kind of fall on George that he allowed someone as careless as Biff to use his car^note This was more relevant in 1985. Today, most car insurance plans have elements that specifically cover the driver even when they are driving someone else's car (with permission, that is), so it would be on Biff even if it was George's car; it's still relevant that Biff would browbeat George into taking the hit himself, so that Biff's own insurance rates wouldn't go up.
• Jock Dad, Nerd Son: Inverted. Marty is a cool guy who rides a skateboard and plays guitar, while his dad George is an awkward nerd who gets bullied by Biff and is obsessed with science fiction.
• Just in Time: Doc is able to connect the wire for the lightning strike at the last second.
• The Key Is Behind the Lock: Marty gets locked in a car trunk, along with the keys to the trunk.
• Key Under the Doormat: Doc Brown is not particularly security conscious.
• "Kick Me" Prank: George is the victim of one at school. His classmates enthusiastically obey the sign until an unimpressed Strickland rips it from his back.
• Knight in Shining Armor: Marty tries to set this up as a scam, but Biff interferes and George has to step up for real. Note his white coat. He's her White Knight.
• Lactose over Liquor: George is about to approach Lorraine at the Malt Shop. He needs Liquid Courage and heads over to the bar to order a milk... chocolate.
• Large Ham: Christopher Lloyd chews the scenery with over the top faces and weird expressions.
• Last-Second Joke Problem: The ending was supposed to be this trope, with Doc suddenly showing up to whisk Marty and Jennifer off to the future to sort out their own kids. However, when the film's unexpected success merited a sequel, this bit was retroactively turned into a straight Sequel Hook.
• Late for School: Marty, for the fourth time in a row. He even says, "Damn! I'm late for school!", before hanging up on Doc. He still gets caught by Strickland.
• Leave No Witnesses: After the Lybians shoot Doc for stealing their plutonium, they turn their attention to Marty who saw the act so that he can't say anything. This is what leads to the chase scene that results in Marty's Emergency Temporal Shift.
• Let's Get Dangerous!: Bumbling fretful Doc, when he sees that he accidentally unplugged the other end of the cable, sucks it up, and ziplines off the clock tower in the middle of a storm.
• Letting the Air out of the Band: Happens the minute Biff angrily marches in to throw George out of the diner. Apparently, someone in the room had a good sense of dramatic tension to unplug the jukebox at that exact moment.
• Lightning Can Do Anything: Doc and Marty use a lightning bolt to power the time machine in the DeLorean.
• Like Parent, Like Spouse: Lorraine's father Sam is just as obsessed with TV as her husband George is in 1985. The exact same episode, even!
• Little "No": Marty has a barely audible one as he cries over Doc's "death" at the end of the movie.
• A Little Something We Call "Rock and Roll":
  • In one of the most famous examples of the trope, Marty impresses the 1955 Hill Valley high school with a performance of 1958 Johnny B. Goode, and implicitly inspires Chuck Berry himself to write it. The audience is not thrilled by his metal-like guitar solo at the end, though.
    Marty: I guess you guys aren't ready for that yet...but your kids are gonna love it.
  • An earlier involuntary example occurs when Marty "invents" the skateboard to humiliate Biff and his gang.
  • Marty uses references to Star Wars and Star Trek (as well as The Outer Limits (1963) and The Twilight Zone (1959) in the extended cut) to scare George into attending the dance with Lorraine. While he finds the experience terrifying, it does inspire him to write a science-fiction novel in the future.
• Living Prop: Dave and Linda basically only exist so that the photo Marty has can visually show the ripple effect results of Lorraine and George never getting together, without actually affecting Marty (until the end at least).
• Look Behind You: After Marty trips Biff in Lou's Cafe, Biff is about to punch his lights out when Marty nonchalantly points over Biff's shoulder and says, "Whoa, whoa, Biff... what's that?" Biff turns to look, and when he turns back, Marty punches him in the face and runs for it.
• Luke, You Are My Father: Marty knows past George and Lorraine are his parents, but he does his best not to tell them since telling them would change his future. There are a couple of instances where he accidentally refers to them as his parents before he backpedals and calls them by their names.
• Malt Shop: Lou's Diner.
• Mama's Baby, Papa's Maybe: Discussed. When Marty and Doc watch George being literally kicked around in the hallway, Doc suggests that Marty was adopted.
• Man Hug: After Doc Brown assures Marty that everything will be alright, he rushes upon him with a hug that left the Doc wondering how much it actually meant for him^note Also, men were not quite so open with their emotions in 1955; Doc is taken aback, but seems to realize that it's another difference wrought by the passage of 30 years.
• Manly Tears: Marty towards the end of the movie. After seeing his friend, Doc, killed once, Marty is now praying that Doc read his letter and took precautions so he wouldn't be killed a second time. Marty arrives just in time to see the Libyans shoot Doc again. Running over to him, Marty finds Doc unconscious. Assuming the worst, he begins sobbing. However, we find out that Doc is fine.
• Massive Numbered Siblings: There are five Baines siblings by 1955, possibly at least one more since Stella is pregnant.
• Mass "Oh, Crap!": Biff and his gang just before crashing into the manure truck: "SHIIIIIIIIIIIIIIIIIIIIIIIIIIIIT!!!"
• Meaningful Background Event: When Marty tries to tell Doc about the terrorists, Doc objects by saying no man should know too much about his own future. When he says, "We've already agreed..." over his right shoulder is a man riding a bike, wearing a white hat, his future self from the second movie.
• Meaningful Echo: Two exchanges, thirty years apart, show that things between George and Biff have always been the same.
  • In 1985, George and Biff's conversation after Biff wrecks a car George loaned him:
    Biff: Hey, did you finish up my reports?
    George: Well, I figured, since they weren't due 'till Monday...
    Biff: [playing George's head like a bongo] Hello? Helloooooo?! Anybody home?! Huh?! Think, McFly! Think! I've gotta have time to get 'em retyped. Do you realize what would happen if I hand in my reports in your handwriting? I'll get fired. You wouldn't want that to happen, would ya?
    [George hesitates; Biff pulls on George's tie]
    Biff: Would ya?
