Due to the sheer volume of spoilers, all of them are unmarked in this page. You Have Been Warned.

It was a LEGEND of HOPE. It was a LEGEND of DREAMS.
It was a LEGEND of LIGHT. It was a LEGEND of DARK.
This is the legend of DELTA RUNE.
The power of describing Deltarune here shines within you.
Deltarune is an episodic Role-Playing Game by Toby Fox for the PC, Nintendo Switch, Nintendo Switch 2, PlayStation 4, and PlayStation 5. A successor and "parallel story" to Undertale, Fox describes it as, "a game you can play after you complete Undertale, if you want to."
The town of Hometown is a perfectly normal and charming little sunny suburban community where pretty much all the residents are monsters living peaceful and mundane lives. You, the player, are placed in the role of Kris, the only human resident of the town. Otherwise, Kris lives in a perfectly normal house with their rather overprotective and snail-loving adoptive mom Toriel, waiting for their older adoptive brother Asriel to return from college.
One day at school, Kris and resident bully Susie are tasked to get some chalk from the supply closet. Said closet turns out to hold an otherworldly dimension known as a Dark World inside it. They form an uneasy alliance to protect themselves against the Darkners that inhabit the place, and soon they meet the Prince of Darkness, Ralsei, who tells them that the three are the fabled "Delta Warriors" who are prophesied to save the world.
But the Dark World, as well as the ones that come after it, is full of many opponents and oddball characters, as well as the continued question of what kind of heroes they will be, and whether the choices they make matter or not. And with it becoming more clear that we are headed to darker areas, it puts to question, what's truly going on here?
Gameplay fundamentals have changed little from Undertale (with Action Commands and the ability to non-lethally defeat enemies being core parts of the system), though it has changed to accommodate three party members, each with their own classes and abilities. The game also introduces a TPnote system for combat, allowing the player to build up a special gauge by guarding, attacking, or grazing bullets, which can then be spent on certain ACTs or spells or converted into money after the battle ends.
Currently, there are seven planned chapters. Initially teased on the Undertale Twitter account on October 30, 2018, the first chapter was released for free a day later on Halloween, in the guise of a "survey program." The second chapter, also free, was released on September 17, 2021. The first two chapters serve as the game's demo. Chapters 3 and 4 were released as a paid bundle alongside the Nintendo Switch 2 on June 5, 2025, and the remaining chapters will be free additions to this bundle. Chapter 5 is scheduled for sometime in the year 2026
, and the others on currently unspecified dates.
The game is available from various digital retailers, as well as its official site.![]()
SELECT THE TROPES THAT YOU PREFER.note
- 555: In Noelle's hidden blog, Berdly leaves a few comments. His username has his phone number in it, which starts with 555.note
- Action Commands:
- When FIGHTing, a bar comes from the right side of the screen, and the player has to press a button when it reaches a box on the left side; the closer the bar is to the box, the greater damage the attacking character deals, with a perfect attack turning the bar yellow and making a special sound. When more than one character attacks in a turn, multiple bars appear, with some bars being synchronised with another.
- Select enemies and bosses include ACTs that require the player to complete various minigames in order for them to be effective, such as lining up Bloxer segments, gauging how Susie throws Kris or Ralsei at a target, blocking pop-up ads through button mashing, and timing when a cage drops to catch swarms of maice, among others.
- Aerith and Bob:
- Considering that most returning monsters have made up or at least unusual names (Toriel, Undyne, Alphys, Asgore, etc.), it's a bit weird to see a lot of the newer ones have names like Rudy or Alvin. In particular, the current roster of playable party members as of Chapter 4 consists of Kris, Susie, Noelle... and Ralsei.
- Names among the Darkners include Lancer, Rouxls Kaard, King, Queennote , Spamton, Mr. Ant Tenna, the Original Starwalker... and Mike.
- After-Combat Recovery: After combat ends, any downed party members will be revived at 12.5% of their maximum HP.
- All-Cheering All the Time: Catti and Catty's mother constantly treats everything her daughters do as if it was a sporting event, no matter how inappropriate it is to do so.
- All Drummers Are Animals: Downplayed. The rhythm minigame in Chapter 3 has the party playing as a rock band. Susie, the most unhinged member of the trio, is shown going to town on the drums, and then being immediately eliminated due to not being on-rhythm. However, she plays perfectly on-rhythm during Tenna's boss fight and like a novice if replaying the minigame in the Green Room or Castle Town.
- all lowercase letters: The game's title is stylized this waynote , in contrast to Undertale's all-uppercase title.
