Undertale / Tropes C to F

You can view the main article here.

Tropes A here.

Tropes B here.

Tropes C-F here

Tropes G-N here.

Tropes O-Z here.

Note: "No Mercy" and "Genocide" are two names for the same, officially unnamed, route of the game.

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Trope C

• Call a Hit Point a "Smeerp": Even if it sounds like a lie at first, the game does use the term "LOVE" for LV instead of Level. Well, it does stand for Level Of ViolencE.
• Call-Back:
  • In the Neutral run, when you first encounter Asgore, he greets you with a bit of small talk. In the No Mercy run, Sans repeats the conversation almost verbatim.
    Neutral Final Boss: Nice day today, huh? Birds are singing, flowers are blooming... Perfect weather for a game of catch.
    Genocide Final Boss: it's a beautiful day outside. birds are singing, flowers are blooming... on days like these, kids like you...
    Should be burning in hell.
  • While walking with the Monster Kid in Waterfall, they tell you about how cool it would be if Undyne could visit their school and beat up all the teachers. They then take it back, saying Undyne would be too cool to beat up someone innocent. Later in Hotland, if you call Undyne in the room where kids are skipping school, Undyne comments on how she could make school a cooler place by visiting and beating up the teachers. She then takes it back, saying she wouldn't beat up a teacher.
  • If you run from the fight with Toriel in the Ruins and go to sleep, you'll hear a voice saying "Wake up, [player name]. You are the future of humans and monsters," essentially telling you that you have to go through with the Toriel fight. Towards the end of a true Pacifist run, in the True Lab, you can hear Asgore say the same thing in the VHS recordings, with a much darker meaning. That wasn't a guiding voice the first time you heard it. It was a memory.
  • Several bosses in the game (including Doggo and Papyrus) "block the way", but it's intentionally done with the first major boss in the game and the last boss of a True Pacifist run.
  • Going through the opening sequence multiple times will elicit different responses from Flowey. Eventually, he'll just say "Don't you have anything better to do?" After you exhaust all of Asriel's lines in the Playable Epilogue, he'll say the exact same thing, complete with a knowing smile (as he used to be Flowey, and may well have said the line earlier).
  • If you talk to Toriel before "fighting" the training dummy, she will suggest you start with a joke, and gives an example: "What does a skeleton tile his roof with? SHIN-gles!" In the true pacifist ending, she tells this same joke, much to Sans's delight and Papyrus's dismay.
  • Invoked during the "I Know You're in There Somewhere" Fight during the True Final Boss fight on a Pacifist run. By making the Lost Souls remember the good times they had with you (and their subsequent character development), you manage to restore their memories and save them.
  • Subverted in the Final Boss fight in the No Mercy route. Sans will mention that he senses something good inside you in what seems to be a refernce to Neutral and Pacifist playthroughs where the player potentially resolved things peacefully, but if you jump on it and do spare him, he will insta-kill you, all while mocking your naivety that you even believed for a second that he could spare his brother's murderer, though he also hopes he did get through to you, and asks you not to come back.
• Cash Gate: Downplayed as it's not strictly necessary to win, but buying a Spider Donut or Spider Cider from Muffet's bake sale in Hotland will allow you to completely skip her boss fight in a Neutral or Pacifist run. Since they cost 9999G each, though, good luck actually collecting that much cash. ^note It's possible to buy spider products from the bake sale in the Ruins for a much cheaper price to make Muffet instantly spareable, though this doesn't skip her fight and requires you to use them in battle first.
• Cardboard Prison: Papyrus's attempt to use his and Sans's shed as an impromptu prison for the player is quite unimpressive, to say the least. His only measure for hindering escape attempts is placing a fence across the room, which has such large gaps between the bars that it can be circumvented by walking out between them, and the door to the shed turns out to be locked from the inside.
• Cassandra Truth: When you first meet Sans and Papyrus, Sans tells you to hide behind "a conveniently shaped lamp" while he covers for you. The next scene involves Sans invoking this trope for laughs by telling Papyrus the lamp might help him find a human, much to Papyrus's frustration.
• Cat Girl: Catty and Mad Mew Mew both qualify as this, especially the latter.
• Central Theme:
  • Exploring the relationship between the player, their avatar, and the NPCs in the game world.
  • Asking what a person would do if there were no consequences for their actions, when they could simply reset the entire world back to the beginning on a whim. What would that mean for the people in the world itself? What does that say about a video game player who completes the worst possible ending just because they have to see what happens?
  • The power of stories, and how they reflect us so that we can analyze ourselves and become better people.
  • The Power of Love, and how it can be both a force for good and a force for bad.
• Cerebus Retcon:
  • Using save points has the most innocuous things somehow fill the protagonist with determination. These kind of lines are later used in a more serious context for the various Final Bosses, and it's eventually revealed that determination is an actual plot element of the game, and it's shown how it's not always a good thing, in the form of horrifically mutated creatures who were injected with it.
  • Sans's laziness is also given a similar treatment. He's aware that you have been resetting the timeline. Knowing that everything he does will amount to nothing since you can undo it whenever you want, he finally just stopped caring. He only breaks his nonintervention to stop the player from completing a No Mercy file, the only outcome that can never be fully taken back.
  • Alphys' complete lack of any social skills and low self-esteem is played very comically when you're heading through Hotland, to the point where she posts a "picture of herself" that's really a frilly trash can like it's a point of pride. Then you find out in the Pacifist ending that her low self-esteem stems from failure after failure at trying to break the barrier, the consequences of which were the creation of Flowey and several monsters falling victim to Body Horror (whose families are missing them and ask her regularly for some kind of closure). She's also very realistically depressed and has contemplated suicide (and in almost all endings where Mettaton or Undyne die, goes through with it).
• Cessation of Existence: For all the pointless death you can inflict on all the characters, there's still the tiniest grain of reassurance that, given the game's heavy focus on things like SOULs, they have some kind of afterlife to go to once it's all over. Except Flowey, who is sentient but has no SOUL to speak of. Near the end of a Genocide run, he tells you that he tried to commit suicide not long after waking for the first time, thinking that life without the ability to feel compassion or love wasn't a life worth living, but managed to stop himself via a Reset when he was suddenly overwhelmed by a terrifying realization: "If you don't have a SOUL, what happens when you...?" This is made even worse when you kill Flowey just two fights later in the same run. There's hope that, since his actual SOUL passed on a long time ago, he'll be able to join it once he dies, but otherwise the outcome looks pretty bleak.
• Challenge Run: Fulfilling certain requirements throughout the game will give you unique text at the end of a Neutral Run when Sans calls you. Completing the hardest one (Never using healing items, keeping the bandage on the whole game, and remaining at LV 1) has him outright comment that you like to challenge yourself before asking you not to brag about it.
• A Chat with Satan: The Fallen Child. They are Frisk’s Shadow Archetype and seem to think they know your dark side quite well. They do give a test of character of sorts with the ERASE or DO NOT choice, as well as the choice to sell your soul. If that wasn’t enough to convince you, they even call themself “the demon that comes when people call [their] name” if you complete two Genocide Routes. Of course, by the time you see them, you've failed the test of character big-time.
• Chekhov's Gun:
  • An optional one. When exploring the ruins at the beginning, the player can find some spiders' bake sale and can buy some food from them. This food comes in handy when confronted by Muffet later on; using the food during the battle shows that you are a friend of spiders and ends the fight.
  • During their lunch date, Sans will tell the player that Papyrus claims a flower occasionally appears to him and tells him secrets and predictions. While Sans assumes that someone is playing a trick on Papyrus using an Echo Flower, the "flower" is, of course, Flowey. And who tells Papyrus to gather everyone in one place at the end of the Pacifist route so he can absorb all their SOULs...?
  • Similarly to the bake sale, if you keep the pie from the beginning of the game all the way to the Asgore boss fight, eating it will lower his stats, and during the confrontation with Asgore and Toriel as lost souls, eating the pie will help you SAVE them.
  • Another optional one: if you sing with Shyren until she departs of her own accord instead of you sparing her, when you encounter Knight Knight in the CORE, you can sing Shyren's song instead of a generic melody, making her fall asleep in two turns instead of four.
  • If you read the books in the library early in the game, they say that it would take the SOULs of almost every monster to equal the power of a single human SOUL. In the True Pacifist ending, Asriel is able to use the power of every monster SOUL to break the barrier with six human SOULs instead of seven.
    • The only exceptions seem to be Napstablook and the person who likes hearing people knocking on the door, because neither of them answered their door when the flash of light happened.
• Chekhov's Gunman:
  • The training dummy in the Ruins appears innocuous enough, if slightly odd in that it will float away if the player stalls in battle long enough. It turns out to be the cousin of another dummy in Waterfall, who gives various reasons for fighting you depending on what you did with the dummy at the beginning of the game.
  • Flowey appears twice in the ruins and then disappears from the rest of the game aside from a few Easter Eggs. At the end of the game, he kills Asgore and steals the human SOULs, completing his master plan and revealing himself to be the true Big Bad of the game.
• Chest Monster: The True-Pacifist-exclusive dungeon has an enemy encounter disguised as a Save Point. One hint that the not-save-point is a trap is that it's blocking a path.
• Citywide Evacuation: On a Genocide Route, the Monster Towns of the Underground learn that the Player Character is murdering everything in their path and evacuate before their arrival. Undyne pulls a You Shall Not Pass! against the PC and dies happy that she bought time for the monsters to get to safety.
• Close-Knit Community: The Underground is this — everyone knows each other (with the exception of monsters residing in the Ruins, since the entrance sealed off from the rest of the Underground; only Napstablook can travel between them freely), and everyone cares deeply for each other. If you kill even one NPC, no matter how minor, people will notice and care. It's probably inevitable it turned out this way; most of the monsters' population was wiped out in the war, and the few who remain are all stuck in the same relatively small area for the foreseeable future. If that won't force you to get to know your neighbors…
• Color-Coded for Your Convenience:
  • Some bosses can change the color of your Soul, which changes the way its movement works. Red is the default, and can move freely. Blue subjects your soul to gravity, dragging it to the ground and forcing you to jump to move vertically. Green prevents you from moving, but gives you a shield that you can point in different directions to block incoming attacks. Purple forces you to hop between horizontal lines for vertical movement, but still allows you to move back and forth along those lines. Yellow allows your soul to shoot projectiles. All of these changes disable the Flee option.
  • Enemy projectiles have colors as well. White projectiles are normal and do damage when touched. Light blue attacks won't hurt you as long as you aren't moving, while orange ones will only hurt you if you're staying still. Green attacks will heal you when you touch them and/or must be touched to Spare an enemy. Grey attacks (only so far used by ghosts/objects possessed by ghosts) do nothing at all. They're used to relay messages in a non-harmful manner. Red attacks, similar to grey attacks, are often used as a warning in order to allow you to know when an attack is coming.
• Color Motif: Playing the Ball game reveals tidbits of the significant traits colors represent:
  • Red's trait is unknown, but it's assumed that it may be Determination. This is the color of the protagonist's SOUL.
  • Orange represents Bravery; accordingly, when faced with Orange attacks, you have to unflinchingly move straight through them in order to avoid taking damage. It's implied that the Human with the Orange SOUL wore the Tough Glove and the Manly Bandana.
  • Yellow represents Justice; tellingly, it's one of the colors that Sans' eye flashes during your fight with him at the end of the Genocide route. It's implied that the Human with the Yellow SOUL wore the Cowboy Hat and Empty Gun.
  • Green represents Kindness; if you see green-colored "bullets" in battle, then they will heal you instead of hurt you and they often advance the battle, pacifying your opponents and allowing you to spare them. It is also the color Undyne turns your SOUL during your fight with her; while this prevents you from running away, it also gives you a shield with which you can block her attacks. The Human with the Green SOUL is implied to have donned the Stained Apron and the Burnt Pan, the former which lets you regenerate 1 HP every other turn, and the other which increases the HP recovery of healing items by +4.
  • Teal represents Patience; you have to stand still in order to avoid taking damage from these attacks. It is also the second color that Sans' eye flashes during your fight with him, and say what you want about Sans, but he has been nothing if not patient with you up until now.
