History Film / Alien

* BittersweetEnding: [[spoiler:Not only a rarity for '70s horror movies, but a double whammy in that only Ripley survives and she is the one that no one in the audience expected to survive. Ripley kills the Alien by blowing it out the airlock of the escape shuttle- but is deeply affected by the loss of her friends and crew.]]

* BadBoss: The Company, made even more explicit in the novelization. Not only don't they provide funding to properly maintain the ''Nostromo'', they had advance knowledge of the DistressCall and worked out in advance that it was a warning. Rather than send a fully-prepared research vessel which would not have been allowed to bring a hostile lifeform back to Earth, they arranged for the ''Nostromo'' to 'accidentally' encounter the alien, which would then be 'collected for safe-keeping' by Company representatives.

* ArbitrarySkepticism: Ripley wants to get rid of the FaceHugger carcass, because they already know that the alien creature [[AlienBlood bleeds acid]] and have no clue what will happen after it's dead. Ash counters this by snarking at Ripley that it probably isn't a zombie. The truth is that he's just following his programmed orders to preserve the creature, and presumably the Facehugger's remains, and the crew's been marked expendable so he doesn't care what the corpse might do to them.

** A DVD bonus which shows some bios of the crew which can be seen briefly in the sequel in their entirety reveals a lot of background information about the crew that never comes up (for example, the Nostromo was Lambert's first posting after graduation, and she's trans/intersex; Dallas spent some time as a smuggler after being dishonorably discharged).

* AlienBlood: Famously introduced the alien creatures as having sickly yellowish acid blood. They attempted to cut off one of the facehugger legs to rescue Kane but the instant their scalpel touches it a jet of acid starts burning through the deck, and they comment that it's one hell of a defense mechanism, making it highly inadvisable to kill the thing on a sealed spaceship. Later movies establish the xenomorphs as logically having the same trait, but the creature in this movie is never harmed in such a way to confirm it.

* ActionSurvivor: Ripley, who is only a terrified woman struggling to survive.

** The film has a few nods to ''Film/TwoThousandAndOneASpaceOdyssey''. When the ''Nostromo'' starts its descent to LV-426, Music/JerryGoldsmith's score becomes more grandiose which harkens back to the use of classical music during space vehicle scenes (not to mention Dallas listening to a Mozart piece while relaxing on the ''Narcissus''), Kane's suit while dirtied is yellow (Dallas' is red while Lambert's blue) which is the same color of the spacesuit wore by Frank Poole before being killed, Ash [[spoiler:turns out to be a robot following a secret order, although HAL 9000 kills due to a malfunction whereas the Company has given Ash an EvilPlan that consists in treating the crew as expendable to preserve the alien]] and the ''Nostromo''[='=]s self-destruction creates a complex lightshow that resembles the Stargate sequence at certain points.

* PhallicWeapon: [[WordOfGod The filmmakers state]] that the rolled-up adult magazine that [[spoiler:Science Officer Ash]] tries to suffocate Ripley with is meant to be a penis substitute, because [[spoiler:as an android, [[BarbieDollAnatomy he doesn't have one himself]].]]

** Most of the deaths are merely implied rather than shown, with special attention made to [[spoiler:Dallas' death]]. Nothing is seen of what happened [[spoiler:after the Alien springs on him once it's illuminated by the flamethrower's light]], and even the aftermath is unclear, only a burst static and screeching before everything goes silent despite the crew's efforts to raise the victim. As Parker states, when they went inside there was no body, no blood, [[spoiler:just the flamethrower]]. Even worse is [[spoiler:Lambert's death.]] Nothing is seen of what happened, and even the aftermath is not seen clearly, we only hear it happening over the radio. It's probably the scariest death in the film. Given that the last thing we see of [[spoiler:Lambert is the tip of the alien's tail moving up her leg towards her nether regions,]] this is probably just as well. This seemed to be partially due to a cut subplot where the alien wasn't outright killing everyone, but fusing their bodies into some cocoon. Ripley came across this strange nest late in the movie.

* MortonsFork: Near the end of the movie, after failing to abort the SelfDestructMechanism by scant seconds, Ripley is left with the realization she has only five minutes to do one of two things: die certainly aboard the ''USCSS Nostromo'' in a fiery explosion, or take her chances with a horrific death by the alien on the way to the escape shuttle. She takes a moment to let out her frustrations on a nearby monitor, but ultimately chooses the option with at least a sliver of chance for survival.