- All There in the Manual: A lot of the odd interactive pages on the game's official website are not just teasers for Chapters 3-4, but also serve as hints for the player to find the hidden secrets in those chapters:
- The Green Room
page will take a user to an empty "romb" page if Ramb's shop is clicked on, which will take the user to a page titled "No one will shed a tear for him" (a line said by a Pippin if the player takes the Normal Route for Chapter 3), which will eventually bring up Seam's quote about not getting the crystal without the Shadow Mantle. All of this is to point the player towards getting into the S-Rank room and doing the Sword Route, which will avert the sequence shown. - The "rarecats
" page will take the user to the "windows
" page if an angel cat is clicked on, which is a recreation of the secret window hallway found in the Chapter 4 Dark World. All the pages are rearrangements of "lost where the forest would grow" and "the poor children", referring a prophecy spoken by an Organikk in the room that the hallway can be accessed from. Accessible from these pages is the "therapy" page which will eventually display the Man's tree, hinting at how to receive the Egg for that chapter.
- The Green Room
- Alternate Reality Game: The Spamton Sweepstakes charity event in 2022 is not this, at least not in the eyes of Toby Fox. While the Sweepstakes website
featured a number of hidden links
to various pages, a blog post
written by Noelle, which talks about the in-universe stand-in for Deltarune, indirectly says the Sweepstakes are not considered to be an ARG due to the "lack of puzzles, and not leading to anything". True enough, all the hidden websites do is give you a few gags and hints towards the lore of future chapters. - Ambidextrous Sprite: Kris and Berdly are aversions of this trope when they're in the Dark World, with their respective cape and eyepiece only showing up on one of their side sprites.
- Ambiguous Situation:
- The exact nature of the Dark Worlds isn't exactly clear. Chapter 1 suggests and Chapter 2 confirms that Darkners are mundane objects brought to life by the Dark Fountains. Despite this, Darkners imply they've had long relationships with both each other and Lightners. While the Lightner relationship could simply be the viewpoint of an old toy whose owner outgrew them, their relationships with each other seem impossible to have been constructed retroactively, as multiple characters know of Queen's existence before the Cyber World was even created. Chapter 3 clarifies that these relationships are based on the objects they're formed from, where they're taken in the Light World, and how they're used by Lightners, with the implication that even before the Dark Worlds are formed, these objects have "personas" and "memories" of who interacted with them and in combination with other objects. Chapter 4 shows what happens when that object is bound to a deceased person with Gerson, who was brought back to life as a hammer-wielding hero of justice while fully aware that he's long dead in the Light World and is actually his old hammer thus used the opportunity to write his son some words of encouragement.
- Towards the end of Chapter 2, the save point that appears after Queen's first boss fight tells you that you are filled with "a certain power". Soon, we see Queen talking about the Lightners' power to utilize Determination, effectively confirming that it exists in this game. However, the game continues to refer to Kris being filled with "a certain power", leaving it uncertain whether that power is indeed Determination.
- A bunny monster in Chapter 1 asks Kris if it "hurts to be made of blood", which would suggest that monsters don't bleed. However, Susie is shown to bleed in Chapter 4 when she smashes the penultimate verse of the prophecy with her bare fist, leaving it ambiguous whether the bunny is just wrong or Susie is a different type of monster altogether. Of course it should be mentioned that Susie earlier that day drank almost an entire large bowl of red juice which was joked about looking like blood, and Undertale implied that whenever monsters eat/drink anything, their entire body essentially becomes a "container" for what they ate. In other words, Susie likely could've just been "bleeding" juice.
- The very existence of the Weird Route and its potential impact on the story. Toby Fox stated that there would be only one ending, yet all evidence points to the Weird Route taking the story completely Off the Rails, with Ralsei even fearing that things may head to a worse ending than what the Prophecy foretells. This throws some ambiguity on what Toby actually interprets to be an "ending" by meta standards.
- Angels, Devils and Squid: The Delta Warriors are angels, the Arc Villains of each chapter (King, Queen, and Tenna) are devils, and the Titans are squid. Whether the Roaring Knight is a devil or a squid is up to interpretation as of Chapter 4.
- Animal Motifs: Cat and dog imagery becomes more prevalent and oppositional as the game goes on.
- Kris is associated heavily with dogs, being frequently referred to with dog imagery by others around Hometown, especially Noelle, howling in response to certain questions, and dressing up in a dog costume during one screen in Chapter 3. More seriously, their Conflicting Loyalties, desire for "freedom," and being metaphorically bound by the SOUL call to mind a dog straining against a leash.
- Cats are associated with the more ominous and "creepypasta" aspects of the story, most notably FRIEND, a grinning figure that resembles a feline version of Endogeny from Undertale. Noelle's blogposts about her experiences with the game Cat Petterz is the first hint that Hometown has dealt with some strange occurrences well before the events of the game itself. Even more subtly, the "knockoff" videogame controller in Kris's bedroom is repeatedly mentioned throughout the chapters and becomes central to Chapter 3's Sword Route, which is full of unsettling imagery including the most prominent appearance of FRIEND — and one of the most well-known manufacturers of third-party controllers is Mad Catz.
- Animate Inanimate Object: The Darkners are a variant. Though they are fully-animated monster people inside the Dark World, they are suggested in Chapters 1 and 2 and confirmed in Chapter 3 to correspond to objects absorbed by the Dark Fountain. Chapter 1's Darkners become toys, cards, and chess pieces from a school storage closet in the Light World, Chapter 2's correspond to the hardware and software found in the library's computer lab, Chapter 3's correspond to the disused TV (which becomes Tenna) and the various channels and programs on it, and Chapter 4's correspond to the various items around the church.