  • Blue represents Integrity; it weighs your SOUL down with gravity, turning the gameplay into a platformer instead of a Shoot 'Em Up. The Human with the Blue SOUL is implied to have worn the Old Tutu and the Ballet Shoes.
  • Purple represents Perseverance; when your SOUL is turned purple, you're trapped on three lines that you have to jump between in order to avoid the enemy's attacks. The human with the purple SOUL is implied to have used the Cloudy Glasses and Torn Notebook.
• Comic Role Play: En route to the Golden Ending, the player will find themself on a date with Alphys. She admits that she likes Undyne, but can't work up the nerve to tell her. The player suggests that they roleplay as practice, and then chooses between serious or goofy role-playing lines. Of course, it spirals out of control regardless of the player's choices.
• Company Cross References: The 2021 Xbox One port's exclusive poker-themed border includes cameos of Jevil and C. Round from Deltarune.
• Completion Mockery: As noted in Achievement Mockery, the trophies show disdain over the trophy system. Get all the trophies, and you will get the platinum trophy, which is named "Don't You Have Anything Better To Do?"
• The Computer Is a Cheating Bastard:
  • An in-universe example. Flowey closes the game before you can stop him from using the human SOULs. When you boot the game up again, he has already changed the world to eliminate all other threats and replaced your file with his, which is at LV 9999 despite the highest reachable LV being 20. He then literally shatters that file, before you can overwrite or delete it. At the beginning of the fight, he makes a quicksave. Throughout the fight, he makes quicksaves right before attacking so he can unexpectedly load them later, but loading them doesn't give you back any of your health. When you finally beat him, he loads his first save, thus undoing all of your progress. (Or so he thinks…)
  • Another in-universe example: Asgore gets the first turn and uses it to destroy the MERCY button.
  • Even worse, Sans gets the first turn, attacks you on the menus by exploiting the fact that your SOUL is the cursor, completely ignores mercy invulnerability, and dodges your attacks. He's so good at reading people's faces that he can tell if you've died to him before, and he exploits this knowledge by interrupting his own dialogue at varying points to attack you.
• Context-Sensitive Button: The ACT option in battles. When it is selected for an enemy, a set of options unique for them pops up, and you can choose any one of them. The effects they have include doing nothing, changing your stats or the enemy's stats, affecting their next attack, allowing them to be spared or making them leave the battle, and any number of miscellaneous effects depending on the enemy.
• Continuing is Painful: Averted for the most part, except during Papyrus' fight. Unlike most battles, where you die and are sent back to the last place you saved, it's completely impossible to die during Papyrus' fight, as he captures you and the battle ends once you hit 1 HP. While this might seem like a good thing, this means that after every fight, the healing items you used in the previous fight are still gone, and in subsequent tries, you'll have to waste money to buy more healing items.
• Contrived Coincidence:
  • The conveniently-shaped lamp that Sans tells you to hide behind is shaped exactly like the protagonist seen from the side and hides them perfectly.
  • The color tile puzzle that Papyrus generates for you appears to be this, since the "random" configuration that appears is two straight rows of passable tiles surrounded by red tiles. "Appears" being the operative word, because it's very likely that Mettaton (who was used to create the puzzle) had control over the outcome and decided to mess with everyone by making it so simple.
• Controllable Helplessness:
  • You can turn in place while webbed up by Muffet, and move around freely while Endogeny approaches, but you can't escape in either case.
  • During part of the pacifist True Final Boss, you are unable to select any menu option except Act->Struggle, which just says "Can't move your body." Attacks during this phase are almost impossible to dodge, but it also doesn't matter how many times you get hit.
  • At the end of Flowey's boss battle, he traps your SOUL in a circle of bullets so he can gloat a bit before trying to kill you. You can still move your SOUL around, but touching any of the bullets just teleports it back to the center. Do it enough, and Flowey will actually get annoyed and yell at you to cut it out.
• Convection, Schmonvection: Zigzagged. While Undyne's armor heats up significantly while crossing a bridge over lava, to the point where she passes out, you are perfectly fine in that same area and suffer no heat-related issues, even when you make it hotter to appease a monster. Then again, Undyne is a fish monster wearing heavy steel armor. Your character is wearing a simple striped shirt. Also, the Royal Guardsmen apparently have "cooling dirt" on their armor, which you need to polish away in order to get one of them to succumb to the heat and take his armor off as well. Since Undyne is normally stationed in Waterfall, her armor would have no need for such enhancement.
• "Could Have Avoided This!" Plot: Two in the True Pacifist Ending:
  • When Toriel confronts Asgore, she tells him that he could've stopped his quest at one human SOUL, crossed the barrier himself, and taken six more human SOULs. Since she mentioned it could've ended their imprisonment peacefully, it stands to reason that she meant SOULs from recently-deceased humans, since it's established that human SOULs persist after death.
  • If you choose to stay with Toriel, she invokes this, saying the player could've said that at the very beginning, and that would've been the end of it. But she adds she's glad they didn't, since now they are free.
• Crapsack World: Played for Laughs if you play in Hard Mode. You access Hardcore Mode by naming the Fallen Child "Frisk". In this mode, Toriel makes you snail pie, you face the hardest monsters first, and after you defeat Toriel, the Annoying Dog tells you it ends here.
  Narration after taking a third piece of Monster Candy: In this hellish world, you can only take 3 pieces of candy...
• Crazy-Prepared: Alphys makes several upgrades to your cell phone that come in handy later. Some of these upgrades — the jetpack, the bomb defusal program, Yellow Soul mode — come in handy for parts of what turns out to be a Worked Shoot, so this trope was invoked. Things become much more difficult for Alphys when Mettaton goes Off the Rails in the CORE, forcing her to adjust/improvise several times in order to keep the player safe.
• Creative Closing Credits: The special thanks portion has you dodging the names of the 918 Kickstarter backers who pledged high enough for that reward. Dodge all of them, and you'll be able to access the Annoying Dog's room in Snowdin.
• Creepy Jazz Music:
  • Downplayed with "Ghost Fight". The music itself fits this trope, being a swingy, but somewhat haunting tune. But what prevents it from being a straight example is the context in which it plays. It's the boss music for Napstablook, a Shrinking Violet ghost who is reluctant to fight — certainly not the type of character usually associated with this type of music.
  • And then played straight with "Dummy!", the Boss Remix that plays while fighting Mad Dummy.
• Crime of Self-Defense:
  • A lot of the monsters the player encounters will attack and usually try to kill them. The player may think attacking them back and killing them is self-defense, but the game treats it as murder. However, a book in the library says that magic is how monsters express themselves, which implies that damage done to the human, with the exception of the bosses and mercenaries late in the game, is incidental.
  • If you make certain choices, Sans will say he understands that you might have been defending yourself, but then he asks you if a person with a special power has a responsibility to use it to help people. If you say yes, his eyes go dark and he asks why you killed his brother, then disappears.
• Cringe Comedy: The date with Alphys on the Pacifist route. Between Alphys's complete lack of social skills, and the fact that she's obviously pining for Undyne, it's awkward from the word "go". But then you start to roleplay an interaction between Alphys and Undyne, and things get even worse. (Or better, since that's when the scene goes from amusing to hilarious.) And then Undyne overhears you.
• Crippling Overspecialization: The monster race as a whole in terms of power. Their main distinction from humanity is their association with magic, which allows them to, among other things, absorb a human SOUL once the carrier has perished. If even one SOUL is absorbed, a monster becomes exceedingly powerful — the game's backstory implies that they could level an entire village with ease — and if they absorb seven, they become a being on the level of godhood. Without a SOUL to absorb, however, monsters are so outmatched by humanity that it only takes a single, particularly determined child to wipe them all out if the player so chooses it.
• Critical Existence Failure:
  • Monsters don't show damage, but disintegrate into dust after their health is depleted. The only ones who don't drop dead after being defeated are Undyne (who was probably running on borrowed time, anyway) and King Asgore. This might catch a player off guard if they weren't intending to kill the first boss.
  • This is actually averted for most enemies. Unlike in most RPGs, where characters take more or less the same damage regardless of health, enemies in this game take more damage as their HP gets lower. This can screw over players who try to spare monsters by beating them to critical health.
  • This is played straight for the player, whose SOUL takes the same damage from an attack no matter how much HP they have left. It's also something exploited by the more Technical Pacifist characters who don't want to kill you, such as Toriel and Papyrus; they're willing to reduce your HP to a low level, but once you're that weakened, they'll either deliberately avoid landing their attacks (Toriel) or just detain you (Papyrus). Since you don't seem to suffer any physical injuries from attacks to your SOUL, it seems to be fine with them. Asgore, who also doesn't want to kill you but feels that he has to, exploits this in a much more somber fashion by always giving you a Last Chance Hit Point.
  • Played with during the final battle of the Pacifist run. As you're reaching out to save Asriel's soul, he lashes out with a final attack that deals an incredible amount of unavoidable damage. The player's health drops: first to one, then to .90, then to .50, all the way down to a billionth of a single hit point. As the game says at the beginning, though: you only lose when you reach 0 HP. Through determination alone, Frisk prevents that from happening. An alternate explanation of this involves Asriel not wanting to kill you, and thus being unable to do lethal damage.
• Critical Hit:
  • While it isn't a game mechanic per se, there is something like it present: In a No Mercy run, attacking almost any major character will cause you to deal an extremely high amount of damage in a single attack, almost instantly causing death. This is caused by them being caught unprepared and by your LOVE and Determination being especially potent on the most prominent characters.
  • This catches a lot of players by surprise even in a Pacifist run: when fighting Toriel, many players try to weaken her to the point where she can be shown Mercy. Once she's down below 1/3rd of her health, though, the next hit will eliminate her. Toby Fox clearly feeds off the tears of his audience.
• Crosshair Aware:
  • The final soul in the Photoshop Flowey battle spouts three crosshairs at once before letting off a salvo of bullets. This also helps you see where the healing items will be.
  • Asriel's Shocker Breaker is basically a carpet bombing using rainbow lightning, and there are exclamation marks right where they will land.
• Cruel and Unusual Death:
  • At the end of the No Mercy route, you get to butcher Flowey repeatedly into smaller and smaller pieces until he's totally gone. Considering most fights end with a clean kill, be it from massive damage or a sneak attack, this is easily the most brutal way to die in the entire game.
  • In the backstory, the first human dies of buttercup poisoning, an incredibly painful way to die. Symptoms include bloody diarrhea, excessive salivation, colic, and blistering of the intestines. This is presumably to free the monsters or to exact revenge on the humans for unknown reasons.
  • Most monsters turn to dust when they die. Not Undyne. She has a greater amount of Determination than most monsters, meaning that in a desperate situation, she can will herself to stay alive for just a bit longer. The downside to this is that monsters' bodies don't respond well to Determination, so when the player kills her, her will to live causes her to start melting. She's fully conscious during this and even tries to take you down with her, though at this point, her magic is so weak she can't really do anything to you.
• Cruel Twist Ending: If you follow a No Mercy run with a Pacifist run. Everything seems to be normal… up until the last moment, in which it's revealed that the player character has been possessed by the Fallen Child and is then implied to destroy everyone and everything within the game, apart from themself and the player character.
• Cue the Sun: The pacifist ending has the human leading their new friends outside of Mt. Ebott into a sunrise, and they comment on how beautiful it is. This is due to the fight with Asriel taking all night, given the encounter with Asgore happens during sunset.
• Curb-Stomp Battle:
  • As you can learn throughout the game, the war that the humans won against the monsters was one of these. In fact, not a single human was killed during the war. This makes sense when you consider that Frisk, who is a mere child, can completely eradicate the monster population single-handedly, and it's likely that adult warriors and soldiers probably fought in the war itself. Combine that with the knowledge that a human's killing intent and prior killing history makes them even deadlier to monsters, and it's no shock that seasoned, experienced soldiers were able to almost effortlessly wipe out most of the world's monsters.
  • In a No Mercy run, almost every single fight will end with you obliterating the monster with a single strike. The game is intentionally balanced to be challenging to a Frisk at LV 1, at their absolute weakest. There are, however, two notable exceptions who will turn this trope on you: Undyne the Undying, and Sans.
• Cutting the Knot: The second "X's to O's" puzzle is more difficult than the others and can be frustrating to figure out. However, a nearby tree has a hidden switch that immediately solves the puzzle when you press it.