    George: Well no, of course not, Biff. I wouldn't want that to happen. [Biff helps himself to some gumballs] Now look, I'll uh, finish those reports on up tonight, and I'll run 'em on over first thing tomorrow. All right?
    Biff: Not too early. I sleep in Saturday. [gestures downward] Oh, McFly, your shoe's untied.
    [George looks down, Biff taps George's nose]
    Biff: Don't be so gullible, McFly...
  • Marty walks into Lou's Diner in 1955 and after Lou hands him a cup of coffee, the camera pans to show that Marty is sitting next to George, who is occupied eating his breakfast. Suddenly the doors fly open:
    Biff: Hey, did you finish up my homework?
    George: Well, I figured, since it wasn't due 'till Monday...
    Biff: [again with the head-battering] Hello? Helloooooo?! Anybody home?! Hey! Think, McFly! Think! I gotta have time to recopy it. Do you realize what would happen if I hand in my homework in your handwriting? I'll get kicked out of school. You wouldn't want that to happen, would ya?
    [George hesitates; Biff grabs George by his shirt]
    Biff: Would ya?
    George : Well no, of course not, Biff, I wouldn't want that to happen... I'll, uh, finish that on up tonight and then I'll, uh, bring it over first thing tomorrow morning.
    Biff: Not too early. I sleep in Sunday. [gestures downward] Oh, McFly, your shoe's untied.
    [George looks down, Biff taps George's nose]
    Biff: Don't be so gullible, McFly...
• Meet Cute: George and Lorraine's first meeting, the way it originally happened.
• Men Act, Women Are: Marty's original plan to get his parents together is built on the expectations of this trope, i.e. Marty and George acting with Lorraine being a passive "nice girl." It's subverted when Lorraine is the one to act while Marty is passive, which is the exact opposite of what needs to happen to make the plan work. But later, Biff gets involved and the trope is played straight. Thus, it's ultimately a Double Subversion.
• Mighty Whitey: Marty travels back to the mid-1950s, where he introduces Rock & Roll to the world... a musical style that had been developing over the course of the previous decade, primarily by African American performers, via Blues and R&B.
• Mistaken for Aliens: Upon his arrival in 1955, Marty is mistaken for a space alien, something he later takes advantage of in order to convince George to ask Lorraine out. In fact, the filmmakers specifically chose to use a DeLorean as the time machine because its gull-wing doors would help sell the idea that it could be mistaken for a UFO in the 1950s. This trope's inclusion was also the inspiration for Sid Sheinberg's infamous suggestion that the film be retitled Spaceman from Pluto. You'll notice that in the final film, the Tales from Space comic book includes a mention of "Space Zombies from Pluto."
• "Mister Sandman" Sequence: The trope is named for the scene in the movie when Marty McFly enters Hill Valley in 1955 to find that the town square is completely decked out to reflect The '50s. The period song "Mister Sandman", as performed by the Four Aces, plays over this scene.
• Model Planning: Doc builds an elaborate model of city blocks to demonstrate his plan to Marty, then apologizes for "the crudity of the model". It also catches on fire during the Disastrous Demonstration.
• Moment of Awesome: In-universe. For the 1955 teenagers (who had never seen films with action sequences, or perhaps any action in the all-peaceful Hill Valley), the way Marty eludes the bullies and gets Biff to crash into a manure truck is the most awesome thing ever seen. Lorraine is more in love than ever with Marty after witnessing that.
• Mugging the Monster: Biff's pals threaten Reginald with a racial slur; then Marvin and Reginald's three friends appear. Oh, Crap!...
• Mundane Made Awesome:
  • George's method of ordering a milk... chocolate. The outtake is even better, where the milkshake glass bounces off George's hand and crashes to the floor.
  • Marty's skateboarding antics to get away from Biff and his gang aren't really fantastic. He skates away from them, then grabs a truck's tailgate to get away from them. The music sells it though. It's not until he jumps off the board, runs over Biff's car, and jumps back onto the board that it really earns the music.
• My Car Hates Me:
  • The Libyans' VW bus, which refuses to start at the same time their Kalashnikov rifle jams.
    Libyan Gunner: Rrrgh! Damn Soviet gun!
    Libyan Driver: Gah! Damn German car!
  • And of course, the DeLorean, which breaks down after Marty arrives in 1955, just before he is about to return to 1985, and just after he does return and needs to get to the mall to save Doc from the Libyans.
• Nature vs. Technology: Discussed by Doc Brown, as an advocate of Science Is Good, he cannot understand why Old Man Peabody wanted to grow pine trees on what was Twin Pines Mall's location. Later, he and Marty exploit nature's gift of a lightning strike's known time and date in order to power the time machine so it can get back to the future.
• Naughty Birdwatching: When George is spying on Lorraine in 1955. Lorraine in the original 1985 even assumes that George actually was birdwatching, which George doesn't deny.
• Naughty Under the Table: Marty's future mother squeezes his thigh under the table, causing him to jump up from the table and RUN out the door.
• Newspaper Backstory: The opening scene pans over a bunch of clocks and a cork-board. Pinned onto the board are two news articles, which hint at Doc Brown's life before the film takes place.
• Newspaper Dating: While Marty is staring around in bemusement at the 1955 version of his hometown, a man nearby drops a newspaper into a trash can. Marty retrieves it to confirm that he's in the past and learn the exact date.
• Nice Job Breaking It, Hero: Marty pushes George out of the way of being hit by the car, which keeps his parents from meeting (he himself had to fix that) and he and his siblings almost getting erased from existence.
• Nice Job Fixing It, Villain:
  • Marty's plan to force himself on Lorraine is a terrible one. Marty can't really bring himself to abuse Lorraine, and she is in fact eager to make out with him, so George couldn't have acted as a savior (Lorraine, at least until she somehow picks up an incest squick from kissing Marty, probably would have told George to get lost). It's only after Biff shows up and takes Marty's place that it becomes a Damsel in Distress scenario.
  • Biff pushing Lorraine down and laughing about it gives George the resolve he needs to punch him out.
• No Accounting for Taste: George and Lorraine in the original 1985, at the start of the film. Marty admits to Doc in 1955 that he doesn't understand their relationship at all, as they have nothing in common and his father has always been completely spineless.
  Doc: What are their common interests? What do they like to do together?
  Marty: ...nothing?