** In the final scene while in the shuttle with Ripley the alien seems content to lay still and do nothing while Ripley is moving around in the shuttle. ''This is in no way consistent with the behavior of any known real-world predator.'' A tiger or a snake is ''not'' going to ignore the presence of a large creature in its den, but will immediately attack. The alien doesn't do this. It may have realized that Ripley has nowhere to run, and doesn't regard her as a threat. It only reacts when she wanders too close, moving just enough to warn her off. She backs off, and the alien is perfectly content to remain where it is, leaving her alone until it gets hungry... or ''bored.'' Even when Ripley gets out of the locker wearing the spacesuit and sits at the controls, the alien ''still'' can't be bothered to investigate and she has to activate the steam vents to piss it off enough to come out into the open so she can blow it out the airlock. An alternate explanation, which was alluded to in earlier scripts, is that the adult alien has a short lifespan and that it was basically dying of old age by the time it reached the shuttle. It just wants to be left alone until Ripley provokes it enough to get it to attack her. Still another possibility is that the drones go into hibernation at a certain stage (perhaps on the way to becoming [[Film/{{Aliens}} in warriors]]), and it was already nearly asleep, thus why Ripley has to provoke it to make it move.

* {{Hypocrite}}: Ash. He's quite quick to remind the crew [[EncyclopaedicKnowledge of the clause in their contract requiring all transmissions of alien-origin to be investigated]], failure results in total forfeiture of shares. Yet as a ''Science Officer'', he conveniently violates Science Division's basic quarantine laws to suit his own agenda. He's borderline StrawHypocrite also. He disturbingly [[AdmiringTheAbomination admires]] the Alien's hostility, unclouded by conscience, remorse, or delusions of morality. [[spoiler:As a self-aware android he ''hates'' the fact [[ThreeLawsCompliant he's mostly held in check by programmed safeguards]] and adores how the alien is free to kill indiscriminately.]] However, given that he was actually ordered to deliver the alien by any means necessary, this is probably a subversion.

* ClosedCircle: Barring the exploration of the alien ship on the planet and discovering the space jockey, the film takes place entirely on the Nostromo. It's a fairly large mining ship, but it's also made clear they are ten months away from Earth, meaning help is not coming. The movie doesn't spell it out, but the novelization makes it clear that the ship is designed with the idea that the crew will spend the bulk of the journey in hypersleep, meaning the have to deal with the alien quickly to avoid using consumables they'll need at the end of their journey, adding a, while not pressing, still present, time factor.

* UncannyValley: While subtle, there are aspects of Ash's behavior early on that in retrospect suggest he's a robot - his cold demeanor and mechanical, flat speech, as well as some of his movements and posture (e.g. when putting on the space suit). Of course, by the time he attacks Ripley, his facial features, oozing fluids, and superhuman strength make it pretty obvious he's something other than human well before Parker breaks off his head.

* LastWords: [[spoiler:Ash the Android]] specifically asks for some final words before [[spoiler: he is unplugged. He uses them to taunt the remaining heroes]].

** The film has a few nods to ''Film/TwoThousandAndOneASpaceOdyssey''. When the ''Nostromo'' starts its descent to LV-426, Music/JerryGoldsmith's score becomes more grandiose which harkens back to the use of classical music during space vehicle scenes (not to mention Dallas listening to a Mozart piece while relaxing on the ''Narcissus''), Kane's suit while dirtied is yellow (Dallas' is red while Lambert's blue) which is the same color of the spacesuit wore by Frank Poole before being killed, Ash [[spoiler: turns out to be a robot following a secret order, although HAL 9000 kills due to a malfunction whereas the Company has given Ash an EvilPlan that consists in treating the crew as expendable to preserve the alien]] and the ''Nostromo''[='=]s self-destruction creates a complex lightshow that resembles the Stargate sequence at certain points.

* WhamShot: When [[spoiler: Parker knocks Ash upside the head and Ash's head falls off, but hangs on his side thanks to his wires.]]

** The trailer has glimpses of Ash spazzing out. Before TheReveal that he's an android malfunctioning, it looks as though he's in agony of having a chestburster coming out of him.

* MinimalistCast: Only 8 crew members (7 humans and 1 pet cat), and to a lesser extent the Space Jockey, the Alien and a computer voice appear in the movie.
* TheMole: [[spoiler:Science Officer Ash]], who was brought in by the Company to make sure their hidden agenda was carried out.
* MoodWhiplash: The crew are sitting around, enjoying one final meal before going back to hyper sleep, joking with each other, when Kane starts gasping in pain....