Trope D

• Damn You, Muscle Memory!: In the last leg of the battle against Asriel, the "SAVE" button is always flashing, which can trick you into thinking it's selected when it's not — after every SOUL you save, the cursor defaults back to "Fight", making it easy to accidentally attack. Not helping is the fact that, just before you're able to save your friends, "ACT", which "SAVE" takes the place of, is all you can select, and "SAVE" is selected by default the first time the option unlocks. As a result, you might not even realize "FIGHT" can be selected until it's too late.
• Dark Horse Victory: If you kill only all the "Boss" characters like Toriel, Papyrus, etc., but spare every other encounter, then the Annoying Dog somehow manages to become president of the Underground, and Sans comments that "Somehow, everyone seems happier this way".
• Dark Is Not Evil:
  • Although even the monsters refer to themselves as "monsters", none that are actually encountered within the game are truly evil, Fantastic Racism aside. In fact, most Random Encounters just want you to do something with them before they're willing to leave you alone. Even the few monsters identified as "bullies" will allow you to spare them simply by being nice.
  • In general, this can count for locations as well. Be it Sans's room or the abandoned lab, they are creepy and have pitch black areas, but there is nothing really dangerous there.
• Dark Reprise:
  • In the demo, if you kill Toriel, then return to her house, her theme plays in a hauntingly lowered pitch and tempo, reflecting her death.
  • Once you're on-track for the No Mercy ending, the same thing happens to every area theme in the game.
  • After depleting an area of its monsters, "Your Best Friend" plays, slowed down to the point it's oppressive, booming, and nearly unrecognizable.
  • A distorted, solemn version of the Snowdin theme plays while "fighting" one of the monsters Alyphys injected with Determination, who is really the mother of an enemy from that area.
  • The True Lab theme itself sets Alphys' theme to dark harmonies, to accompany her backstory.
  • Zigzagged with Flowey's theme, "Your Best Friend", which turns into "Your Best Nightmare", a manic, distorted, utterly insane version when Flowey becomes Photoshop Flowey. However, it's eventually replaced with "Finale", a more hopeful version, once the player is finally able to start getting the upper hand on Photoshop Flowey.
  • Due to very different tempo and instrumentation, it's not obvious, but "Battle Against a True Hero" (heard when fighting Undyne in the No Mercy route) uses a melody which is very similar to "Spear of Justice" (Undyne's usual battle theme in Neutral and Pacifist Runs). The similarity is due to the fact that "Spear of Justice" showcases Undyne as a Hot-Blooded, bombastic warrior who is filled with undue enthusiasm about attacking you, while "Battle Against a True Hero" shows the same character in a more solemn, serious state as a heroine trying to hold out hope in the face of unspeakable evil that seriously threatens to plunge everything into death and despair.
  • The song that plays during her last stand before dying is also a sad rendition of part of Undyne's theme (really a common tune throughout the game, but it appears during the preceding fight). The full version of that song plays during the neutral ending as well.
• Dating Sim:
  • Papyrus's sidequest includes a style parody of them. Your dialog choices don't matter as he interprets everything you say in the best possible light, and your "dating power" is something that is actively measured during the segment, with the bar measuring it eventually bursting apart.
  • You are led to believe that you'll have one with Alphys on a Pacifist run as a callback, but it's quickly subverted as she cuts the "Dating Start!" music short and admits that you're not really the person she has feelings for.
• The Dead Have Names: If you spare Toriel but kill other monsters in the Ruins, Flowey calls you out by naming the monsters that may have been your victims, saying that each one could have been "someone else's Toriel."
• Deadly Euphemism: Throughout your journey, you'll hear about monsters who have "fallen down". It's revealed through Alphys' entries in the True Lab, and in Snowdin library, that "fallen down" means "comatose and near death".
• Deal with the Devil: If you want to play the game again after completing a genocide run, you need to make one of these with the Fallen Child, giving them your SOUL in exchange for recreating the world you destroyed. The consequences of this deal don't become apparent until you try completing the True Pacifist run and discover that the Golden Ending is no longer golden.
• Death of a Child:
  • You can kill the teenage Snowdrake (and the game makes sure to call you out on it when you meet his father).
  • The Plot-Triggering Deaths are a tragic example: Asriel Dreemurr and the first Fallen Human were both little kids when they died.
• Deconstruction: The single greatest example of this is how the game treats the act of fighting monsters. In this game the enemies you fight are people instead of just goons to mow down without a second thought. Killing them is treated like an act of murder by the characters and playing the game like a typical RPG leads to the absolute worst ending and demonstrates just how much of a sociopath a typical RPG protagonist would be in real life. On the flip side this also means that violence isn’t the only option. If the enemies are people, that means that they can be reasoned with and convinced to back down peacefully.
  • Killing a monster results in it turning into dust and vanishing, with No Body Left Behind. In this game, that is no mere abstraction: unless they saw you do it, no one can prove that you killed someone or that said someone is even dead. They can only suspect and infer, with all the implications thereof. For instance, the only warning sign that you are on a Genocide run is that monsters soon become hard to find after you arrive, which only the most alert or suspicious might put together in time to warn others.
• Decon-Recon Switch:
  • For the Determinator trope: Determination is an actual physical force that allows things to come back to life. Injecting it into most monsters turns them into the Body Horror Amalgamates, but the Determination wielded by the player and Flowey gives them the ability to SAVE. Flowey and the Genocide run player have abused their ability to save to kill everyone, and Flowey in particular makes use of the ability to SAVE in his boss fight to kill you over and over again. And it isn't much better in a Neutral or Pacifist run, since Flowey is manipulating the player's Determination to get the Golden Ending in order to get the power that he wants. However, in the Pacifist Ending, it's ultimately the player's Determination to save everyone, including Asriel, that allows them to hang on until the end and Earn Your Happy Ending.
  • Most of the game is a long, hard examination of traditional JRPG tropes and cliches, but things can easily be switched from a deconstruction to a reconstruction by simply playing through the Pacifist route. Unless you sold your SOUL beforehand.
• Deconstructor Fleet: Though not immediately apparent, the game is a Deconstruction of RPGs, both on a superficial level from sarcastic flavor text and characters (staying in the Snowed Inn, for example, has the innkeeper give your money back, mentioning you were only up there for two minutes) as well as the deeper plot. It also examines 100% Completion on a meta level. What if there were alternate ways of getting from Point A to Point B, and the person going through the motions happens to have the ability to go back and explore these routes after going through one? What if they remember going through the motions? What if someone else can remember what they did in a previous loop? If the world inside the game is real, what happens to it when the player reloads a save, or starts New Game Plus? It also takes a look at a number of gaming tropes, like the Determinator, Save Scumming, Turn-Based Combat, Level Grinding, and, most of all, Video Game Cruelty Potential. And, for the truly curious, Dummied Out.
• Defeat Means Friendship: Defeating your enemies non-violently allows you to befriend them. Subverted if you go the violent route — that just causes you to cut a bloody^note well, dusty swath through them.
• Deliberately Monochrome:
  • Monsters are always monochrome in battle, but are colored on the overworld. This is because all monster SOULs are grey. The one exception is Froggit, which is the same color in both the overworld and in battle. The monochrome battle sprites are averted in a few cases, such as Toriel’s eyes and Sans’...blood?
  • The game's intro sequence is in sepia. This is to mask the fact that the human you see in the intro sequence is not the main character, but rather, the first human to have ever fallen into the Underground, revealed by a Wham Shot in the Golden Ending.
  • New Home is a colorless shade of white and grey, the only color in sight being the golden flowers scattered around the house area. This is presumably meant to represent how lifeless Asgore's world has been since the death of his children.
• Dem Bones: Sans and Papyrus are an interesting case: They look like human skeletons, yet they are actually a species of monster. There is no mention of them dying in the past, implying that they have always been skeletons. Supported by Papyrus thinking that humans "descended" from skeletons, showing that their skeletons are different.