- Anti-Escapism Aesop: Played straight and inverted. The Dark World is a clear metaphor for escapist hobbies like games, the internet, and television. The apocalyptic Roaring will occur if Dark Worlds spread too wide, much as one cannot prioritize escapism over your actual life. On the other hand, the story doesn't just portray moderated escapism as acceptable, but vitally important for the characters to escape the social expectations of the world they live in and explore new sides of themselves. Susie, for instance, goes from a maladjusted bully lashing out because that's what people expect of her into a caring big-sister figure once she's introduced to her first positive relationship with Lancer. This fits with how Dark Worlds and darkness in general are associate with dreams: One cannot live in dreams, but that doesn't mean you should or even can stop having them.
- Anti-Frustration Features:
- One of Undertale's many commentaries on role-playing games was defying We Buy Anything, as the various shopkeepers would not buy the player's junk since they didn't need it; you could only sell items to the one shopkeeper dumb enough to accept your stuff. Since Deltarune is closer to a traditional RPG and money is more useful, it drops this joke and lets you sell your stuff to any shopkeeper except Spamton, who replaces the "SELL" option with the "BUY MORE!!" section; which is just the first Buy option again.
- The game notices if you're playing through a chapter having already completed it. Should you do so, you're given the option to skip the chapter's opening by going back to sleep, which has Kris wake up right where the action of the chapter starts.
- In the original "SURVEY_PROGRAM" version, if you make it to the Dark World in less than 8 minutes, you get the Wrist Protector, which lets you skip text by holding the menu button. It also doesn't appear in the inventory. Starting with the Chapters 1&2 Demo, the Wrist Protector is removed in favor of making text-skipping an inherent feature.
- Similarly to boss fights in Undertale, failing a boss fight and retrying it will skip the intro cutscene. Instead, the boss immediately does their Evil Laugh and the fight begins.
- The boss fights against most non-recruitable bosses such as King and Rouxls Kaard give the same result whether they're defeated through violence or ACTing. In Berdly's case, defeating him through FIGHTing slightly changes his physical state, but doesn't change the route or gameplay. The sole exception to this pattern so far is the first fight against Spamton on the Normal Route: defeating him violently locks the player out of his sidequest and Chapter 2's Shadow Crystal.
- The first time you get a Game Over, you get a few screens of dialogue. It's changed to a simple "want to continue?" yes/no question every time you die after that until you quit the game. Alternatively, Button Mashing will skip the game over screen and just automatically continue.
- Just like in Undertale, there are various points where the game autosaves so that if you die, you don't have too much to do again if it's been a while since you last saved. This is also useful if you're doing a no-save run.
- Each chapter uses its own set of save files; this means you can skip to a later chapter even if you haven't completed an earlier one, as well as play each chapter individually instead of starting from the beginning of the game. However, the default saves will not assume "perfect play", meaning that starting from Chapter 3, the default saves will lack some recruits, meaning you'll miss out on some extra storage slots and certain events in Castle Town. You can also continue from any save file you've completed the previous chapter on, allowing you to keep any items you've obtained and dialogue options you've triggered on that file.
- The Superboss fights end with the player receiving a weapon or armour depending on how the boss was defeated. Should the player's inventory be full, however, the item will be stored in a chest nearby so you can pick it up later. Additionally, if you complete the chapter without defeating the hidden boss, you can still collect their Shadow Crystal and weapon/armor from the hole to the left of Castle Town, as long as you have previously defeated them in that save file.
- For the secret Egg rooms in Chapters 1 and 2, the exit is to the south, but you move east and west to trigger the room, preventing you from accidentally leaving as soon as you enter. The Chapter 4 room is the reverse; the exit is east, but you get there by moving north and south. The Chapter 3 room is an exception, as it is found in a completely different way than the others.
- When Chapter 2 introduced Recruits and their permanent missability, it and future chapters also provide a way to let the player know if they have unrecruited enemies, just in the chance the player missed something hidden. Chapter 2 has Trashy just before the final fight with GIGA Queen, Chapter 3 has a list of remaining employees in the Green Room, and Chapter 4 has a bell that "judges" the player's status.
- In Chapter 3, dying during a board segment allows you to continue at the cost of forfeiting all of the Points you have acquired. Since Points in this chapter replace the typical currency, and are needed to purchase healing items, dying to the Mini-Boss while having 0 Points will have Tenna take pity on you, and instead give you 2 powerful healing items for free to give you a better chance of moving on.
- During the Sweet Cap'n Cakes fight, you have to play through several rounds before unlocking S- and R-Action, which are required to win the fight, but when Kris is down, the fight skips to the end immediately. This initially had the unfortunately side-effect of making speedruns a Luck-Based Mission, as Kris does not get randomly targeted by their attacks as often as Susie and Ralsei when they're at low health, so knocking Kri out early on in the fight is entirely reliant on RNG and can cost you a run. A later patch added a hidden feature to mitigate this issue: if you use DanceX on K_K specifically on your first turn (something a regular player is unlikely to do since Sweet is first in the order), their attacks will always target Kris.