• Noodle Incident:
  • Marty setting fire to the living room rug at the age of eight.
  • Also, it's briefly implied that Marty and George McFly aren't the first victims of a Sam Baines hit-and-run accident, given that the moment George flees on his bike, Sam shouts, "Stella! Another one of these damn kids jumped in front of my car! Come on out here and help me bring him in the house!" Which makes one wonder whether Lorraine was well-known for never closing her curtains.
  • A deleted scene has Doc bribe the cop with a "permit" (actually a $50 bill).
    Cop: You're not gonna set anything on fire this time, are you, Doc?
    Doc: [pause] Nah!
  • At no point in the film is it answered as to why Doc has a giant speaker amplifier in his house!
• Nostalgia Ain't Like It Used to Be:
  • Downplayed; while the film's portrayal of 1955 is rosier than 1985, the film does a good job in showing both the bright, sunny veneer of The '50s and the darker, less pleasant aspects underneath, without being totally blinded by rose-tinted glasses.
  • When Marty arrives in the 1955 town square, we can see some of the things that have and haven't changed since then. The Texaco station has a team of four uniformed men to service cars, including filling the tank and polishing the engine. Also, much like the 1985 town square has a mayoral campaign van going around blaring "Re-elect Mayor Goldie Wilson!" on loudspeakers, the 1955 version of this scene has a car blaring "Re-elect Mayor Red Thomas!" on loudspeakers, even decked out with similar-looking signs and similar "progress is his middle name" slogans.
• Not Hyperbole: At the end of this movie (and the beginning of Part II), when Marty is reunited with Jennifer after being in 1955, she says "Marty, you're acting like you haven't seen me in a week", to which he says "I haven't". For Jennifer, it'd been less than 24 hours since they were together, but for Marty, he really did go a week without seeing her, arriving on November 5, 1955 at 5:00 AM and leaving on November 12, 1955 at 10:04 PM.
• Not Used to Freedom: Marty's uncle "Jailbird Joey" is more comfortable as a toddler confined in his playpen.
  Marty: Better get used to these bars, kid.
• Now You Tell Me: Marty gets Blown Across the Room when he tries to hook up to the amplifier. Then Doc calls and, among other things, warns Marty not to use the amplifier.

Tropes O-Z

• Odd Friendship: Doc is an inventor and scientist in his 60s. His best (and possibly only) friend is a 17 year old boy with little knowledge of or interest in science and technology, except perhaps as it relates to music production.
• Of Course I'm Not a Virgin: Lorraine tells Marty, "I'm almost eighteen years old! It's not like I've never parked before!"
• Oh, Crap!:
  • Marty after Doc tells him his clocks are twenty-five minutes slow, making him realize he's late for school again.
  • "Oh, my God. They found me. I don't know how, but they found me. Run for it, Marty!"
    Marty: HOLY SHIT!
  • Marty goes wide-eyed after tripping Biff up in the diner, seeing how much bigger Biff is than himself.
  • The look on Doc's face◊ when his return home simulation causes some rags to catch fire is utterly priceless.
  • Doc Brown's expression when he realizes Marty is being truthful about being from the future doubles as an Explain, Explain... Oh, Crap!.
  • Doc has two moments following those. First when he learns that the time machine requires 1.21 gigawatts to work, going into a Heroic BSoD about how careless he was when designing it. The only thing that pulls him out of it is when Marty has a "Eureka!" Moment that they can harness a bolt of lightning to generate enough energy to power the flux capacitor. The second is when he learns that Marty interfered in the first meeting between his parents, which has started to erase Marty's siblings from existence.
  • Marty, when Biff, not George, pulls him out of the car on the night of the dance.
  • The look on George's face when he discovers it is Biff, not "Calvin", in the car with Lorraine.
  • Biff's thugs when the rest of Reginald's bandmates get out of the car in the trunk of which they just dumped Marty on the night of the dance.
  • Biff, when he sees in George's face that he's pushed him too far and a left hand is coming his way.
  • Marty gets a huge one at the dance when he starts to fade out of the photograph and sees his right hand start to fade away.
  • Marty when the Libyans bring out the RPG. This is what prompts him to attempt driving at 90mph, causing him to activate the flux capacitor and travel back in time.
  • Doc loses his shit multiple times when he's climbing the clocktower, as the situation just gets worse and worse.
• Older Than They Look: According to Word of God, Old Man Peabody who owns Twin Pines Ranch is 45 years old, despite the fact that he looks thirty years older. Actor Will Hare was in his late sixties at the time of filming.invoked
• Ominous Message from the Future: Marty repeatedly tries to warn Doc that he will be shot by terrorists in 1985 when Marty goes back in time, but Doc refuses to hear it, fearing consequences to the timeline. Marty eventually opts to write him a sealed letter to open in 1985. Doc found the letter prematurely, and while he initially tore it up, he eventually decided "what the hell" and taped it back together. Heeding the warning, Doc wore a bullet proof vest when he was shot, surviving the encounter.
• One-Hit KO: In his defense of Lorraine, George lands just one punch on Biff. As it turns out, that one punch was all he needed.
• The Oner: The opening shot of the film (an Establishing Shot of Doc Brown's laboratory, which sets up a few plot points and Foreshadowing) goes on for several minutes. It's a quite complicated shot, requiring a lot of technical coordination, even though no actual actors appear onscreen.
• O.O.C. Is Serious Business: Doc is surprised and asks for confirmation when Marty mentions that George stood up to Biff, for the first time ever. This is a subtle hint about Doc realizing that the status quo timeline has already been deeply changed, but without serious consequences (Marty and his siblings are going to be born despite the changes) so reading Marty's letter would now be less of a game-breaker for him.
• Our Time Machine Is Different: The film's creators justify this by saying that it makes more sense to have a time machine that you can take with you, rather than one that just sits at your destination. Plus the stainless steel construction makes the flux dispersal work that much better.
• Parallel Porn Titles: In the 1985 town square, the Essex Theater is showing a porno called Orgy American Style, which parodies the title of the old TV series Love, American Style. Incidentally, a film by that title actually was made in 1973, although comments from Bob Gale suggest that the Back to the Future filmmakers were unaware of this fact.