• Determinator: All of humanity, according to the Pacifist ending: the wish to continue living and the drive to make it happen are a combination that (most) monsters don't have and which all monsters physically cannot take. This is one of the reasons humans are so much stronger than monsters.
• Detrimental Determination: Determination as a neutral quality is deconstructed; There is indeed the good kind of determination, to not harm others in your attempts to leave the underground. However, if the player experiments and decides to play the game like a normal RPG or even decides to purposely become a juggernaut, determinedly killing all various characters they encounter, the game not only subtly chastises them for it (taking the fun out of the game, puzzles already solved, preventing the player from solving them), but also deconstructs the moral implications of it, making the monsters not only run in fear, but also changing the whole tone of the game, eventually culminating in at least two Nintendo Hard boss fights, attempting to get you to change your stance and reset, and also permanently altering your save file and ending if you do decide to go through with your total massacre.
• Developer's Foresight: Has its own page.
• Developer's Room:
  • One is hidden a few screens before Snowdin. You can unlock it by successfully avoiding the special thanks credits during the true pacifist ending. Sadly, you cannot fight the dog inside…
  • Two appear as placeholder screens in case something goes wrong within the game. They involve the Annoying Dog either standing within the center of the screen or sleeping while one of two otherwise unused songs (depending on the screen) plays in the background. The only way to get out is to reset the game.
• Diagonal Speed Boost: The game doesn't reduce your horizontal or vertical velocity if you move diagonally. While this can be beneficial on the map, it can feel awkward in battle, particularly for players of Shoot Em Ups that are used to this trope being averted. Fortunately, it can be disabled in the options menu.
• Die Laughing:
  • If you dispatch Toriel in a particularly cruel way, she'll declare that you're worse than the monsters outside the Ruins while laughing hysterically at her own foolishness for having wanted to protect you from them.
  • Some foes in Hotland (Muffet, Madjick, Astigmatism) make a giggling sound when you land a hit on them, which results in this trope if you One-Hit Kill them during a No Mercy route.
• Diminishing Returns for Balance: Using a Punch Card while a Tough Glove is equipped provides +6 to attack. It can be done repeatedly in one fight, but doing so for the third time only grants a +3 bonus, which drops to +2 for each subsequent use.
• Disc-One Nuke: You can get the Temmie Armor before you are even halfway through the game, though this requires an enormous amount of money. Not only does it have the highest defense value of any armor in the game^note except for The Locket, it also increases your attack, the invincibility frames after getting hit, and restores one point of health every turn in combat. Temmie even says that it makes the game too easy.
• Does This Remind You of Anything?: The first thing to emerge from the reveal of Mettaton EX is something crotch-level and long. It's probably the most explicit thing, in a fight loaded with innuendo.
• A Dog Named "Dog":
  • According to Word of God, the name of the child who you hang out with in Waterfall is actually “Kid.”
  • In Snowdin, there is Snowdrake and Chilldrake. They’re made of snow and ice, which makes them a snow drake and a chill drake.
  • The Temmies. It seems to be the name of the species and every member of it (except for Bob).
• Don't Make Me Destroy You: The final boss of the No Mercy route takes this attitude with the player character once they first meet. The boss says "you are really not gonna like what happens next" if you fight them, trying to warn the human not to advance. When the human steps forward anyway, the boss gives a glorified shrug and starts the battle.
• Double Unlock: The Temmie Armor requires you to pay one thousand gold to get the option to buy it, then a very high amount of gold to actually obtain it.
• Do Well, But Not Perfect: In Thundersnail, if you win, you earn 9 G, which is less than the entry fee of 10 G! Napstablook explains that they have to make a profit somehow. If you lose by a very narrow margin, Napstablook will instead give you 30 G to avoid disappointing the snail you were cheering on.
• Down in the Dumps: Partway through Waterfall, you fall into the Trash Zone, which, fittingly, is filled with garbage. And a mini-boss. You return there for Alphys’ date.
• Downer Ending: Generally speaking, the more monsters you kill, the more of a downer the ending is. The worst ending, naturally, follows the genocide run and actually gets even worse if you follow the genocide run up by selling your SOUL and doing another pacifist run.
• Do Wrong, Right: Toriel points out to Asgore before the Boss Fight with Asriel that instead of waiting for other monsters to kill seven humans and take their SOULs, he could have only killed one, crossed the barrier by combining the soul with his own, and gotten six more from the surface. He can't deny that she has a point.
• Dramatic Wind:
  • When Papyrus poses and speaks about how great he is, a breeze ruffles his cape.
  • The save point at Undyne's battle arena, plus a random line when fighting her, "The wind is howling."
  • Asgore's cape noticeably billows as he fights you.
  • When the cast all meet to convince you and Asgore not to fight, Undyne's sprite has her hair blowing, while nobody else is affected.
  • When the Fallen Child sends you to a black screen to wait for ten minutes, a sound like wind blowing can be heard in the background.
• Dreamworks Face:
  • One of the sprites in the game files shows Toriel making this face and is named spr_face_torieldreamworks_0.
  • Papyrus has a confident expression during the battle with him.
• Driven to Suicide: The topic of suicide is touched upon in the game, but never directly stated.
  • Implied to be the fate of Dr. Alphys in certain Neutral endings. Broadly speaking, this usually occurs if you kill Undyne or Mettaton. It does not occur in the Golden Ending, but on the way there, you'll have a conversation with that character, after learning just why they might have "done something... cowardly" even if you did everything right.
  • Also a part of Flowey's backstory. After awakening as a flower in Asgore's garden, he eventually found that he couldn't feel any love or warmth from his parents. Not wanting to live in a world without love, he committed suicide. The only reason he is still alive is because, during his attempt, he realized he was afraid of actually dying, and that unwillingness to die caused him to wake back up in the garden as though nothing had ever happened. This is how he discovered his ability to save and load.
  • If you fight Asgore again (before befriending Alphys) and spare him again, he will kill himself in order for you to take his soul.
  • Asriel also wonders if this might be the reason the protagonist climbed Mt. Ebott at the start of the game.
    Frisk... Why did you come here? Everyone knows the legend, right...? "Travellers who climb Mt. Ebott are said to disappear." ... Frisk. Why would you ever climb a mountain like that? Was it foolishness? Was it fate? Or was it... Because you...?
  • It is implied by two conversations with Flowey and Asriel that the Fallen Human tried to kill themself by climbing Mt. Ebott, due to their hatred of humanity.
    Asriel: I know why Chara climbed the mountain. It wasn't for a very happy reason.
    Flowey: But I decided it wasn't worth living anymore. I decided to follow your footsteps. I would erase myself from existence.
• Driving Question: An interesting variant, as it is one not posed to the characters, but rather the audience: "Don't you have anything better to do?", referring to the need to 100% games some people feel when completing video games, and asking said player if they are willing to commit heinous acts to see everything the game has to offer.
• Dude, Not Funny!: Invoked and seemingly parodied. In one battle, you have the option to tell Woshua, a Neat Freak monster, one "dirty" joke about "two kids who played in a muddy flower garden," another about "a kid who slept in the soil," and a final one about "a kid who ate a pie with their bare hands". Woshua doesn't react well to these jokes and reduces his attack. Then on a Pacifist run, you later learn about the king's children Asriel and the Fallen Child accidentally feeding their father a pie with buttercups instead of cups of butter, that they picked the flowers, and of the Fallen killing themself with buttercups and wanting to be "buried in their village" when they wanted to kill all the humans once across the barrier. Think about it and you realize that you are joking about the last hope of monsters being killed, which makes Woshua's reaction more heartbreaking.
• Due to the Dead: With monsters, this trope is a bit difficult to do since the monsters, when they die, turn into dust, and for this reason Alphys accidentally infused a flower with Asriel's remains, trapping him in that state. For humans, however, their bodies notably don't dissolve, so Asgore and Toriel show a lot of respect for the corpses even as Asgore takes their souls in preparation to break the barrier. Toriel also took the Fallen Child's body and is implied to have buried it in a field of golden flowers, the field on which Frisk lands.