* NameOfCain: Played with. Second Officer Kane is a good guy, but he's the first to die and the person that the alien births from.

* NeverGiveTheCaptainAStraightAnswer: Ash does this to Captain Dallas '''twice'''.

* AlienBlood: Famously introduced the alien creatures as having sickly yellowish acid blood. They attempted to cut off one of the facehugger legs to rescue Kane but the instant their scalpel touches it a jet of acid starts burning through the deck, and they comment on how that it's one hell of a defense mechanism. Later movies establish the xenomorphs as logically having the same trait, but the creature in this movie is never harmed in such a way to confirm it.

* CaptainObvious: When it's pointed out to the navigator that they haven't woken up in Earth's solar system, Lambert responds testily, "I ''know'' that!"

* ClosedCircle: Barring the exploration of the alien ship on the planet and discovering the space jockey, the film takes place entirely on the Nostromo. It's a fairly large mining ship, but it's almost made clear they are ten months away from Earth, meaning help is not coming.

* BittersweetEnding: [[spoiler:Not only a rarity for 70's horror movies, but a double whammy in that only Ripley survives and she is the one that no one in the audience expected to survive. Ripley kills the Alien by blowing it out the airlock of the escape shuttle- but is deeply affected by the loss of her friends and crew.]]

* CanonDiscontinuity: Of the Director's Cut sort. Since the Director's Cut was never used, James Cameron was able to do his own reproductive cycle for the Aliens (Queen-Egg-Facehugger-Drone/Queen) instead of the original (Egg-Facehugger-Drone-Victim Becomes Egg).

* ChekhovsGun: [[DefiedTrope Defied.]] The film was made ''cinema verite'' style. Very little is explained for the benefit of the audience, and it ignores typical screenwriting structure in favor of that documentary feel. Events that happen, like the damage the USCSS Nostromo sustains on landing, don't contribute much to the overall narrative besides the verisimilitude of life as a space trucker, and things that ''are'' important such as the existence of Androids, the ship's self-destruct system, etc. aren't mentioned at all until they're necessary for the plot. The characters just take these things for granted and don't spell them out for the audience's sake.

* CranialProcessingUnit: After Ash the Android gets his head knocked off, the other crew members of the ''USCSS Nostromo'' plug his head into the proper equipment and are able to speak with him.

* DramaticSpaceDrifting: Kane's body, hurtling away from the ''USCSS Nostromo''. Also, at the end, the alien himself.

** In the final scene while in the shuttle with Ripley the alien seems content to lay still and do nothing while Ripley is moving around in the shuttle. ''This is in no way consistent with the behavior of any known real-world predator.'' A tiger or a snake is ''not'' going to ignore the presence of a large creature in its den, but will immediately attack. The alien doesn't do this. It may have realized that Ripley has nowhere to run, and doesn't regard her as a threat. It only reacts when she wanders too close, moving just enough to warn her off. She backs off, and the alien is perfectly content to remain where it is, leaving her alone until it gets hungry...or ''bored.'' Even when Ripley gets out of the locker wearing the spacesuit and sits at the controls, the alien ''still'' can't be bothered to investigate and she has to activate the steam vents to piss it off enough to come out into the open so she can blow it out the airlock. An alternate explanation, which was alluded to in earlier scripts, is that the adult alien has a short lifespan and that it was basically dying of old age by the time it reached the shuttle. It just wants to be left alone until Ripley provokes it enough to get it to attack her. Still another possibility is that the drones go into hibernation at a certain stage (perhaps on the way to becoming [[Film/{{Aliens}} in warriors]]), and it was already nearly asleep, thus why Ripley has to provoke it to make it move.

* OneWordTitle: The original script had the working title of ''Star Beast'', which no one was happy with. Dan O'Bannon kept mulling over alternatives, each more pretentious than the last, before rereading the script and seeing how often the characters talk about "the alien," and that word jumped out at him. '''Alien'''. Both a noun and an adjective, describing something that cannot be described, because it is ''alien''. And thus, one of the most famous one-word titles was born, telling you exactly what the film was about. . . by telling you nothing at all.