• Parental Bonus: After Marty wakes up from being hit by Lorraine's father's car, Lorraine tells him that his pants are "over there... on [her] hope chest". Many people who were born after the 1950s may not understand what a hope chest is. It's a chest that young girls used to keep in preparation for their marriage. In other words, Lorraine is already fantasizing about marrying the young man that she does not realize is her future son. One assumes that in the original timeline, this also happened with George.
• Parental Hypocrisy: Lorraine scoffs at Marty for parking with his girlfriend Jennifer, saying "When I Was Your Age... I never chased a boy, or called a boy, or sat in a parked car with a boy". Marty is shocked when he travels back in time and finds that his mother is actually willing to "park for a while" (plus smoking and drinking) although it wouldn't be so bad if she did it with him.
• Parental Incest: Parodied, in that whilst Marty knows who Lorraine really is, she has no idea as to his true identity. Marty seriously invoked tries to avert this trope, and does everything wrong until the night of the dance; everything he does only makes him more attractive to her. He jumps and flees when she makes a pass at him, defends her from Biff's "meat hooks", trips up Biff when Biff goes after George and leads Biff on an over-the-top skateboard chase culminating in Biff's comeuppance in manure. By this time, she really wants to get to know him. Luckily, she ends up feeling the same way as Marty, equating the experience to "kissing my own brother" (in the novelization, it's instead "kissing my father").
• Pastiche: This movie is one of the biggest of the 80s massive nostalgia wave for the mid 1950s, alongside A Christmas Story.
• Pedal-to-the-Metal Shot: In the "race-against-the-lightning" climax...primarily to demonstrate Marty's desperation when the car won't start right away. Also the "aggressively shifting gears" variant several times during the car chase with the Libyans, which actually plays a critical role in stranding Marty in 1955 in the first place (the "time circuits on" lever is close enough to the gear shift Marty accidentally bumps it).
• Percussive Maintenance: The engine of the DeLorean stalls at nearly the exact moment before Marty has to start accelerating to go back to the future. As he struggles to start the car again, we see him becoming increasingly frustrated at his lack of success before his frustration gets the better of him and he headbutts the steering wheel, leading the DeLorean to start up again.
• Pet's Homage Name: Doc's dogs. His 1985 dog is named Einstein, his 1955 dog is Copernicus.^note A subtle hint at how Doc's thinking advances; in the '50s, he pays homage to the man who developed the heliocentric model of the solar system. In the '80s, he references the man who developed the far more advanced theory of special and general relativity.
• Playing Possum: In the new timeline, Doc Brown fakes his death after being gunned down by the Libyans. He survives thanks to a Bulletproof Vest, to Marty's pleasant surprise.
• Plot-Based Voice Cancellation: When Marty tries to tell Doc about the future while the latter is on top of the clock tower:
  Marty: [shouting up at Doc] On the night I go back, you will get—
  [The clock strikes ten, drowning out Marty and startling Doc]
• Police Are Useless:
  • Aside from Attempted Rape (though to be fair, the film doesn't imply that anyone ever called the cops about it) above, Biff in 1955 also makes multiple threats of assault throughout the movie, and in one scene attempts to commit murder, and nobody even seems to think that he's doing anything illegal. Some of this is slightly justified by bullying not being taken anywhere near as seriously in the 50s as it is today.
  • The one time a cop is shown on screen, he's doing nothing more than inquiring about the Doc's little "weather experiment" and whether the Doc has a permit. Doc bribes him to look the other way while handing him some money. A deleted scene shows him doing this up close.
  • No officers turn up to investigate the shootings at the Mall, or the car crash into the movie theater when Marty returns to 1985. The novel does mention sirens in the distance though as Doc and Marty leave the Mall to retrieve the DeLorean.
• The Power of Rock: Played with. Marty's rendition of "Johnny B. Goode" impresses everybody — until he gets carried away with his guitar solo.
  Marty: I guess you guys aren't ready for that yet... but your kids are gonna love it.
• The Precarious Ledge: Doc has to balance on a ledge up on the clock tower. It breaks and sends him hanging from the clock hand.
• Precision F-Strike:
  • "If my calculations are correct, when this baby hits eighty-eight miles per hour... you're gonna see some serious shit."
  • When Biff and his gang are about to crash into the manure truck, they all yell "SHIIIIIIIIIIIIIIIIIIIIIIIIIIIIT!!!"
  • Enforced by Marty when he's explaining to George the plan to "save" Lorraine from being molested by Marty.
    George: Do you really think I should swear?
    Marty: Yes, definitely! Goddammit, George, swear!
• Prime Timeline: Though it doesn't really take place in a Multiverse, BttF does have a central timeline which Doc and Marty are trying to protect.
• "Psycho" Strings: The musical score gets screechy as Marty fades from existence.
• Punch Catch: Biff does one of these to George and almost breaks his arm.
• Punk in the Trunk: Marty gets thrown and locked into a trunk by Biff's goons.
• Quip to Black: "Roads? Where we're going, we don't need roads." Cue the DeLorean time machine taking flight towards the camera, after which, it smashes to the credits.
• Quizzical Tilt: Einstein tilts his head when the back of Doc's truck opens and the DeLorean makes its entrance.
• Race Against the Clock:
  • Because Marty accidentally interfered with his parents' first meeting, he winds up putting his own existence in jeopardy. He has a week to get George and Lorraine hooked up by the time of the Enchantment Under the Sea dance or he will fade out of existence.
  • Doc Brown and Marty race in spite of setbacks to implement their plan to cross a certain point at the right speed at the very moment a lightning bolt hits.
• Reality Is Unrealistic: Some people complain that Michael J. Fox's singing double is a bit too low for Marty's character during his performance of "Johnny B. Goode". However, it's pretty common in Real Life for somebody's singing voice to sound radically different from their speaking voice — see Singing Voice Dissonance for examples. Also, the song had been recorded before Fox was officially cast.
• "The Reason You Suck" Speech: Strickland really dishes it out to Marty at the beginning for being a "slacker", and to the rest of the McFly family as he drives his point home.
• Reed Richards Is Useless: It's understandable that Doc wouldn't want time travel technology spreading, but if he patented that nuclear reactor with 1.21-gigawatt output that's small enough to fit in the back of a car, he'd easily become a millionaire and probably revolutionize the global energy market.