Trope E

• Early-Installment Weirdness:
  • The demo has some oddities in the combat system that aren't carried over to the final game. Namely, it allows the player to earn EXP by lowering monsters' health before sparing them, while EXP can only be earned by killing them in the final game. Since EXP stands for Execution Points, it wouldn't make sense to be able to earn any without killing anything. Vegetoids in the demo also must be spared by attacking them first, and the "Devour" ACT will kill them outright; in the final game, they can be spared through ACTs like every other monster and "Devour" never harms the Vegetoid.
  • The Kickstarter videos have some different characterizations from the actual game. Sans is seen closing his mouth to drink lemonade, while he never closes his mouth in the game, sporting a goofy grin at all times. Toriel is also shown manifesting lemonade in thin air, though the only magic she's shown to have in the game is fire magic.
• Earn Your Bad Ending:
  • Getting a Game Over in the Boss Battle against Toriel takes some effort. You really have to be trying, since her attacks will cancel early if you have less than half health at the start of an attack. If you are one hit away from death, her attacks will actively avoid you. With 11 or 12 HP, you need to run into three fireballs before her attack ends.
  • A No Mercy run requires you to do much more work than any other run, killing every random encounter in each area (all of them; you won't discover there's a finite amount unless you're a habitual grinder, and the amount never actually depletes unless you kill them). Other than that, it is way easier than a neutral or pacifist run because most bosses get one-shotted by your evil and hatred, and several puzzles are solved for you, but has some tremendous increases in difficulty in Undyne the Undying and Sans. All this for the worst ending in the game.
  • If you want, you can do the No Mercy run again after you do it once, with the same results; the Fallen Child even questions you for it. Doing a Pacifist run after you sell your SOUL to the Fallen Child isn't any better.
• Earn Your Happy Ending: If you spared every enemy and reached the final room with no kills? Not only did you not increase your LV (meaning you beat the game on the starting 20 HP), you still don't get the good ending unless you've befriended everybody. Then after that, you go through the True Lab, and find out the secrets of the hidden lab, as well as the truth of Flowey's existence, followed by another boss battle. The other monsters also get their happy endings:
  • Toriel opens up a school and works as a teacher there. She also adopts Frisk and dotes on them if you choose to stay with her.
  • Asgore is relieved the monsters are free. He maintains the hedges at Toriel's school, slowly mending their relationship.
  • Alphys is rightly fired from her position as Royal Scientist, since she caused all the problems with Flowey and the Amalgamates. She's actually happy about that, because it means the burden is no longer on her. Undyne and she start a relationship, complete with smooches.
  • Papyrus doesn't become a Royal Guard member, but he gets the freedom to explore his purpose on the surface, and gets a snazzy sportscar to boost. You can tell he prefers that.
  • Sans is relieved that everyone is alive and can see the sunrise. It means he can troll Papyrus and text puns to Toriel.
  • Mettaton becomes a star, reconciles with Napstablook, and hires Shyren to sing for him as well as Napstablook as a DJ. Burgerpants also finally gets his chance to shine… as a tree.
  • Frisk, no matter what you choose, earns their freedom and gains a lot of friends.
• Easter Egg:
  • The door in the Snowdin Woods will open if you dodge all of the Kickstarter backer credits perfectly in the Golden Ending.
  • If you do nothing but hum when facing Shyren, this will start a mini-plot where you and she improve your singing careers. In-game, this means you can make Knight Knight fall asleep faster by singing. This also activates Shyren's yellow title in the epilogue.
  • Each character in the ending credits / epilogue has two descriptions. The first is a standard white description, and the second is a yellow description if you did something unique with them. One of the most obscure is Aaron's, which is triggered by wandering around the lake near Napstablook's house while playing one of their CDs.
  • When you reach the Last Corridor on a Pacifist run, save the game before you talk to Sans. As soon as you stop talking to each other, reload the game and talk to him again. Keep doing this until you get the key to his room. Search his room for a silver key to the door behind his house. There's a secret lab with blueprints and a covered-up machine there.
  • There's a hidden encounter in Hotland. Follow the path from the Right Floor 2 elevator until you reach the long, straight area with a T-intersection. There's an invisible path going north. Go there when your computer's time and date are set for October 10th at 8 PM^note The Nintendo Switch version of the game removes the time prerequisite, only requiring that the date be correct to encounter So Sorry.
  • Unpacking the game allows access to a secret audio file from Toby politely asking them to not spoil secrets and post them on the internet. Take a listen.
  • There's an Abandoned Quiche under a bench east of the second Bridge Seed puzzle room. You can use the seeds to get there.
  • Whenever a new game is started, a random number between 1 and 100 is generated. This number, known as the fun value, is used to trigger various random events throughout the game. These events range from phone calls of no consequence to the appearance of NPCs that talk about a character who otherwise goes unmentioned.
  • If you play the game in windowed mode, the title of the game window changes several times:
    • During the opera segment in Hotland, it reads "Undertale: The Musical".
    • When you restart the game after Flowey forcibly closes it and the intro glitches out, the title cycles through random gibberish. It then reads "Floweytale" until the next boss is defeated.
    • If you finish a No Mercy run, the game has no title after the Fallen Child destroys the world.
  • When the Fallen Child attacks the game itself and fills the screen with 9s, the window shifts and shakes repeatedly if the game is in windowed mode.
  • If the game crashes (unintentionally) or if you launch Program Manager while the game is running, the game's internal description is "Leading Brand UNDERTALE-type software".
• Easy Levels, Hard Bosses: To a heavy degree. Standard enemies, while not effortless, can usually be spared either instantly or after a single ACT, with only a few exceptions, and attacking them will bring them down pretty quickly, especially if you've gotten good with weapon timing and have higher LV. Bosses (at least the ones from Papyrus and beyond) are another story; they have high health, they employ Bullet Hell with their attacks, they mix up the dodging system, and Sparing them requires either a thoughtful series of actions or dragging the fight out for quite a while (over 20 or more turns for the major bosses; most enemy battles will take 2-4 turns at the most). This is especially true in the No Mercy path; you can plow through enemies with ease, but anything that can take more than a hit from you is far harder to beat than anything on other routes.
• Easy-Mode Mockery: Inverted. Hard Mode is the joke game.
• The Echoer: Echo Flowers are bioluminescent plants that repeat the last sounds they were exposed to, always speech. The protagonist can hear conversations by other people through the flowers.
• An Economy Is You:
  • The Snowdin Shop only sells gloves, bandannas, popsicles, and cinnamon rolls.
  • Gerson's shop sells crab apples, tea that boosts your speed in battle, and notebooks and glasses that increase your invincibility frames.
• Effortless Achievement: The PlayStation 4 and Play Station Vita versions are mostly just taking the piss when it comes to its trophies, aside from a few fairly standard "reach <this specific area>" trophies. A few of them are literally just joke trophies acquired by picking up your first four items, and the rest is just donating gold to the Dog Shrine, up to 350G, which isn't even remotely difficult, it's just a matter of knowing where the shrine is in the first place. You can get a platinum without even finishing the game. Considering Toby Fox outright worded the announcement of trophy support as an apology, Sony mandates trophy support on both systems, and achievements clash with one of the game's themes, it makes sense that he'd go out of his way to not only poke fun at the system, but also rob trophy hunters of any sense of achievement.
• Egopolis: In the Neutral ending where Mettaton becomes the new ruler of the Underground, he turns it into his "personal paradise", filled with statues of him, his name spelled out in flowers, and so on. Under his rule, the Underground suffers from major problems, such as overcrowding and economic collapse, but he keeps the crowds placated with his brainwashing TV show and covering everything with glitter.
• Empathic Environment: The save point immediately before the battle with Undyne reads "The wind is howling. You're filled with determination…" If you kill her, the wind stops, and its message changes accordingly.
• Endgame+: While you can't reach the true pacifist ending the first time through the game (since you're required to get a neutral ending first), if you do a pacifist run first anyway, it's possible to reach said ending just by reloading the save and backtracking a bit (and doing the date scenes with Papyrus and Undyne if you hadn't already), rather than needing to start from the beginning.
• Enemy Roll Call: The credits names off all the enemies, who designed them, and what happened to them in the end.
• Enemy Scan: The "Check" ACT, available for almost every battle, gives a brief description of the enemy and their attack and defense. While it isn't too helpful, it does give a bit of insight on some of the characters, and reveals some odd details (namely that the hardest boss in the game has the worst stats of any enemy, because he doesn't need anything better). It doesn't work on every battle, however, most noticeably with the Amalgamates, who are too terrifying and alien to be described with a simple check; the game doesn't even provide the option for some of them. For some battles, it even lies to you. ^note Alternatively, your enemy scan is being lied to and then passing the misinformation on to you, if you go with the theory that Chara is the narrator and provides the CHECK information. And in the case of the Toriel and Asgore fights, it's more likely that it's describing what their stats would be if they weren't holding back. Oh, that enemy has 5 attack? NOPE, it has twenty. This can only really be found through the game code, though.
• Entertainment Below Their Age: Despite being old enough to hold a steady job, Papyrus's favorite book is Peekaboo With Fluffy Bunny.
• Epic Fail:
  • You can "lose" the fight against the tutorial dummy, an "enemy" that does absolutely nothing. Should you continuously miss your attacks or spare it repeatedly, it will "get tired of your aimless shenanigans" and just float away.
  • Undyne's attempt at cooking, or more specifically, teaching you how to cook, ends in her house catching fire. It's still on fire during the Playable Epilogue.
  • The Lesser Dog spends the entire game after its encounter playing poker against itself and losing. No, not Solitaire or some other one-player card game. It's playing poker, a game in which victory or defeat is completely a matter of chance (and face-reading, deception, confidence, and misinformation gambits, but that doesn't really apply since it's playing against itself). And it's losing. Somehow. It doesn't manage to "win" its one-dog poker game until the Playable Epilogue.
• Epileptic Flashing Lights: During the final boss of the neutral route, when the SOULs are dispelling Flowey's Photoshop form, his parts flash in different rainbow colors.
• Establishing Series Moment: When you exit the ruins, Flowey will talk to you, his dialogue varying depending on the actions the player takes. Killing anyone will have him taunt you for it, and if you save Toriel but kill any normal enemies, he will also mention that. In the slightly likely chance you kill Toriel and restart to save her, he'll reveal his knowledge of this and your past murder before leaving.