* PuzzleBoss: "Big Chap" aka "Kane's Son" is easily a famous non-video-game and also even [[JustifiedTrope justified]] example of this trope as the horrifically ineffective nature of the few manmade weapons seen throughout the film necessitates the heavy usage of the general environment against him with it all ultimately culminating in Ellen Ripley [[ThrownOutTheAirlock throwing him out of the airlock seen aboard the ''Narcissus'']] during the film's PostClimaxConfrontation as already mentioned above.

* SailorEarth: The Nostromo's usual science officer, whom Ash replaced by order of the company.

* SlasherSmile: Evoked when the Alien bares its teeth [[spoiler:at Parker before opening its jaws to kill him with the inner mouth.]]

* CoversAlwaysLie: Applies to movie posters too: The large, cracking egg prominently displayed on the film poster and in the original trailer is not at all what the Alien really hatches from.

* AdmiringTheAbomination: Science officer Ash acts like this toward the Xenomorph Drone.

** After the chestburster scene, the movie rachets up the tension as the crew detects movement that might be the Xenomorph... only for the cat to jump out to scare the characters and the audience, and Brett dies while trying to catch the cat to stop any more false scares.

* ContinuousDecompression: As part of the FinalBattle, when the Xenomorph Drone is ThrownOutTheAirlock by Ripley.

** Played straight when Captain Dallas goes into the air ducts to try to drive the Xenomorph Drone into an airlock and blow it into space as he carries a radio with him to talk to the rest of the crew, and they use a tracking device to let him know the Xenomorph Drone is getting closer and closer to him until it attacks and kills him off.

* DieHardOnAnX: Inverted. The Xenomorph Drone nicknamed "Big Chap" or alternatively "Kane's Son" is [=McClane=].

** During Lambert's death, the Xenomorph Drone sinewy tail can be seen sliding up in between her legs, and all that's known from her death for now are the strange grunts (of pain) heard by Ripley over her radio.

* DramaticSpaceDrifting: Kane's body, hurtling away from the ''USCSS Nostromo''. Also, at the end, the Xenomorph Drone himself.

* DwindlingParty: The lone Xenomorph Drone takes out one under-armed crew member after another.

* EvilPlan: [[spoiler:Ash seeks to bring a Xenomorph to his bosses on Earth, regardless of who gets hurt.]]

* MortonsFork: Near the end of the movie, after failing to abort the SelfDestructMechanism by scant seconds, Ripley is left with the realization she has only five minutes to do one of two things: die certainly aboard the ''USCSS Nostromo'' in a fiery explosion, or take her chances with a horrific death by the Xenomorph on the way to the escape shuttle. She takes a moment to let out her frustrations on a nearby monitor, but ultimately chooses the option with at least a sliver of chance for survival.
* NameOfCain: Played with. Second Officer Kane is a good guy, but he's the first to die and the person that the Xenomorph births from.

* PostClimaxConfrontation: At first, Ripley seemingly escapes further harm aboard the Narcissus life-boat just as the USCSS Nostromo self-destructs, only for the Xenomorph Drone to both suddenly and unexpectedly confront her one final time and also for her to have to throw him right out of the nearby airlock in order to be able to both save herself and also resolve the film's central conflict once and for all by doing so.

* MortonsFork: Near the end of the movie, [[spoiler:after failing to abort the SelfDestructMechanism by scant seconds, Ripley is left with the realization she has only five minutes to do one of two things: die certainly in the ''Nostromo'' in a fiery explosion, or take her chances with a horrific death by the Alien on the way to the escape shuttle. She takes a moment to let out her frustrations on a nearby monitor, but ultimately chooses the option with at least a sliver of chance for survival.]]
* NameOfCain: Played with. Second Officer Kane is a good guy, but [[spoiler:he's the first to die and the person which the Alien births from.]]

* NeverRecycleYourSchemes: A heroic DoubleSubversion. After [[spoiler:Dallas is killed in the air shaft]], Ripley decides to try [[spoiler:Dallas's]] plan a second time. Lambert thinks Ripley is insane, but then Ripley reveals she's modifying the plan. It's actually ''a good plan,'' and it likely would have worked, except [[spoiler:Ash turned out to be TheMole]]. After that reveal, Ripley abandons the plan; they don't have enough people to make it work, now that they're down to three the "abandon ship in the shuttle" plan is viable, and she's finally beginning to freak out from what's been going on.