- If you die enough times to the Titan at the end of Chapter 4, Cuptains will climb to where you are and offer you free healing items.
- Anti-Grinding: Darkners run away instead of dying when defeated in Deltarune (outside of the Weird Route, and even then they still technically don't give XP), so the party members can never receive XP, and their LV and base stats only go up upon sealing a Dark Fountain. Starting with Chapter 2, the heroes can gain stat bonuses for the current chapter by FIGHTing Darkners, but this has its limits and also renders the defeated enemy Lost, preventing them from being recruited to Castle Town.
- Apple for Teacher: Toriel has an apple on her desk in her classroom. Checking it tells you that it's "some kind of teacher food". At the end of Chapter 2, the apple is replaced with an orange, with the flavor text wondering if it's safe for teachers to eat. In Chapter 4, it's been replaced with a pear, which the Flavor Text refers to as an insulting "substitute teacher food".
- Arbitrary Headcount Limit: Kris can only have up to two extra party members. Lancer joins the three-member Delta Warriors in Chapter 1, but just slides to the side of an enemy-free path right up until he leaves. Noelle only joins the party after Susie and Ralsei leave in Chapter 2, and while she stays after the groups combine, she conveniently gets preoccupied at any point where the Delta Warriors could get into an encounter, right up until she gets separated from them for the rest of the chapter. Played with in Chapter 4, where Gerson can randomly stumble into certain fights and you can perform ACTs with him.
- Arc Number: "1225" — or Christmas Day — which appears very frequently alongside mentions of or allusions to Dess.
- In Noelle's room in Queen's Mansion, there's a calendar where each month is the last month, and each day is the 25th (December 25th, 12/25). This implies that the phrase "December Holiday" was a frequent search topic for her.
- Sealing the Cyber World's Dark Fountain with Noelle's Silver Watch equipped on Kris turns it into a Wristwatch once you return to the Light World. Checking the watch reveals that it is "stuck before half past noon", implied to be 12:25.
- Noelle's username
in her Character Blog, revealed via the Spamton Sweepstakes, is holidaygirl1225. - In Chapter 3, 1225 is the passcode of one of the parental locks that guards the room where Tenna keeps Toriel hostage — specifically, it's the parental lock on the music video channel that Dess used to watch in secret.
- Also in Chapter 3, if you spend exactly 1225 points on the B-Rank room's Ball Machine
, the background music will halt and a secret passage opens in the Ball Machine. Entering it sends Kris to a maze where they can find a smaller blue Ball Machine, whose capsule contains a "small, dark, triangle" hard as lacquer... that causes Kris's hand to disappear when they try to take hold of it. - In Chapter 4, while searching for clues in Noelle's house, Kris finds one of the codes for the Hometown shelter in Dess's guitar. While we don't see the whole code due to Kris tearing out their SOUL, the first three numbers are 122, implying the whole code is 1225.
- Arc Symbol: The Delta Rune itself, consisting of a circle, two wings, and three triangles below it. It's one of the secret codes to the shelter, as well as a symbol of the prophecy.
- Arc Words:
- When using certain save points, the words "shining" or "power" appear in the flavor text, paralleling Undertale's "filled with determination". Notably, the word "determination" doesn't appear on any save point, even after Queen namedrops the concept in chapter 2.
- The phrase "your choices don't matter" and variants thereof show up a lot in Chapter 1; this is contrasted to the message of Undertale quite severely, which was that your choices really do matter quite a lot.
- Every keyword related to W. D. Gaster shows up either in-game or on the Twitter lead-up to chapter releases. Things like "Very, very interesting", "Darker, yet darker", "Don't forget", "feedback" from nonsensical yet ominous surveys and variations of "be seeing you soon" or "you'll meet somebody soon".
- The phrase "The air crackles with freedom" appears as flavor text for three superbosses. Against Gerson, the phrase is meaningfully altered to "The air crackles green with freedom". "[It's] for you" is also a phrase that's repeated in each battle, through either dialogue or flavor texts.
- The Weird Route has "Proceed". In Chapter 2, when you come across the first Annoying Mouse Room, you'll be given the option to say "Proceed". Doing so enough times will cause Noelle to rush past the puzzle. You'll do this again for the second one, except this time she freezes the puzzle, but when you reach the third one, she will automatically freeze it without you telling her. When encountering Berdly, you'll be given the option to say "Proceed" again. Choosing this dialogue option whenever it comes up is required to continue the Weird Route and it receives several lampshades from both Noelle and Berdly.
- "Become stronger" is regularly used in a similar manner to "LV/LOVE" from Undertale by having the player (or rather, the player making Noelle) kill everyone in order to unlock secret paths, in both the Weird Route and Chapter 3's Sword Route, the latter of which also nods at the former.