• Relatively Flimsy Excuse: Marty McFly introduces Doc Brown to his teenage mother as his "uncle".
• Reliably Unreliable Guns: Marty is saved repeatedly from being shot by Libyans because of their rifle jamming. They are shooting an AK-47, which are famed for their reliability even under the harshest conditions. However, we do see them simply trying to clear the jam rather than abandoning the gun immediately. Eventually the terrorist does clear the jam and continues firing. You can also overhear them complaining about how the gun and car are cheap off-brands, so the idea that they were intentionally sold defective products (like the fake bomb Doc gave them) isn't too farfetched.
• Reports of My Death Were Greatly Exaggerated: Marty believes Doc to be dead after the terrorists riddled him with bullets. While he is mourning, Doc comes back to life behind him. Marty slowly turns his head in disbelief but is overjoyed when he realizes what's going on.
• Rescue Romance: Marty tries to set his parents up by faking a situation where George saves Lorraine from sexual assault (namely, by Marty himself). It goes off the rails when Lorraine is more eager than Marty is, only to be set right when Biff intervenes and genuinely tries to assault Lorraine, and George ends up genuinely saving her by punching Biff out.
• Ret-Gone: Dave, Linda and (almost) Marty in the photograph.
• Retroactive Precognition: Marty has one when he first walks into Lou's, as he recognizes that the busboy is Goldie Wilson, who will be mayor in 30 years. Marty inadvertently blurts out "That's right, he's gonna be mayor!" when Goldie tries to give George a pep talk about standing up to Biff and "being someone", planting the idea in Goldie's mind.
• Rewatch Bonus:
  • In the opening scene, when Marty shows up at Doc's house, all the clocks were showing the time around 7:53. Except one, which was showing the actual time around 8:18, when Marty pushes his skateboard to the side.
  • When Marty tries to use his family photo to convince Doc he's from the future, Doc dismisses it as a forgery, noting that, "They cut off your brother's hair," with a quick glimpse of said photo that suggests at most either a defect in the film or simply that his hair color blended into the background.^note The fact that Marty doesn't so much as offer a "Wait... what?" in response lends credence to the idea that this is a throwaway gag we're meant to dismiss. Those rewatching the film, however, will know exactly what's happening - Dave is already beginning to fade from the picture.
• Rewind, Replay, Repeat: "They found me... I don't know how, but they found me... Run for it, Marty!" replayed by 1955 Doc Brown who was told not to by Future Boy Marty.
• Riddle for the Ages: What does the DeLorean's stainless steel construction do to the flux dispersal? Doc was going to explain before he and Marty hurriedly moved to avoid being hit by the DeLorean as it reappeared.
• Right Place, Right Time, Wrong Reason: Marty finding that George is a peeping tom.
• Ripped from the Phone Book: When Marty is looking up Doc Brown's house in the phonebook, he tears the page out for reference.
• Ripple-Effect-Proof Memory: Marty can remember his own timeline, but he risks erasing himself from existence because of his intervention in the past preventing his parents from hooking up. He eventually manages to create a Close-Enough Timeline in which his parents and siblings are far more successful and assertive, which saves him from disappearing but is tremendously disorienting to him when he first sees it. In the next two movies he treats the "new" timeline as the definitive one, but it could go either way whether the ripple effect caught up with his memory or he just prefers the "new" one to the "old" one.
• Road Apples: The film has Biff Tannen and his gang crash into a truck of manure after a time displaced Marty McFly from 1985 evades them on a makeshift skateboard.
  Biff, 3D, Match and Skinhead: SHIIIIIIIIIIIIIIIIIIIIIIIIIIIIT!!!
• Rube Goldberg Device: The film begins inside Dr. Emmett Brown's Gadgeteer's House, where his alarm clock triggers a machine to automatically prepare breakfast for him and for his dog, Einstein. Since Doc hasn't been home for a few days, his kitchen is a mess of uneaten breakfasts.
• Rule of Cool: Doc reasons that if he was building a time machine out of a car, then it might as well have a bit of style. He does have a more practical reason, though; He mentions the DeLorean's stainless steel body before being cut off by the Delorean's reappearance.
• Running Gag:
  • People mistaking Marty's down jacket as a "life preserver" — Lou, Skinhead (one of Biff's bullies), and Lorraine's mother. In the last case, Marty explains it away as being part of the Coast Guard; Doc later predicts, when using his mind-reading device, that Marty wants him to donate to the Coast Guard.
  • Lorraine keeps calling Marty "Calvin Klein", even after Marty corrects her. She eventually comes to believe his name is "Calvin Marty Klein".
  • Marty and Jennifer getting interrupted whenever they're about to kiss.
• Running Over the Plot: Shortly after arriving in 1955 Marty accidentally gets run over by his grandfather's car, which introduces him to his mother (who is instantly smitten with him) and accidentally prevents his parents from meeting. This triggers the main subplot where Marty must work to get his parents back together to stop the Grandfather Paradox from obliterating him from existence.
• San Dimas Time: Marty laments that he'll be too late to warn Doc of his fate once he gets back to 1985 — until he realizes that he has a time machine, and he has all the time in the world. Unfortunately, he doesn't think to give himself any more than just ten minutes, and the DeLorean's engine is not obliging, so he still doesn't make it in time to save Doc. Fortunately, Doc decided to bend the laws of history and read Marty's letter from 1955 anyway.
• Scale Model Destruction: Doc Brown demonstrates the plan to harness the lightning to get Marty back home - the electricity overcharges the model car and it speeds off the table into a corner and starts a fire. Marty is not exactly reassured.
• Scary Black Man: Played with. Biff's gang isn't afraid of Marvin when he confronts them for messing with his car, but when the rest of the Starlighters pile out, it's a different story. However, Biff's gang seems more afraid of the copious amount of pot smoke billowing out of the Starlighters's car than anything else.
  Skinhead: Look, I don't wanna mess with no reefer addicts, okay?^note Of course, this was the era when marijuana smokers were made out to be dangerous psychotics.
• Screw Destiny: Inverted. Doc originally is very vocal about not finding out too much about one's own destiny, believing that subverting destiny could be potentially world-destroying, but eventually gives in and tapes Marty's letter back together, learning of his murder in 1985 and thus being able to prevent it.