* PostPeakOil: In the novelization, the ''Nostromo'' is hauling an oil refinery instead of an ore refinery, because Earth "burned every last drop." No oil means no plastics, and Earth "could do without energy sooner than it could do without plastics." Echoed by Arthur C Clarke, who was fond of saying that, to paraphrase, petrochemicals are too precious to burn.

* RasterVision: Seen on the ''Nostromo''[='=]s various computer monitors.
* RecycledInSpace:
** ''Alien'' was originally billed as "''Film/{{Jaws}}'' [-IN SPACE!-]" to producers. WordOfGod says that it's ''Film/TheThingFromAnotherWorld'' [-ON A SPACESHIP-], right down to the motion detector (a Geiger counter in the original film).

* RewatchBonus: A ''lot'' of Ash's actions make much more sense in hindsight with TheReveal. For example, his attempt at brushing off Ripley's concerns about the translated DistressCall and dissuading her from going out to warn the away-crew is because he can't risk them not making contact and infection with the Alien. He also shows plenty of reluctance to do anything that might harm the Alien, whether directly or indirectly. He's also looking at images of the developing alien inside Kane before the big dinner scene.

* ScreamingWoman:
** Ripley is an aversion. The only times she screams is being startled when she discovers the Alien approaching her as she's preparing to hit the airlock near the end. Or muffled screams when Ash tries to suffocate her with a rolled up magazine.
** Lambert is the traditional version, most notably in her final scene when she's paralyzed with fear as the alien advances on her.

* OnlySaneMan: In spite of the anger it earned her from the rest of the crew for trying to enforce it, Ripley was absolutely right about the 24 hour quarantine. [[spoiler:If everyone had listened to her, it's very possible she wouldn't have been the only survivor.]]

** In the final scene while in the shuttle with Ripley the alien seems content to lay still and do nothing while Ripley is moving around in the shuttle. ''This is in no way consistent with the behavior of any known real-world predator.'' A tiger or a snake is ''not'' going to ignore the presence of a large creature in its den, but will immediately attack. The alien doesn't do this. It may have realized that Ripley has nowhere to run, and doesn't regard her as a threat. It only reacts when she wanders too close, moving just enough to warn her off. She backs off, and the alien is perfectly content to remain where it is, leaving her alone until it gets hungry...or ''bored.'' Even when Ripley gets out of the locker wearing the spacesuit and sits at the controls, the alien ''still'' can't be bothered to investigate and she has to activate the steam vents to piss it off enough to come out into the open so she can blow it out the airlock. An alternate explanation, which was alluded to in earlier scripts, is that the adult alien has a short lifespan and that it was basically dying of old age by the time it reached the shuttle. It just wants to be left alone until Ripley provokes it enough to get it to attack her. Still another possibility is that the drones go into hibernation at a certain stage (perhaps on the way to becoming [[Film/{{Aliens}} a warrior]]), and it was already nearly asleep, thus why Ripley has to provoke it to make it move.

** In the final scene while in the shuttle with Ripley the alien seems content to lay still and do nothing while Ripley is moving around in the shuttle. ''This is in no way consistent with the behavior of any known real-world predator.'' A tiger or a bear is ''not'' going to ignore the presence of a large creature in its den, but will immediately attack. The alien doesn't do this. It may have realized that Ripley has nowhere to run, and doesn't regard her as a threat. It only reacts when she wanders too close, moving just enough to warn her off. She backs off, and the alien is perfectly content to remain where it is, leaving her alone until it gets hungry...or ''bored.'' Even when Ripley gets out of the locker wearing the spacesuit and sits at the controls, the alien ''still'' can't be bothered to investigate and she has to activate the steam vents to piss it off enough to come out into the open so she can blow it out the airlock. An alternate explanation, which was alluded to in earlier scripts, is that the adult alien has a short lifespan and that it was basically dying of old age by the time it reached the shuttle. It just wants to be left alone until Ripley provokes it enough to get it to attack her. Still another possibility is that the creatures go into hibernation at a certain stage (perhaps on the way to becoming [[Film/{{Aliens}} a queen]]), and it was already nearly asleep, thus why Ripley has to provoke it to make it move.

* AdaptedOut: The novelization by Creator/AlanDeanFoster notably leaves out the Space Jockey from the crashed ship. What they find instead is the distress beacon itself, and [[spoiler: Ash later gives Ripley, Lambert and Parker the background on the full meaning of the message and the motivations of those who left it.]]
* AdmiringTheAbomination: Science officer Ash acts like this toward the alien.