- Going "nowhere" also starts to appear in Chapters 3 and 4, whenever Kris is prompted about a direction or location. Depending on your route, either it's tied to them feeling surrounded due to conflicting loyalties between the Roaring Knight and the other Delta Warriors (Normal Route), or feeling helpless (Weird Route).
- "Roots" is a minor but mysterious one that appears in Chapter 4. In a hidden room in the Third Sanctuary, there's a fragment of the prophecy that shows a house in between two trees and the word "ROOTS." It's also one of the words that Bibliox has you spell check. Roots also appears on the soundtrack as the title of "Digital Roots" and "BIT ROOTS
", the latter of which plays in MANTLE's ominous final dungeon. What it actually means is yet to be explained.
- Are You Sure You Want to Do That?: After returning to the Light World from the Dark World, your Dark World inventory is represented as a "Ball of Junk". If you attempt to drop it, the game will warn you that you don't want to do that — and if you insist, your Dark World main inventorynote will be wiped out.
- Art Evolution: The sprite animation in this game is more fluid, detailed, and dynamic compared to Undertale, which saved its most detailed stuff for very key moments. This is part of the reason for the game's lengthy development time.
- The Artifact: While giving his thoughts on the demo
, Toby Fox admitted he found the ACT/FIGHT system a lot less meaningful due to his choice to only include one ending for the game. Chapter 2 introduces more factors affected by whether the party uses violence or mercy, and adds additional strategic elements to ACTing via allowing Susie, Ralsei and Noelle to ACT independently of Kris, though outside of the Weird Route (which is deliberately distanced from typical actions and is ambiguous as to what it implies for the rest of the game) they're still kept relatively minor. - Artificial Insolence: Until you defeat her and Lancer in a battle and she subsequently has a Heel Realization in Card Castle's dungeon, Susie will ignore any commands given to her and will blindly FIGHT the top enemy no matter what. Even after she's come around, she'll still refuse to equip her starting weapon, the Mane Axe, if she's already held a stronger axe, saying, "I'm too good for that", and will refuse some armor point-blank (e.g. ribbons) because she dislikes how it looks.
- Ascended Extra: In Chapter 1, Noelle was just another one of Kris' classmates. Then in Chapter 2, she enters the Cyber World, her relationships with Kris and Susie are explored, and it's implied her family has a lot to do with what's going on in both the Light and Dark Worlds.
- Ascended Fanon: Explicitly played with, as the charmingly domestic Hometown lifts elements common in fan works, such as Asriel surviving what happens to him in Undertale's True Pacifist ending (primarily because the events of Undertale never happened to begin with). But it also subverts a lot of those expectations as well, with many relationships from the previous game nonexistent, such as Undyne not knowing who Alphys is.
- Ascended Meme:
- Kris' love for chocolate is mentioned in multiple places by the narration and people who know them well, with Toriel even having to hide chocolates from them so they don't eat them all at once. Being a Composite Character of Frisk and Chara at least in design, this appears to be a reference to the Undertale fanbase having fun portraying Chara, whether good OR evil, as a ravenous chocolate-loving maniac based off a single line in the game.
- Ralsei's Valentines 2024 card mentions Susie wanted to roll up all the valentine paper into a giant tube. Ralsei indignantly refuses her pestering to pretend to smoke out of it, referencing the "Ralsei smoking a fat blunt" meme.
- In Chapter 3, after getting the Shadow Mantle, Susie mentions Ralsei got mad at an arrow-based video game they were playing together, with Ralsei mentioning he was "not very chuffed, by that dart". "Chuffing a dart" is slang for smoking, yet another reference to the "Ralsei smoking weed" meme.
- In Chapter 4, Kris can command Ralsei to "light up" when facing a number of enemies, like Balthizard. It's always completely innocuous (Ralsei just uses fire magic to stoke actual lights), but the flavor text always leaves it at "Ralsei lights up!" To nonspecifically "light up" is, again, slang for smoking.
- The sprite of Noelle grabbing Berdly for proclaiming his love for Susie has her grab him by the chest, but most fans mistook her as grabbing his neck and strangling him. In Chapter 4, she does mention she'd convey how she doesn't want to just do everything Berdly tells her by grabbing him by the neck and screaming at him, which genuinely shocks Susie.
- In Chapter 4, it's revealed that Noelle has a picture of a "green dog puppet" for her computer wallpaper. This is likely meant to be GIR from Invader Zim, which became associated with Noelle after SiIvaGunner released a popular remix of "Fields of Hopes and Dreams" which featured her in a GIR hoodie.
- During the hiatus between Chapters 2 and 3&4, a large chunk of the fanbase latched onto "Friend Inside Me", a theory involving an Expy of Woody from Toy Story being a secret boss in future chapters, based entirely on a comment Toby made about a cut cowboy minigame, and a several year-old Tumblr shitpost
of Toby's where he remixed the song "You've Got A Friend In Me" to sound way creepier, with the only lyrics being "Friend Inside Me." This theory was promptly turned into a meme. Come Chapter 4, and the Mike that runs the Jongler minigame has a cowboy hat on, and if you get the highest score in said minigame, the first Mike will scold you for making people think Mike is a cowboy, then shout that he has "friends on the inside". - The sprite of wide Susie was popular for use of a meme in which her widened sprite says "Dammit Kris, where the hell are we?!". In Chapter 4, if the weapons inventory is full when acquiring the Justice Axe, Susie gets wide and shouts "Dammit Kris, the hell did you get so much stupid stuff?!"