• Eternal Engine: The CORE, a high-tech center that serves as the power source of the Underground. When the player arrives, it’s been taken over by Mettaton, who leaves traps and mercenaries everywhere.
• Everyone Can See It: During Mettaton's quiz, he asks who Alphys' crush is. If the player responds "Undyne", she blushes and Mettaton says "I told you it was obvious. Even the human figured it out." Even more so in her date sequence where she attempts to offer you metal polish, scale cream, and a spear repair kit. One guess for who those are meant for.
• Everybody Lives: The True Pacifist ending naturally ends with everyone in the Underground alive. In fact, everyone being alive is important to the end of the run; Flowey has to absorb all the monsters' SOULs to gain his maximum power, so killing even the least important of monsters locks you out of it (though the direct reason is that you can't get Undyne's Letter if there have been any casualties). However, the epilogue reveals that Napstablook’s soul wasn't taken, indicating that not every single soul was needed.
  • It's possible to come VERY close to this in the best neutral ending. If you spare everyone including the final boss, the only casualty will be Asgore, who will either be killed by Flowey or kill himself if spared.
• Everything Fades: Monsters turn to dust when killed, explaining why they vanish after being fought. This is notably incorporated into monster funerals and comes up a few times in the plot of the game.
• Evil Is Not a Toy: One of the major plot points is that you can go back and change your mind about doing almost anything. However, if you complete a Genocide route, it will permanently ruin the happy ending of any following Pacifist run, implying that the Fallen Child will kill off the other characters later.
• Evil Is Easy:
  • EXP can only be gained by fighting enemies; sparing them only gives you gold. Of course, this means that if you don't fight anyone, your life bar will never get bigger...
  • Taking the full No Mercy route eventually subverts this. The amount of encounters in this route that don't go down in one or two turns can be counted on one hand. But those encounters are the most challenging in any route of the game.
• Evil Only Has to Win Once:
  • In full force on a No Mercy run. The few characters who can stand up to you will most likely kill you over and over again… but you have determination on your side to bring you back from the dead and they don't, so unless you reset, they're ultimately fighting a hopeless battle. Likewise, completing a No Mercy run just once is all the Fallen needs to destroy the world and steal your SOUL, which negatively affects all subsequent True Pacifist playthroughs.
  • Also Inverted in a No Mercy run, as you only have to show Mercy once to lock yourself out of it. ^note Well, technically, you have to not kill a unique monster (read: miniboss, boss, or Snowdrake) to lock yourself out of the No Mercy route; you can spare as many generic monsters (including Snowdrake) as you want and still complete a No Mercy run as long as you meet your kill quota by the end of each area (and kill all the unique monsters (including Snowdrake◊, who you can spare as often as you want as long as you eventually kill him)). You can even spare Lesser Dog by never confronting it in the first place (which is admittedly a complete matter of luck, as you do have to kill it to continue the No Mercy run if you do meet it in a Random Encounter), which overall creates a bizarre inversion of What Measure Is a Mook?. When you discover the consequences of your murderous playthrough, you might reflect on how you made a willing effort to bring them about. You could have made that world less miserable any time you wanted… and it would have been so easy.
• Evolving Music: As you befriend more and more characters, the title screen's music becomes more lively as more and more instruments are added in. Completing the True Pacifist run and seeing the epilogue makes it become slow and eerie, reflecting the emptiness of the Underground after all the monsters have gone free as well as the fact that the game itself doesn't want you to reset and resume playing after finally giving the characters a happy ending.
• Evolving Title Screen: The characters you've befriended throughout the game will appear on the title screen. Completing the True Pacifist run and seeing the epilogue returns it to its original state because everyone you've befriended has left for the surface by that point.
• Exactly What It Says on the Tin:
  • "Song That Might Play When You Fight Sans." It doesn't play when you fight Sans; the operative word is "Might".
  • "Bird That Carries You Over A Disproportionately Small Gap" describes the exact context this song plays within.
  • The "Conveniently Shaped Lamp". It's a lamp, conveniently shaped to "perfectly" hide the protagonist.
  • Several of Asgore's names for places are quite self-explanatory:
    • "Home" is the monsters' (original) home. This name mostly applies for the backstory. By the time Frisk ends up in the Undergound, it's taken on another name: the Ruins.
    • "Waterfall" is a cave full of waterfalls.
    • "Hotland" is a cave full of lava and fire.
    • "New Home" is the new and current home for himself and the monster capital.
• Exact Words:
  • The Tag Line for the game: "The Friendly RPG Where Nobody Has To Die." Sure, nobody has to die… but anyone can.
  • One right when you start the game: "Name the fallen human." They don't tell you which fallen human you're naming… You also get a rather blunt and obvious game rule thrown at you stating that the game ends when HP reaches zero. The True Pacifist ending's final boss fight against Asriel has him throw everything he has to try and kill Frisk out of desperation, but they hold on through Determination to the point where their HP ticks down to the decimals and by the time Asriel stops, you're left with one-billionth of a Hit Point, thus not hitting zero.
  • "Three out of four gray rocks recommend you push them." The fourth rock isn't as much of a pushover — as in, you literally can't push it, because it won't let you. You have to ask it to move.
  • "here goes nothing." Spoken by Sans before doing exactly that: nothing.
  • If you killed Lesser Dog, you can reach the fire exit at Grillby's, but can't actually use it because you're "not made of fire".
  • At one point, Sans warns you that his brother has a Special Attack. The first attack Papyrus puts emphasis on in his fight is his Blue attack, not necessarily his special attack, which will probably further trick people into thinking Papyrus is all bluster before he turns their SOUL blue.
  • Sans and Papyrus have an argument that consists mostly of Papyrus yelling at Sans to clean up, and Sans obeying in the most unhelpful way possible while technically obeying the exact words of Papyrus' commands.
  • "Three gold for the ferry." The rock that carried you will then pay you three gold. "Thanks for stepping on my face."
  • "Song That Might Play When You Fight Sans." Heavy emphasis on "Might": It doesn't actually play when you fight Sans. "MEGALOVANIA" plays instead.
  • The final boss of the Genocide route is described as "the weakest enemy," with only 1 ATK and DEF. Looking in the game's code reveals that not only is your Enemy Scan not deceiving you here, he also only has 1 HP. His stats do accurately describe his capabilities: his attacks only do 1 damage, and a single hit will kill him (like anything else on a No Mercy run). However, just try surviving long enough to actually hit him. And when you do get the chance, he'll casually dodge your attack; the battle turns out to be a sheer endurance match, as you'll quickly find that your only option is to keep trying (and failing) to hit him until he's too exhausted to dodge anymore. Also, while his attacks do indeed do 1 damage, there is No Mercy Invincibility in this battle, and every hit poisons you. Even a slight scrape can shave off a lot of health. (So, again, good luck surviving long enough to wear him down.)
  • When Sans offers to spare you, he says that "[his] job will be a lot easier." And if you accept, he says he "won't let it go to waste." Turns out, he was referring to his job of killing you, and he won't waste an opportunity to do so.
  • One of the last history messages in Waterfall says that, to break the barrier, the power of seven human souls is needed. Combine this with an earlier message that says it would take nearly every monster to equal the power of one human soul and the fact that Asgore already has six souls, and you get Flowey's backup plan to steal all 6 human souls and the souls of almost every monster in the Underground.
  • When Alphys reveals that it takes at least a human SOUL and a monster SOUL to cross the barrier, she laments that in order for you to leave, you'd have to kill Asgore. Toriel is also aware of the minimum amount of power needed, which she points out to Asgore that he could've freed everyone easily years ago if he just used one SOUL to leave and find the rest outside, since Alphys's fact also works in reverse.
  • You have the option of employing this yourself against the Nintendo Switch-exclusive Optional Boss Mad Mew Mew, which gets some Lampshade Hanging if you do. Specifically, Mad Mew Mew asks you to show her what LOVE is. She means literal love, but if you employ the other meaning of LOVE used throughout the game — namely, violence — she remarks, "I suppose I should have expected that" before falling apart.
  • In Snowdin, Doggo informs you that Greater Dog writes "the most beautiful letters" and shows you a message written by Greater Dog. It's just "bark" in a very fancy script, i.e. Greater Dog writes with beautiful letters.
• Experience Penalty: If you reduce Napstablook's HP to 0, they reveal they were lowering their HP on purpose to make you feel better, since they can't die on account of already being a ghost. At the end of the fight, you lose 1 experience point. But the extra-observant may notice that you don't lose any EXP…
• Experience Points: You earn EXP when you kill an enemy. Get enough EXP, and your LV/LOVE increases. Near the end, Sans explains that EXP and LV/LOVE actually stand for "execution points" and "level of violence".
• Explain, Explain... Oh, Crap!:
  • Mettaton asks the player a question about Mew Mew Kissy Cutie during his quiz show. Alphys, who's been shaping the letters of the correct answers with her hands up until that point, excitedly blurts out the answer. She then elaborates about the scene and why she likes it, but realizes she accidentally revealed she was helping the player halfway through a sentence. As she notices, her text starts printing out slower and switches back to standard capitalization from allcaps, and she nervously looks over at Mettaton.
  • Near the end of the Genocide path, Flowey appears and talks about how your determination — the power to cheat death — has surpassed even his, then talks about how similar the two of you are in how you're both willing to kill the other if they got in your way. His expression quickly changes from his usual smug self to one of absolute horror as he puts two and two together…
• Expository Pronoun: The Japanese translation uses pronouns to emphasize the characters' personalities:
  • Flowey uses the non-threatening "boku" and "kimi" because he hides his murderous intentions behind a happy mask. However, he will address you with the harsher "omae" when you piss him off enough.
  • The Hot-Blooded Undyne uses the haughty "kisama" for the player character because of her disdain for humans. However, she refers to herself with the neutral "watashi" instead of the harsh "ore" to reflect her dignity as a member of the royal guard.
  • Sans usually addresses the player character as the familiar "anta" when he's being goofy, but switches to "omae" when he needs to be intimidating. He refers to himself as "oira", which is usually associated with bumpkin types, which Sans isn't. However, it fits his character on a meta level: It also shows how Sans tries to project a loser-ish, slacker image. During the "Lost Souls" fight and segments before he fights you on the worst route, he switches to "ore".
  • Papyrus refers to himself as "ore-sama" (i.e. adding an honorific to the pronoun) because of his massive ego.
• Expressive Health Bar: Hit enemies become shocked/angered/saddened as their sprite shakes, before a number indicating how much damage you dealt rises out of their depleting heath bar.
• Eyepiece Prank: If the player character looks through Sans's telescope in Waterfall, they only see a solid red color. When you exit the telescope, there is a purple ring around their eye.