* AIIsACrapshoot: [[spoiler:Science Officer Ash]] is programmed to put [[spoiler:his]] mission above the lives of the crew. [[spoiler:He ends up going berserk when Ripley [[RoboticReveal discovers the truth]]. It's played with in the sense that he's not really going rogue, and is perfectly following his given orders. They just come from the Company, not the rest of the crew.]]

'''[[spoiler:Ash the Android]]:''' I repeat, all other priorities are rescinded.

* AllWebbedUp: In a deleted scene restored in the director's cut, Ripley found [[spoiler:Dallas and Brett]] completely cocooned, and slowly transforming into more Alien eggs.
* AnyoneCanDie: The characters died in more or less reverse order of how famous the actors playing them were (in 1979) - [[spoiler:Tom Skerritt, John Hurt, and even Veronica Cartwright were all familiar to audiences, while Creator/SigourneyWeaver was the only entirely unknown actor in the cast, with just four minor credits]]. The deaths of the characters felt like a downward spiral, and Ripley's demise seemed inevitable. The tension of the last ten minutes (with the ship's computer voice counting them off) was almost unbearable. Ripley's survival was, for the era in which the film was made, shocking (a ''lot'' of 70s-era horror movies had {{downer ending}}s, and some critics even argued that horror movies ''had to'' have downer endings to be proper horror movies), and until the end credits rolled, the audience still expected the alien to pop up somewhere. This was actually Ridley Scott's originally intended ending -the alien was going to bite Ripley's head off in the shuttle and make the last log entry in her voice- but ExecutiveMeddling insisted that the monster had to die, so Ripley was spared.

* ArbitrarySkepticism: Ripley wants to get rid of the FaceHugger carcass, because they already know that the alien creature [[AlienBlood bleeds acid]] and have no clue what will happen after it's dead. Ash counters this by snarking at Ripley that it probably isn't a zombie. [[spoiler:The truth is that he's just following his programmed orders to preserve the creature, and presumably the Facehugger's remains, and the crew's been marked expendable so he doesn't care what the corpse might do to them]].

* ArtisticLicenseBiology: It is simply not possible for the creature to grow as rapidly as it did without consuming a massive amount of food, which is not shown at all. ''Film/AlienCovenant'' handwaves it by confirming a popular fan theory that [[spoiler: the entire Xenomorph race are engineered bioweapons, and thus probably do not need to eat]], but this still doesn't explain where the biomass comes from.
* AsYouKnow: Averted as far back as the scripting process. Dan O'Bannon agonized over how to include details such as what the ship was for and why it was where it was into the dialogue, with cringers like "Hey, aren't you glad we decided to buy our own ship and go mineral prospecting on asteroids now?" that are basically convoluted derivatives of "as you know." Finally, O'Bannon decided that anything that didn't fit naturally into the character's mouths was information the audience didn't need to know. Ridley Scott continued the trend into the film, with just a short text describing what the ''Nostromo'' is, where it's going, and (kind of) why, everything else is only discussed as it becomes relevant to the plot, like the existence of [[spoiler:androids]].

** After the chestburster scene, the movie rachets up the tension as the crew detects movement that might be the alien... only for the cat to jump out to scare the characters and the audience. [[spoiler:Brett dies while trying to catch the cat to stop any more false scares.]]

* ChekhovsGun: [[DefiedTrope Defied.]] The film was made ''cinema verite'' style. Very little is explained for the benefit of the audience, and it ignores typical screenwriting structure in favor of that documentary feel. Events that happen, like the damage the Nostromo sustains on landing, don't contribute much to the overall narrative besides the verisimilitude of life as a space trucker, and things that ''are'' important such as the existence of androids, the ship's self-destruct system, etc. aren't mentioned at all until they're necessary for the plot. The characters just take these things for granted and don't spell them out for the audience's sake.

* ClothingDamage: Parker's shirt is ripped apart during the struggle with [[spoiler: Science Officer Ash]].
* ContinuousDecompression: As part of the FinalBattle, when the Alien is ThrownOutTheAirlock by Ripley.

* CranialProcessingUnit: After [[spoiler:Ash the Android]] gets his head knocked off, the other crew members of the ''Nostromo'' plug his head into the proper equipment and are able to speak with him.
* CuriosityKilledTheCast: Kane's overzealous impulse to investigate the eggs leads to [[spoiler:himself and then almost the entire crew being killed]]. Also Ash, for his insistence on keeping the face-hugger for scientific study, [[spoiler:until it's revealed that he knew exactly what it was and was prioritizing bringing it to Earth over saving the crew]].