- As You Know: Several characters (especially Toriel) will talk about past events with Kris conveniently conveying information about their backstory to the player.
- Author Avatar:
- Once again, the Annoying Dog appears as Toby Fox's avatar. In Chapter 1, examining the door to the library's computer lab shows him (via dialogue) to be developing the game inside, and he becomes a recurring gag starting in Chapter 2.
- Temmie represents the game's artist, Temmie Chang.
- Battle Theme Music: The game features a large array of different battle themes: regular battles use a fast-paced jazz track called "Rude Buster" for Chapters 1-3 and a more intense arrangement of "Dark Sanctuary" called "From Now On" in Chapter 4, but there are a couple of other tracks for minibosses, bosses, and other situations.
- Chapter 1: "Vs. Lancer", an arrangement of Lancer's theme, for his battles. K. Round's battle theme is the upbeat and not really serious "Checker Dance". The Susie vs. Lancer fight uses a much darker rock track called "Vs. Susie". King's theme, "Chaos King", is a climactic arrangement of "Card Castle". Jevil's theme, "THE WORLD REVOLVING", is a carnival-style track.
- Chapter 2: "A Simple Diversion" is a short chiptune track used for the Punch-Out!! practice battle against Queen. The battles with her at the end of the chapter uses a fuller arrangement called "Attack of the Killer Queen", and "Knock You Down !!" for the one right after. For minibosses, Berdly gets "Smart Race", Rouxls gets "It's Pronounced Rules", and Sweet Cap'n Cakes get "Cyber Battle (Solo)". Spamton's battles use "NOW'S YOUR CHANCE TO BE A" and "BIG SHOT" (the latter when facing his NEO form).
- Chapter 3: "Ruder Buster", an extended arrangement of "Rude Buster", plays during the miniboss battles on the board, and when fighting Elnina and Lanino. "Vapor Buster" is a vaporwave arrangement of "Rude Buster" used when fighting the watercooler. "Burning Eyes" is used for the Shadow Mantle Holder. The final boss themes are "It's TV Time!" for Tenna and "Black Knife" for the Roaring Knight.
- Chapter 4: "A DARK ZONE" for Jackenstein, "Hammer of Justice" for Gerson, "Ripple" for Fake Gerson, "SPAWN" and "GUARDIAN" for the Titan, and "Catswing" for the optional fight against Mike.
- Be Careful What You Wish For: Played for Laughs in Chapter 4. The Church Wafers in the Dark Sanctuary all venerate a statue of an Organikk as their ancient ancestor, wishing they could have met. Later, when the Dark Fountain has been sealed and re-opened, making the 2nd Sanctuary, the script is flipped, with the revived Organikk wishing they could have met the now petrified Church Wafers. In the 3rd Sanctuary, both of them are revived and able to meet... only for the Church Wafers to see the Organikk as a babbling buffoon and threatening to kick their ass.
- Because Destiny Says So:
- Deconstructed as the game's central theme. Deltarune portrays the idea of fate and destiny in a scary and pressuring way. You don't get to choose your character and you don't get to choose how you play the game. Nowhere in the game do you actually have free will or make any impactful choices. Kris repeatedly tears out their SOUL from their chest, seemingly so they can have free will and a choice of their own, even if it's morally-ambiguous, since Kris has goals separate from our own (and many characters make the point that Kris is acting very out of character, implied to be due to the influence of the player on their decisions and abilities).
- However, Chapter 2 shows a loophole — Kris can't make impactful decisions, but the player can cause other people to do so. Specifically, Noelle can be forced into killing every Darkner she encounters, and if you equip the Thorn Ring on her, she gains a lethal ice spell, SnowGrave, that she can use to send Berdly into a coma and go on a horrifying killing spree, which ends with the violent seeming-death of Spamton. Back in the Light World, Noelle says that a voice was telling her to do all those horrible things, which is implied to be the player's voice.
- Chapter 4 introduces the actual words of the prophecy, first mentioned in Chapter 1, which turns out to be way more accurate than Ralsei let on, predicting everything the main characters have been through, including details like Ralsei being called "Toothpaste Boy" by Susie and Lancer in Chapter 1. Indeed, apparently every part of the prophecy always comes true — which is why Ralsei is so desperate not to reveal the whole thing to Susie and Kris, because the penultimate verse is so terrible, Susie puts her fist right through it when she sees it (which also prevents us from learning about it).