• Self-Plagiarism: George's line to start out his Big Damn Heroes moment ("Hey you, take your damn hands off her") is a variation of what Larry says when he's rescuing Grace ("Take your goddamn hands off her") in Robert Zemeckis' first movie, I Wanna Hold Your Hand. A lightning strike is also important to the plot of the earlier movie, as is a fateful encounter with a legendary rock & roll star.
• Sequel Hook: Unintentional, made into one by Executive Meddling. The creators swore that Doc's line that "something's gotta be done about [Marty and Jennifer's] kids" was a joke.
• Set Right What Once Went Wrong: Marty accidentally travels back in time 30 years, and has to enlist the help of that time's Doc Brown in order to get back home. However, before meeting him and explaining himself, he alters the event that made his parents meet and fall in love; his father remains a social outcast while his mother develops attraction towards him. Marty's eventual solution to this problem has the unexpected bonus of his father being more confident and assertive over Biff in 1985, leading to this trope in a roundabout way.
• Sham Supernatural: Marty uses his radiation suit and Walkman stereo to dress up as "Darth Vader" from "the Planet Vulcan". He frightens George and threatens to melt his brain if he doesn't take Lorraine to the school dance.
• Shared Family Quirks: Marty sits in Lou's and nervously rubs the back of his head, and the camera pans to show he's sitting next to George, who is doing the exact same thing. They both even do a synchronized head-turn at the sound of Biff entering.
• Shipper with an Agenda: Marty tries actively to make George and Lorraine hook up; if they don't, he will be RetGone.
• Shouldn't We Be in School Right Now?: The only time Marty is seen at school in 1985 is towards the beginning. First, getting chastised by Mr. Strickland for arriving late and allegedly being a slacker, and afterwards, being rejected from his school's Battle of the Bands competition.
• Shout-Out:
  • The farmer is Old Man Peabody, and his son is named Sherman.
  • In Doc's lab in the beginning, the amplifier is labeled "CRM 114", which was the code name for a radio device from Dr. Strangelove.
  • After Sam Baines hits Marty with the car, he yells "STELLA!".
  • While trying to convince Doc Brown to get him Back to the Future, Marty tells him that "Doc, you're my only hope".
  • In order to convince George to go out with Lorraine, Marty sneaks into his bedroom dressed in the radiation suit and claims to be "Darth Vader", an extra-terrestrial from the planet Vulcan, who will fry his brain (with Eddie Van Halen) if he doesn't ask her out.
  • While playing "Johnny B. Goode", Marty emulates other guitar heroes, duck-walking like Chuck Berry, windmilling like Pete Townshend, and tapping like Eddie Van Halen.
  • The time circuits display the destination time, present time, and last time departed in the colors of red, green, and yellow respectively. This is a reference to those same three colors being used for the time display in the 1960 version of The Time Machine.
  • Doc finds himself hanging from the Tower's Clock, like Harold Lloyd (no relation) in Safety Last!
  • Marty's waking up scene mirrors Dorothy's in The Wizard of Oz.
• Shown Their Work: The DeLorean constantly breaking down is more than simply Rule of Drama. DeLoreans were infamous for being all-style, no-substance. While they're beautifully designed, their engines and other under-the-hood parts were garbage, and they'd often break down for no apparent reason.
• Shut Up, Hannibal!: A downplayed one with the final line of Marty's first scene with Strickland:
  Strickland: No McFly ever amounted to anything in the history of Hill Valley!
  Marty: Yeah? Well, history is gonna change.
• Sliding Scale of Idealism vs. Cynicism: Very idealistic. Even the Darker and Edgier Part II is mainly optimistic overall.
• Slipping into Stink: Marty causes Biff to crash into a manure truck and dump the contents on his convertible.
• Slow Electricity: When the lightning hits the clock, the bolt travels down the cable roughly at walking pace.
• The Slow Path:
  • 1955 Doc regrets having to wait 30 years to talk to Marty about their adventures.
  • Regarding Marty's attempts to warn him of his impending death, Doc insists that he'll find out through the ordinary progression of events.
• Silk Hiding Steel: Lorraine plays the role of the proper, timid 50s girl, but she's a proper predator, pursuing Marty relentlessly and dropping the Kubrick Stare when she's really horny.
• Sounding It Out: Marty sounds out the letter he is writing to Doc about the terrorist attack in 1985.
• Soundtrack Dissonance: "Mr. Sandman" by The Four Aces, a cheerful song, is used to underscore Marty's confusion as he arrives in the 1955 Hill Valley during the "Mister Sandman" Sequence. Downplayed, as it represents the (apparent) clean, wholesome, optimistic, friendly Fifties Marty found himself in.
• Southpaw Advantage: There is George McFly's famous badassery level up scene where he decks his lifelong Barbaric Bully tormentor Biff Tannen with a big, left-handed haymaker to protect the girl he loves. In an early draft of the script, there was a scene where George discovers that his left arm is for some reason much stronger than his right.
• Speaking Like Totally Teen: Inverted; Marty uses an awkward imitation of '50s-era teenage slang to get out of "trouble" when he accidentally calls his future father "Dad"... "Dad... daddy... daddy-o."
• Spear Carrier: The couple at the dance is amazed at George standing up for himself.
• Spit Take: Marty when seeing Lorraine smoke in the car.
• Springtime for Hitler: Marty's plan to get his parents together is to pretend to attempt to force himself on his mother, than have George rescue her. Things go awry when she turns out to be very eager to *ahem* "get to know" Marty.
• Stable Time Loop:
  • Nearly; Marty's having to instill George with the confidence to pursue Lorraine winds up altering Marty's present-day (but not by too much, because although the family now has a BMW and at least two other cars, they still live underneath the powerlines in a middle-class housing development).
  • In a more fitting example of this trope, Chuck Berry heard Marty playing Johnny B. Goode (except for the intro riff and first verse, which Marty played before Marvin made the call, but presumably Marvin played that part to Chuck at some later date) at the dance thanks to his cousin Marvin's call, and started getting into rock & roll, eventually recording the song himself so that Marty could learn to play it.