Trope F

• Fake-Out Opening: It's shown that the opening cutscene isn't the protagonist, Frisk, falling down and entering the underground — rather, it's the Fallen Child who befriended Asriel. Subverted a bit in that it's not the game faking you out, necessarily, but rather your own assumptions about how RPGs work and introduce information, which are then repeatedly tested throughout the game.
• Fake Trap:
  • The corridor of spikes can't harm you because the spikes that aren't part of the correct path only act as barriers. You wouldn't realize this at first because Toriel leads you through.
  • None of Papyrus' traps can actually hurt you. The only trap which seemingly can hurt you is his "invisible electricity maze" if you touch any "walls" while holding the orb. The worst it does when this happens is that you'll get shocked and have to walk away from that area. You'd have had to do this deliberately if Papyrus didn't leave his footprints in the maze to give you said orb in the first place.
• Fantastic Aesop: "If you have the power to rewind time, you have no excuse not to do the very absolute best." The likelihood is this is meant to be taken as an elaborate, fictionalized way of saying Comes Great Responsibility.
• Fantastic Racism: Zig-Zagged. Humans' fear of monsters led to the war, the monsters being trapped underground, and, you know, the whole plot, but Word of God says that after returning to the surface in the Golden Ending, the monsters will be fine, implying that most of humanity has gotten over it. Some monsters — Undyne in particular — aren't too fond of humans, either, but every monster in the Underground is willing to let you go with no further hassle, and even befriend you, if you prove you have no intention of hurting them. On the other hand, there are some monsters that don't realize you are human. On the other other hand, even the ones that do realize it can be befriended if you're nice, Undyne included. And even Undyne has an appreciation for human culture. To put it simply, monster-human relations are complicated.
• Fantasy Kitchen Sink: The setting of Undertale is a place where you can meet a pair of comical skeleton brothers, a genocidal monster flower, a middle-aged pie-baking goat lady, an anime geek dinosaur scientist and a Wrong Genre Savvy Hot-Blooded fish knight.
• The Farmer and the Viper:
  • In the Neutral ending, you have the option to spare Flowey. He not only fails to understand this, but blatantly comments that refusing to put an end to him just means he will continue to torment you and everyone you love. Afterwards, it seems to have somewhat affected him, causing him to reveal the way to get a truly happy ending… only for it to turn out to be a ploy to bring every SOUL into his grasp. And then subverted — after said SOULs remind him of what it's like to feel love (not to mention making him capable of actually feeling it again), he immediately throws out his previous plans of destroying the world in favor of a Stable Time Loop that will allow him to play with you forever, then throws that plan out once he realizes he's being selfish and self-defeating. Even after he releases the SOULs and returns to his original state, he shows remorse for what happened despite his returned lack of love.
  • You in the No Mercy path. Toriel will realize this if you attack her after sparing her.
  • It's also an important part of the backstory. After being taken in by Toriel and Asgore, the "Fallen Child" attempted to manipulate their adoptive brother Asriel into murdering the fallen child's entire village. The end result was that the two of them died, with Asriel being reborn as Flowey. The Fallen Child shows no remorse for this, and on a No Mercy run, they'll gladly see both of their adoptive parents killed. Although this could be subverted, depending on how you interpret the Fallen Child's motivations and their relationship with their adopted family.
  • Within the No Mercy path, it's implied that Flowey's been helping you on your journey by, among other things, solving puzzles for you, just so that you could focus on your goals of destroying everything in your path. You eventually repay his help by killing him. Though it could also be interpreted as the child punishing him for his betrayal, as he will be found trying to warn Asgore about your arrival. When that fails and Asgore gets one-shotted, Flowey finishes Asgore off (which, in this context, comes across as a Mercy Kill), then shatters his SOUL, leaving the child stuck underground.
• A Father to His Men:
  • Undyne is a female example. She makes it very clear how much she cares about Papyrus, though the relationship is more similar to brother and sister than mother and son. If you kill Papyrus, Undyne drops the monologues, and coldly promises to kill you. The only character who cares about Papyrus more is Sans. She also cares very much about the Snowdin Canine Unit and Guards 01 and 02.
  • Asgore also fits. He trained Undyne himself from her childhood and is very caring towards her (and pretty much everyone). There isn't a single monster who dislikes him, except for Toriel.
• Faux Adventure Story: The game looks like a very typical 8-bit RPG with the classical "boy gets lost in the world of monsters" plot… But the thing is, to get the best ending, you have to not kill monsters, so monsters and humans eventually make peace. Otherwise, if you play it like a classical RPG and kill all the monsters for points, you get a bad ending where you become a monster.
• Fighting Back Is Wrong: The game makes a big point out of calling the player out for killing monsters. This disregards the fact that outside of a rare handful, each and every monster you fight attacks you, a child, with intent to kill first, whether out of Fantastic Racism, a sense of duty, or to get good ratings for their television show^note okay, that last one also has the motive of escaping the Underground to entertain people on the surface and preventing Asgore from taking your soul and using it to wipe humanity out. None of your assailants besides Flowey are ever really called to account for attempted child murder.
• Fighting Your Friend: Part of the fight with Asriel on the True Pacifist run involves liberating your friends from his control.
• Final Boss: Photoshop Flowey on Neutral and Sans on No Mercy. Once Photoshop Flowey has been defeated once, Asgore takes his place as final boss of the Neutral route. Asriel, while the True Final Boss of the game as a whole, is technically this for True Pacifist, as well.
• Final-Exam Boss:
  • Many of Asgore's attacks are very similar to Toriel's, in addition to heavily using variations of blue/orange attacks introduced by Doggo.
  • A more straightforward example comes from the Pacifist route's Final Boss, in which saving the Lost Souls who happen to be your friends requires you to use almost every gimmick the main bosses threw at you, such as jumping over obstacles with the blue SOUL. In addition to this, you also have to avoid familiar attack patterns which depend on who you're trying to save.
• Final First Hug:
  • If you spare Toriel, she hugs the protagonist before they part ways.
  • Also with Asriel if you choose to comfort him in the Pacifist ending.
• Final Speech: All the major bosses deliver one after you deal the killing blow to them.
  • Toriel:
    • On a neutral run, she encourages you to continue through the door out of the Ruins and not to let Asgore take your soul, and asks you to be good.
    • If she is killed in the cruelest way possible (attacking her after she stopped fighting and Spared you), she laughs at her own foolishness for having tried to protect you and says that you're no different from the other monsters beyond the Ruins.
    • If she's killed on a No Mercy run, she simply asks in shock if you truly hated her so much.
  • Papyrus:
    • On a neutral run, he'll joke that at least he still has his head, even as you cut it off.
    • On a No Mercy Run, he'll tell you that he still thinks that you can do better and that you can still be a good person if you try.
  • Undyne:
    • On a neutral run, she'll yell fiercly that she's not giving up and that she refuses to die like this, even continuing to weakly throw a few more spears at you before her body completely gives out from the strain.
    • On a No Mercy run, she'll triumphantly tell you that even if you killed her, she's bought time for the rest of the Underground to evacuate and for Asgore to absorb the SOULs and gain enough power to stop you.
  • Mettaton:
    • On a neutral run, he'll tell you not to worry about him and that even though it really looks like he's dying, he's only a robot and Alphys can repair him, as well as that he was glad he got to perform for a human even if he never got to become a star on the surface.
    • On a No Mercy run, he'll comment that you must not want to be part of his fan club.
    • If you halt a No Mercy run at the last moment before fighting him, he'll say that he can tell you didn't strike him down with complete hatred, and is glad to see that you won't destroy humanity or hunt down Alphys like he had feared you would.
  • Asgore: On a neutral run where Flowey doesn't kill him first and he kills himself so that you can take his soul, he'll regretfully tell you that he's sorry he couldn't give you a happy ending, but that you going free is what his son Asriel would have wanted. ^note He clearly has no idea what his son wants at this point.
  • Sans: He'll say that he warned you what would happen and slowly staggers off-screen, saying that he's going to Grillby's. He then asks Papyrus if he wants anything before you hear the sound of him turning to dust.
• Fission Mailed: The game pulls this a few times, but especially towards the end of the Neutral Route, where you are required to get a bad — though not the worst — ending^note you can get the third-best ending if you do as much to obtain the True Pacifist ending as the game will allow you to on your first playthrough. See also Death Is a Slap on the Wrist — the worst you will get for dying is being put back at the last SAVE checkpoint you visited and you may lose some money.
• Flawless Victory: If you dodge all of the names in the special backer credits, you'll gain access to the Developer's Room.
• Flower Motifs: Golden Flowers, a.k.a. Buttercups, are a symbol of memory and death — they are the flowers from their village that the first fallen human wanted desperately to see while on their deathbed, and buttercups are what they used to poison themselves with. They are found in the Royal Gardens (where you confront Asgore, who you must kill and take the soul of to leave the Underground), in Toriel's house (where they are heavily implied to be kept to honor the memory of her two dead children), the entrance to the Ruins (what cushions the player's fall when they enter the symbolic 'underworld' of the game), and the dump (what Flowey uses to save the player from falling to their death after remembering the first meeting with the Fallen Human in similar circumstances). And of course, Flowey himself is one — a creature created after Asriel's death with all his memories but nothing else.
• Foolish Sibling, Responsible Sibling: Subverted with Papyrus and Sans. Papyrus appears to be an ambition-minded skeleton dedicated to serving the royal guard, while Sans only seems interested in pranks and loafing. The reality is that Papyrus' attempts to be serious and mature makes him come across as quite goofy. He also doesn't have a single mean bone in his body; Papyrus is incapable of actually hurting anyone and consequently isn't cut out for joining the royal guard. Meanwhile, Sans secretly spends a lot of his time trying to keep his brother happy and is quite cynical and melancholic beneath his goofy surface, and he hides his own problems to not worry his brother. If the player kills enough monsters, he eventually attempts killing them, and unlike his brother, he will not show any mercy.