- The hidden bosses in Chapters 1 and 2 revolve around this trope; both of them have found some sort of horrible truth about their world that drove them into insanity and believing they don't have any freedom. What separates them is how they react to it: Jevil relishes in it because he believes it makes him able to do whatever he wants with no consequences, while Spamton is horrified and wants to free himself by ascending to "Heaven" (implied to either be the Light World or the real world). The Chapters 3 and 4 hidden bosses, meanwhile, toy with the idea of predestination; the Chapter 3 fight is a Hopeless Boss Fight against the Roaring Knight which you can actually win to an extent, and the Chapter 4 hidden boss is Gerson (a character who doesn't believe in fate) in a friendly match against Susie.
- Big Door:
- There's a large underground shelter in the forest to the south of Hometown. Locked, obviously. The epilogue of Chapter 2 has Monster Kid and Snowy attempt to open it, but to no avail. Chapter 3 ends with the Roaring Knight kidnapping Undyne and retreating into it, and Chapter 4 starts with Susie and Kris trying to find the three codes that open it so they can rescue her.
- Great Doors are a recurring set piece in the Dark Worlds, resembling giant, ornate black-and-gold doors with the Delta Rune above them — they represent doors in the transformed room, and can link to neighbouring Dark Worlds or even provide an exit back to the Light World. Examples include the one connecting Castle Town to Card Kingdom (which becomes permanently locked after Chapter 1), the one Kris and Susie use to exit the TV World at the end of Chapter 3, and the one connecting the 1st/2nd and 3rd Dark Sanctuaries.
- Bigger on the Inside: Dark Fountains made indoors invoke this, creating Dark Worlds that are far more extensive than Hometown itself, let alone the small rooms they're inside of. Cyber World in particular is shown to be large enough to hold an entire city with surrounding outskirts.
- Biting-the-Hand Humor: Like its predecessor, the PlayStation 4 version of the game has trophies purely because they're required. Unlike Undertale's trophies, which are all either comically trivial or related to the Dog Shrine, Deltarune's trophies are entirely simplistic actions such as equipping items, taking damage or inspecting random objects. The unlock requirements are all highly literal to what's said — with "RING" meaning either obtaining one of the rings from the Weird Route or hearing a ring sound, or "OBSERVE THE DUPLICATE" referring to copying a save file, checking the mirror in the Dreemurr household, or watching Kris' game avatar leave the game in the Sword Route. Completing the game up to Chapter 4 without attaining any achievements leaves the Voice astonished and confused, and Toby himself has built up the achievements as a burden for any player to attempt with the very knowledge that they exist being a source of frustration and anguish. In fact he highly recommends that you don't try to complete Chapters 1-4 without getting achievements, pretty much Invoking
That One Achievement. - Bizarro Elements: Every character and magic ability in the game is categorized into one or more elements. Some elements are your standard fare such as "ELEC" or "ICE", but there are more types that fit this trope, such as "MOUSE" and "ORDER".
- Starting in Chapter 2, you can check a recruited Darkner's elemental type at save points, although these are merely cosmetic strings added individually for each enemy. A character with multiple elements will have them listed together, separated by a colon symbol (for example, Rudinn Ranger's element is JEWEL:BLADE). To recap, here are all the elements thus far, along with characters associated with them:
- RUDE: Susie's Rude Buster spell deals Rude-elemental magic. This is the first element to be explicitly stated in the game, from the very first chapter.
- JEWEL: Rudinn and Rudinn Ranger.
- HEART: Hathy and Head Hathy.
- ORDER: Ponman, Ambyu-Lance, Tasque Manager, and Zapper.
- RABBIT: Rabbick.
- DUST: Rabbick and its Underground Monkey counterpart, Ribbick.
- FIGHT: Bloxer and Werewerewire.
- MOUSE: Jigsawry, Maus, and Mauswheel; the latter having the element MOUSE:MOUSE:MOUSE.
- PUZZ: Jigsawry.
- BLADE: Rudinn Ranger and Winglade.
- ICE: Head Hathy and Elnina. Noelle's spells are also Ice-based, such as IceShock.
- ELEC: Werewire, Tasque, Ambyu-Lance, Maus, Werewerewire, and Zapper. The most common element thus far, assigned to over half of all the enemies in Chapter 2.
- VIRUS: Virovirokun and Poppup.
- CAT: Tasque and Tasque Manager.
- COLOR: Swatchling.
- CHAOS: Shadowguy and Pippins. Also, Jevil's element as written in his unused Recruits bio is CHAOS:CHAOS.
- MUSIC: Shadowguy, Wicabel, and Organikk.
- COPY: Shuttah.
- FROG: Ribbick.
- WATER: Elnina, Watercooler, Mizzle, and Miss Mizzle.
- LUCK: Pippins.
- FIRE: Lanino and Guei.
- WIND: Lanino. Berdly is also implied to be able to use Wind magic, based on his tornado attacks.
- SPIRIT: Guei.
- STEEL: Balthizard, Wicabel, and Organikk.
- SMELL: Balthizard.
- MAGIC: Bibliox.
- An actual hidden element system with in-battle effects exists in Chapter 2, but as it stands it is incomplete and only partly relates to recruit descriptions. Elemental armor can defend against bullets of the same element, and in some cases multiple elements. So far, we know of these elements:
- Element 0: Default neutral element, does not partake in element calculations.