• Steel Ear Drums: Averted during the climax as Doc clutches his head and screams in pain as the Hill Valley courthouse clock chimes a couple of yards away from him.
• Stock Clock Hand Hang: The 1955 Doc comes up with a plan to send Marty back to 1985 by channeling the electricity from a lightning strike that's set to hit the clock tower. On the night of the thunderstorm, a bolt strikes a tree branch and disconnects the cables the Doc has set up to capture the lightning. At the last minute, he has to go up onto the clock tower and reconnect the cables. When the platform he's standing on breaks, he grabs onto the clock hands to keep from falling to the ground.
• Stolen Good, Returned Better: Marty McFly steals a kid's scooter, ripping off the handles so it's just the board. When he gives it back, it's the world's first skateboard.
• Stopped Clock: The clock tower stopped after being struck by lightning at 10:04 pm on November 12, 1955, giving Marty and Doc a precise time to use the lightning to get Marty and the DeLorean back to 1985.
• Stopped Dead in Their Tracks: After Marty escapes the Peabody Farm, he drives down the road trying to convince himself that it's all a dream. Then he hits the brakes, screeching to a stop when he notices his neighborhood, Lyon Estates, is nothing but a huge empty undeveloped plot of land.
• Source Music: All songs in the film, with the exception of "The Power of Love", are diegetic. Averted by Silvestri's score proper, which is non-diegetic.
• Sweet and Sour Grapes: Towards the beginning, Marty admires a pickup truck, wondering what it'd be like if he had it. When he comes back from 1955, he discovers he has that truck (or another truck like it).
• Taken During the Ending: The film ends with Doc Brown arriving from the year 2015 to bring Marty and his girlfriend, Jennifer, to the future to aid his children, and the sequel continues where this ending left off.
• Tap on the Head:
  • Marty gets knocked out after being hit by a car and wakes up perfectly fine several hours later. This would be a running gag throughout the series, as each film would have Marty being knocked out by a physical blow and waking up in a room with either his mother or a distant relative standing over him.
  • George knocks Biff out with a punch to the face, though this is depicted somewhat more realistically as the sequel reveals that Biff is only out for a very short time.
• Technology Marches On: Lampshaded In-Universe:
  • First, when Marty dines with his future maternal family in 1955, Lorraine asks whether his family owns a television set, to which Marty says, "Yeah, you know we have two of 'em...", making her younger brother say "Wow, you must be rich!", to which their mother says, "Oh, honey, he's just teasing you. Nobody owns two television sets!"
  • Later, Marty tries to explain his knowledge of an episode of The Honeymooners as having seen it as a rerun. In several non-English dubs of the movie, the word "rerun" doesn't exist (usually because the country concerned had not adopted the policy of re-airing episodes of television shows as of the mid-eighties), so Marty says instead that he saw "The Man from Space" episode of The Honeymooners "on tape".
  • As the 1955 Doc looks at Marty's camcorder, he says, "Now this is truly amazing: A portable television studio. No wonder your president is an actor, he's got to look good on television!"
• Technology Porn:
  • The DeLorean when Doc introduces it.
  • The opening, showing off various gadgets Doc has at home.
• That Was Not a Dream: After Marty is unconscious, he wakes up, saying "I dreamed that I went back in time." Repeated in the sequels.
• Themed Party: The high school dance is the ocean-themed "Enchantment Under the Sea". It's decorated with statues of Neptune, mermaids, and bubble machines.
• They Wasted a Perfectly Good Sandwich: Marty gets a cup of coffee at Lou's because it's the only thing they've got without sugar, but as soon as he's about to drink it, he realizes George just left, so he runs off after him.
• This Is Going to Be Huge: Old Man Peabody thought he could win money planting pines, even if he only had starting money for two. In the present day, his land is a strip mall.
• This Is My Boomstick: Without revealing himself to be a time-traveler, Marty successfully threatens George, using his futuristic technology (a walkman and hair dryer), to ask Lorraine to the dance, while posing as "Darth Vader from Vulcan".
• Thunder Equals Downpour: Averted when the storm just completely stops right after the lightning hits the clocktower. However, it's played straight in the sequels — with the exact same storm.
• Time Skip: After Marty and George come up with the Fake Danger Gambit plan, the film skips ahead three days later to the night of November 12th, the night of the lightning storm/High-School Dance.
• Time Travel: Probably the most famous example in film.
• Title Drop:
  • Doc declares he has to send Marty "...back! To the future!"
  • And again at the end of the movie when Doc comes back from 2015, to pick up Marty and go back to... you know.
• Toyota Tripwire: Subverted. During the Chase Scene at the town square, Marty almost gets hit by an opening car door but is able to get out of its path in time.
• Tricked Out Time: Doc does this by wearing a bullet-proof vest when the Libyan terrorists shoot him. He doesn't tell Marty this until after Marty comes back. The plot of the entire film is a semi-successful attempt to do this, since Mr. Baines still doesn't hit George with the car, but the timing of major events in George and Lorraine's relationship post-dance is otherwise the same (they live in the same house, have the same number of children at the same time with the same basic personalities, and so on).
• Trust Password: Marty tries several that don't work, such as who the President is in 1985^note Doc refuses to believe an actor could be President, and showing him a photo of his family with his sister in a Class of 1984 sweatshirt^note Doc doesn't believe this because, unbeknownst to Marty, Dave's hair has started to disappear, making it look like it's been poorly doctored. What finally works is the story of how Doc got the (currently very fresh) bruise on his head, and the idea for the Flux Capacitor that came from it.
• Turn Out Like His Father: Played with in every possible way. People, especially Strickland, tell Marty he's going to be a loser like his dad, then the past changes and George is not a loser, but Marty is still destined to be a loser, then that future is possibly avoided, presumably letting Marty succeed at a creative pursuit like his dad.
• Unconventional Vehicle Chase: Marty transforms a box scooter into a skateboard which he then uses to escape Biff and his gang who chase after Marty in their car.
• Undressing the Unconscious: 1955 Lorraine removes Marty's pants while he's unconscious in her room, and even thinks his name is Calvin Klein at first because it's "written all over his underwear". He has a minor Naked Freak-Out when he notices it.
  Marty: Where are my pants?!
  Lorraine: Over there... on my hope chest.