• Foregone Victory:
  • Until his boss fight proper, it's actually impossible to face any major consequences from Mettaton's challenges. Either Alphys will save you regardless of what happens, or it's set up so you can't actually lose. Mettaton later reveals that Alphys did this on purpose so she could be involved in your adventure.
  • On the No Mercy path, it is impossible to lose to Mettaton NEO. Not only does he die in one hit like most other bosses along this route, but he does not take any action at all and therefore cannot hurt you.
  • The same goes for Papyrus on No Mercy earlier on, as he immediately spares you and doesn't bother to fight you at all (unlike Mettaton NEO, Papyrus can be spared, but that obviously aborts the No Mercy run). Attack or spare him, the fight is over as soon as it starts. Even on the Neutral and Pacifist routes, Papyrus will never actually kill you (locking you in his easily-escapable shed instead) and will offer to let you outright skip his fight if you lose to him three times, so you don't actually have to be able to overcome his challenge in order to continue the game (but if you're aiming for one of the Neutral endings where Papyrus is dead, you'll have to fight and kill him the hard way).
  • Even before Papyrus, Toriel also refuses to kill you and will actively avoid hurting you when your HP is low enough, making for an obvious Easy Level Trick and letting you just beat her to a pulp or stall her out until she decides to let you pass. Undyne is the first major boss who requires you to actually earn your victory over her.
  • The true ending's final boss is impossible to lose to. You are so filled with DETERMINATION that when your health depletes, your SOUL will split in half... then come right back together again with the words "But it refused".
• Foreshadowing: As a story-based game, Undertale has its own page for this trope.
• Forgiveness:
  • In a True Pacifist Run, you forgive all of the Boss monsters that attack you, including the hotblooded ones like Undyne. Undyne lampshades this at the end of the game, that all the Boss monsters except Papyrus (and Toriel) have tried to kill Frisk.
  • Zig-Zagged with Toriel and Asgore. She's still angry with him for declaring war on humans in the Underground and killing six children that she had tried to protect, since he only needed one soul to cross the barrier and obtain six more. He doesn't blame her one bit for feeling this way. On the other hand, she does save him from you in the True Pacifist ending and they work together at a school in the Golden Ending.
• For Your People, By Your People: Parodied with the Spider Bake Sale, which offers baked goods made "by spiders, for spiders, of spiders!"
• Four-Philosophy Ensemble: The main monsters you can befriend can count. This is evident if you research their behavior in all three paths to the different endings.
  • The Optimist: Papyrus. His naive yet kind nature makes him the most friendly of them. Hot-headed and rather self-centered, but in a good way, Papyrus is also loyal to you once you befriend him. He is one of the few that even in a No Mercy Run will say upon his death that he believes that you can be a good person, showing just how deep his optimism goes.
  • The Realist: Alphys. How she acts depends on which path you're taking. She'll either consider you friendly and a kind person or such a nightmare that she avoids having to meet you in person and helps all the monsters to escape from your reach.
  • The Cynic: Undyne. The foil to Papyrus, once she meets you in person, she blames your unwillingness to die and give your SOUL as the reason why everyone is still stuck in the Underground. She mellows out significantly if you befriend her.
  • The Apathetic: Sans. His knowledge of the ability to SAVE left him broken and finds reaching to the Surface no longer satisfying. He will break this way of thinking to battle and try to stop you in the No Mercy run, however, and is implied to be in a better state of mind at the end of a Pacifist Run as well.
• Four-Temperament Ensemble:
  • The four monsters you befriend in the Pacifist route. Papyrus (sanguine), Undyne (choleric), Alphys (melancholic), and Sans (phlegmatic). The Human Child is the leukine.
  • The four ghosts fit too: Dummy (phlegmatic), Napstablook (melancholic), Mad Dummy/Mew Mew (choleric), and Napstablook's disappeared cousin Mettaton (sanguine).
  • The royal family can count as well: the King Asgore Dreemurr and the former Queen, Toriel are both on the verge between melancholic and phlegmatic, the Fallen Prince Asriel was choleric, and the First Human appears to be sanguine.
• Fourth Wall Psych: There are a few moments where the game comes dangerously close to being a RPG Mechanics 'Verse but doesn't quite cross that line. Many of the game's aspects that most players find part-and-parcel for RPGs (i.e. saving and loading, experience points and levels, the Silent Protagonist) are bluntly pointed out to the player, but are also given in-universe explanations (Determination, Level of Violence, Symbiotic/Demonic Possession), and the game's meta-story is an exploration of these concepts. Notably, the Pacifist ending involves inducing this, finding out about an in-universe person for Flowey to be talking to when he addresses the person controlling Frisk and turning his thoughts towards them so he can properly sort through his own emotional baggage.
• The Fourth Wall Will Not Protect You:
  • Upon defeating Asgore, Flowey steps in to absorb the six human souls, which causes the game to abruptly quit. Upon starting the game back up, things only go downhill from there.
  • Also part of Flowey's M.O. since he also has the power of DETERMINATION. He routinely jabs at you for cruel actions and laughs if you try to use the save system to wipe them clean. His biggest threats to you are also to destroy your save file and reset the game to the beginning.
  • The game dives into this full force at the end of the No Mercy run. The boss tries to convince you to stop playing, and things get even worse in the ending itself. And it gets even worse than that if you try to restart the game after that.
  • This even managed to sneak itself into the merchandise; if you buy Fangamer's "determination" bundle, Flowey will appear and offer you a one dollar discount. It's treated like a Deal with the Devil: if you accept it, the postcard that comes in the box, which is normally a detailed photo from one of the Pacifist endings◊, is replaced with the Soulless Pacifist ending's version in horrifying detail◊. Hope that one dollar you saved was worth it.
  • And if you thought that the this abuse of the fourth wall is resigned only to what the author controls, it somehow manages to break the fifth wall(?) by addressing people watching the game being played. During Flowey's monologue in New Home, he'll express distaste at people doing the genocide run "because they need to know" for trying to justify their actions with a shallow excuse, but say that even worse are the people who watch a genocide run "because they need to know", i.e. let's play and stream watchers. The game is so meta, that it has the foresight to address the audience behind the audience and judge them for it.
  • Inverted in the genocide route, as some characters will express fear of the player. For example, after Flowey's monologue in New Home, he realizes that he's the player's next target. The final boss also knows about the player, and it is revealed that he has lived most of his life simply accepting everything the player does, knowing that they will eventually reset anyway.
  • Sans' fight in the No Mercy run isn't designed to stop the player character. It's designed to stop the player. He knows that the player character has limitless resets and lives to spend on this and that they'll win eventually if you keep trying, so his goal is to make you so frustrated that you quit and try something easier, like the pacifist or neutral runs.
• Freeze-Frame Bonus:
  • If you die to Toriel (which you have to actively try to do), she'll show a unique sprite for a split-second depicting her shock at having killed you before you see the game over screen.
  • If you backtrack in some areas, you'll see a quick flash of... something disappearing into the ground. It's Flowey, who's stalking you over the course of the game and observing your actions before picking the best time to strike.
  • It's possible to talk to the Snowdin innkeeper while the screen's still fading to black after deciding to stay at her inn. Her response, in which she says, "What? No, you can't get a second key!", is this, as you wouldn't be able to read it otherwise due to the speed of the transition.
  • In the game's release trailer, Undyne is shown hunting the player, captioned with "And strong enemies." "..?" is tacked on just before transitioning to the next scene, as she can be befriended over the course of the game.
  • If you pause the release trailer right at the beginning of the "probably not actual gameplay footage" segment, the tree in the background has one of Flowey's toothy grins on it for no particular reason.
  • In the Nintendo Switch release trailer:
    • At 0:21, Temmie can be seen under the pink ribbon on Mew Mew's staff.
    • At 0:46, the caption "ALMOST NO NEW CONTENT!" changes to "ALMOST NO MEW CONTENT!"
• Friendly Neighborhood Vampire: Apparently, humans and monsters lived in harmony once long ago, and do again at the end of a Pacifist run. Think about all the monsters you meet (including ghosts, skeletons, wolf-people, and giant talking octopi), and think of how people would react.
• The Friends Who Never Hang:
  • Papyrus's interactions with Alphys are limited: Beyond mentioning her as the one who designed the colour tile puzzle in Snowdin and showing up during Alphys's date to cheer her up, they don't interact that much.
  • Sans and Undyne interact even less with each other, the only time where they are seen together is when Undyne is chasing you through Hotland, seeing Sans sleep and getting annoyed for not helping her, in some of the Neutral endings where both of them survive, and in the Pacifist ending when all the main monsters are together.
  • Also, Sans and Alphys never interact much, though late in the game it is revealed that they do know each other, since she is familiar with his humor, but whatever this connection is, the game doesn't elaborate on it.
• Frying Pan of Doom: The Burnt Pan weapon, which is even more useful on a Pacifist Run since wielding it causes consumable healing items to restore 4 more HP than normal.
• Fun with Acronyms:
  • EXP and LOVE, of course! According to the Judge, Sans, they actually stand for EXecution Points and Level Of ViolencE.
  • In the Ruins, one Froggit that knows about timed hits comments on F4's function, wondering if it stands for "four frogs", even though there's only two other Froggits in the room with it. The fourth frog actually exists, but it's tiny and you have to interact with a specific portion of the back wall to find it.
• Funny Animal: A large chunk of the monsters are anthropomorphic animals (goats, cats, bunnies, fish, dogs, etc) with human personalities and clothing.
• Furry Confusion:
  • A rabbit lady in Snowdin has a small, non-anthropomorphic rabbit on a leash as her pet. A rabbit guy nearby finds this a little disturbing. The Playable Epilogue reveals that leashed rabbit is actually her little brother.
  • Catty also talks about how she wants to buy a cat at some point, despite being a big humanoid cat herself.
• Furry Female Mane: Gender-Inverted with Asgore and Toriel. While Toriel doesn't have feminine hair, and her only Tertiary Sexual Characteristics are eyelashes, Asgore sports long viking-like blonde hair and a beard to highlight his manliness.

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