* DeadStarWalking: Tom Skerritt received top billing over Creator/SigourneyWeaver. [[spoiler:Ripley was never meant to be the main protagonist, merely the FinalGirl.]]

** Played straight when [[spoiler:Captain Dallas]] goes into the air ducts to try to drive the Alien into an airlock and blow it into space. He carries a radio with him to talk to the rest of the crew. They use a tracking device to let him know the alien is getting closer and closer, until it attacks and kills him.
--->[[spoiler:Move, Dallas. Get out! No! Not that way! The other way! Dallas? Dallas!]]
** Also [[spoiler:Lambert and Parker]] are killed by the monster off-screen while being in radio contact with Ripley.

* DeerInTheHeadlights: Lambert suffers from this when facing the Alien. It leads directly to [[spoiler: Parker's death and consequently hers, as he can't use the flamethrower on it without killing her.]]
* DieHardOnAnX: Inverted. The alien is [=McClane=].

* TheDissenterIsAlwaysRight: Ripley at first seems harsh and wrong for refusing to let the crew in when a face-hugger attacked one of them, coldly citing quarantine procedures. In the end, it turns out she was entirely correct, and had they listened to her [[spoiler: she might not have been the only survivor]].

** During Lambert's death, the Alien's sinewy tail can be seen sliding up between her legs. All that's known from her death are the strange grunts (of pain) heard by Ripley over her radio.

* DramaticSpaceDrifting: [[spoiler:Kane's]] body, hurtling away from the ''Nostromo''. Also, at the end, [[spoiler:the alien itself.]]

* DwindlingParty: The Alien takes out one crew member after another.
* DyingSmirk: [[spoiler:Ash goes out with the infamous line, [[EvilGloating "I can't lie to you about your chances, but... you have my sympathies,"]] and signs off with a smug smile.]]

** The trailer has glimpses of [[spoiler: Ash spazzing out]]. Before TheReveal that [[spoiler:he's an android malfunctioning]], it looks as though he's in agony of having a chestburster coming out of him.

* NotQuiteDead: Ash, [[spoiler:after his head is torn off]], gets his second wind and goes after Parker.

* TheReveal: Several, but the two most significant ones are when [[spoiler:Ripley finds out that the Company had planned the mission from the very start and considers the crew [[WeHaveReserves expendable]], and when Ash is revealed to be a robot working for them.]]
-->'''[[spoiler:Ash the Android]]:''' There is an explanation for this, you know.
* RewatchBonus: A ''lot'' of [[spoiler:Ash's]] actions make much more sense in hindsight with TheReveal. For example, his attempt at brushing off Ripley's concerns about the translated DistressCall and dissuading her from going out to warn the away-crew [[spoiler:is because he can't risk them not making contact and infection with the Alien.]] He also shows plenty of reluctance to do anything [[spoiler:that might harm the Alien]], whether directly or indirectly. He's also looking at images of the developing alien inside Kane before the big dinner scene.
* RidiculouslyHumanRobot: No one knew that [[spoiler:Ash was an android.]]
* RoboticReveal: [[spoiler:Ash is revealed to be an android when he starts sweating/bleeding white fluid, and it is confirmed when his head is knocked off his shoulders.]]

** Ripley is an aversion. The only times she screams is being startled when she discovers the Alien approaching her as she's preparing to hit the airlock near the end. Or muffled screams when Ash tries to [[spoiler:suffocate her with a rolled up magazine.]]
** Lambert is the traditional version, most notably [[spoiler:in her final scene when she's paralyzed with fear as the alien advances on her]].
* ScrewThisImOutOfHere: Lambert proposes they just abandon ship after [[spoiler:Dallas']] death, but Ripley has to remind her the shuttle can't support [[spoiler:four]]. [[spoiler:When Ripley, Parker and Lambert learn the truth about Ash's mission and about how they're all expendable to The Company if it means they get the Alien, they decide to activate the ''Nostromo''[='=]s SelfDestructMechanism and blow it to kingdom come with the Alien while taking their chances in the escape shuttle with the three of them.]]

%%* CatchPhrase: Brett's "Right."; {{Discussed|Trope}} by Ripley and Parker in one scene.