• Unflinching Faith in the Brakes: Inverted. Doc Brown has unflinching faith in his time machine's accelerator. If the car doesn't get up to 88 mph before it reaches him and Marty, then they're going to get flattened. As it happens, the time machine blinks out about 20 feet before it hits them.
• Unspoken Plan Guarantee: Marty tries to warn 1955 Doc with a note that he'll be killed by terrorists in 1985, but Doc tells him that it's dangerous to the space-time continuum to do so, and shreds up the note. When Marty returns to 1985, he witnesses Doc getting killed again... or so it seems; Doc then comes out fine and reveals to Marty (and the audience) that he put the note back together and put on a bulletproof vest for the occasion.
• Used Future: The film treats the eighties this way. It gives the fifties a heavy Nostalgia Filter and treats the eighties as dirty, pervy, and dangerous.
• Vanity License Plate: The DeLorean has the tag "OUTATIME". And really crappy screws holding it on the back of the DeLorean, because of its habit of popping off and pirouetting on a corner. When Doc returns to 1985 from the future to pick up Marty and Jennifer, the plate is one of a barcode.
• Verbal Backspace: In the novelization, after his "When this baby hits 88 MPH, you're going to see some serious shit" line, Doc realizes that Marty is filming this and quickly rewords his statement without colloquial language:
  Doc: When a speed of eighty-eight miles an hour is attained, unusual things should begin happening in this phase of temporal experiment number one.
• Waking Up Elsewhere: Marty is hit by a car after saving his father from the crash. When he wakes, he drowsily assumes the past several hours have been a bad dream when he finds himself comforted by his mother, reassuring him he's safe in 1955. The news shocks him awake and leads to a brief freakout as he finds himself in her bedroom.
• Wall Pin of Love: George performs this move in the school corridor. He approaches Lorraine and places his hand on the locker next to her. However, it doesn't work as planned since Lorraine is more interested in Marty.
• Weather Report: Doc mentions the weather report calls for clear skies, but being from the future, Marty knows better.
  Marty: Since when can weather men predict the weather, let alone the future?
• We Don't Need Roads: At the end of the film, Doc travels forward to 2015 and does some pretty major work on the DeLorean, including installing a "hover conversion" that is really more of a "flight conversion".
• What Does She See in Him?: Doc openly wonders what Lorraine ever saw in George; as far as he knows, they have nothing in common. Her explanation in 1985 is that she pitied him, which 1955 Doc corroborates, name-dropping the Florence Nightingale Effect.
• When the Clock Strikes Twelve: The first film has a variation where the time isn't midnight. When Marty accidentally winds up traveling 30 years into the past, the only power source capable of charging the DeLorean to send him back to the future is a lightning bolt, which is normally impossible to predict. Luckily for him, he still has a flyer about a Stopped Clock in the present that was struck by lightning at exactly 10:04pm thirty years ago... or, in other words, a week after Marty arrived.
• Where It All Began: Marty's destination is to get back to where the movie started. We even get to see a scene from the beginning of the movie again at the end.
• With Great Power Comes Great Responsibility: Doc Brown tells Marty that knowing information from the future can drastically alter one's intended decisions and actions. Marty tries to sneak a letter onto him containing the warning about his potential death in 1985, but Brown quickly notices it and rips the letter while also scolding Marty. By the time Marty returns to the future and seemingly reaches too late to save his life, it turns out Brown had repaired the letter and learned the warning in advance, thus preventing his murder by using a Bulletproof Vest.
• Worst Aid: Lorraine's parents carry the unconscious Marty inside, remove his clothes, and tuck him into bed, despite the fact that the worst thing you can do for someone with a potential concussion (prolonged unconsciousness after a hard fall is a definite sign of concussion, and Lorraine tells him he's been unconscious for nine hours) is move them. It's also very dangerous to let a severely concussed person fall asleep. They would have been much better off calling an ambulance to move Marty safely via stretcher to a hospital to determine the extent of his injuries... but then, of course, we'd have a very different movie. Although somewhat mitigated by the fact that far less was known about concussions back in the 1950s, especially by the general public.
• Wrong Genre Savvy: When the Peabody family comes across the DeLorean crashed inside their barn, the son Peabody mistakenly identifies it as an alien spaceship based on a Sci-Fi comic book he has on his possession. Marty emerging from the car's gull-wing door in his radiation suit reinforces this assumption and when Marty finally takes his head cover off, they believe the alien has "mutated into human form" and Old Man Peabody tries shooting him.
• Write Back to the Future: Marty tries to write a letter to Doc to warn him of his death in 1985, including putting another note telling him to not open it until that year. Doc tears it up while proclaiming he can't let it influence the future. He later tapes it back together and reads it.
• You Already Changed the Past: Played with. Marty goes back in time and introduces 1985 concepts to 1955, but the movie implies that he only changes the source of the original idea without majorly altering their progression into the modern day. He didn't invent skateboards but he introduced skateboarding to Hill Valley earlier than would have caught on naturally, and he didn't write "Johnny B. Goode", but hearing his guitar solo inspired Chuck Berry over the phone. Since these things don't actually change the future, it looks like they were always that way. His comment also inspires the busboy Goldie Wilson to go into politics, although Wilson was already mayor in the original timeline, meaning he would have found inspiration elsewhere.
• You Can't Fight Fate: Doc is convinced that any change would be disastrous and shreds Marty's letter. However, when he sees that Marty has made serious changes while also securing his future, he realizes that change is possible, if you're careful.
• You Keep Using That Word: At least from 1955 Doc's point of view, as he thinks that Marty's use of the word "heavy" still applies to weight and measurements — when, from Marty's point of view, he's just using the slang term for something that has a deep, powerful impact, whether philosophical, intellectual, or emotional.
• You Leave Him Alone!: "Her" instead of "him" is used by George, standing up to the school bully Biff Tannen for the first time to keep him from raping Lorraine. While possessing the resolve, he seems to lack the confidence and the physical prowess, at least for a few minutes...until Biff solves the problem by shoving Lorraine to the ground and laughing about it. Cue Unstoppable Rage and a very solid left hook.

---

Marty: Hey, Doc, you'd better back up; we don't have enough road to get up to 88!
Doc Brown: Roads? Where we're going, we don't need roads...