- Element 1 (ELEC/HOLY): Only used by Zapper. The unused Sky Mantle item is said to protect against ELEC and HOLY bullets.
- Element 3: Lanino and Elnina in some rain-themed attacks.
- Element 5 (DARK/STAR): Tenna, Lanino and Elnina. The Knight's attacks are mostly of this type, and the Shadow Mantle reduces damage taken from DARK and STAR bullets by 66%, making it a near-requirement to defeat them. The Titan and its Spawn are considered DARK in defense calculations, making the Black Shard deal extra damage to them, but the Shadow Mantle halves damage from their attacks in separate non-elemental calculations.
- Element 6 (PUPPET/CAT): Tasque, Tasque Manager, and Spamton NEO. The Mannequin, Frayed Bowtie, and Dealmaker armours reduce damage from PUPPET and CAT bullets.
- Element 7: The unused Mouse Token item reduces damage from this unused element.
- Spamton’s Q&A also mentions [THUNDER/LIGHT]note and [DEATH/SCYTHE]note pairs, none of which exist in-game yet.
- Starting in Chapter 2, you can check a recruited Darkner's elemental type at save points, although these are merely cosmetic strings added individually for each enemy. A character with multiple elements will have them listed together, separated by a colon symbol (for example, Rudinn Ranger's element is JEWEL:BLADE). To recap, here are all the elements thus far, along with characters associated with them:
- Border-Occupying Decorations: Console releases feature a decorative border around the screen, thanks to the game using a 4:3 display as part of its retraux aesthetic. The border's contents dynamically change based on what area of the game the player is in.
- Boring, but Practical:
- The DD-Burger is a fairly plain healing item but one of the best available in the early game. For just 140 D$, two Darkburgers from Seam's shop can be combined into a single DD-Burger by Malius, healing 60 HP upon use and turning into a Darkburger that heals 70 HP, similarly to the Bisicle from Undertale. Since the party can only hold a limited number of items at once, DD-Burgers allow them to carry a lot more mid-strength heals, with the only disadvantages being that Noelle dislikes them (only healing 20 HP per use) and that they can only be made between Dark World visits.
- The Justice Axe is a weapon that invokes the Magic Feather, but it's still the strongest axe Susie can use with a whopping +12 Attack. Compared to the other superboss-obtained axe, Devilsknife, the only benefits that Jevil's weapon has over the Justice Axe are that it reduces the cost of Rude Buster, and that it increases Magic as well, which influences OKHeal... which Gerson's fight is designed for Susie to spam and thus improve anyway. Since Susie's Rude and Red Busters are influenced by Attack more than Magic, the Justice Axe makes her deal more damage with Rude Buster than the Devilsknife, so ultimately the only benefit it has over the Justice Axe is the cost reduction.
- Boss-Altering Consequence: In Chapter 1, the game lets you choose which machine to build in the "Create a Machine to Thrash Your Own Ass" segment. Rouxls Kaard will use this Thrash Machine against you in Chapter 2, and the head of the machine determines his special attack. The head of the machine also determines the special move that you can use against GIGA Queen.
- Boss Remix: Like Undertale, this is the norm for boss fights rather than the exception.
- "VS Lancer" is a remix of "Lancer" (called "I'm The Bad Guy!" in the Sweet Cap'n Cakes' music shop in Castle Town).
- "VS Susie" includes the motifs from "Susie" and "Imminent Death", and a bit of "Lancer".
- "Chaos King" is a remix of "Card Castle", both of which use motifs from "Basement" and "Lancer". The former also has "The Legend" included in it.
- "Cyber Battle" is a remix of other tracks associated with Sweet Cap'n Cakes ("Almost to the Guys!", etc.)
- "It's Prounounced 'Rules'" is a remix of "Rouxls Kaard".
- "Smart Race" is a remix of "Berdly".
- "Attack of the Killer Queen" combines "Queen" with "Berdly"/"Smart Race".
- "Knock You Down!!" is mainly a remix of "Queen".
- "BIG SHOT" is a remix of "NOW'S YOUR CHANCE TO BE A" (with several other noteworthy Undertale and Deltarune tracks mixed in), while "NOW'S YOUR CHANCE TO BE A" is itself a boss remix of "Spamton".
- In a bit of a twist, "Ruder Buster" is a miniboss remix of the main battle theme, "Rude Buster", played in two separate Chapter 3 fights.
- "It's TV Time!" is Tenna's boss theme and is based on Tenna's theme, heard in a variety of tracks played throughout Chapter 3.
- The Roaring Knight's boss theme, "Black Knife", is a remix of "The Door" and "The Chase", along with taking elements from the song "Nightmare Knight" Toby Fox previously made for the Cucumber Quest fan soundtrack.
- Jackenstein's battle theme, "A DARK ZONE", is a remix not of anything from Deltarune, but of "Spooktune" from Undertale.
- "Hammer of Justice" is a remix of "Gyaa Ha ha!", Gerson's character theme, and both tracks call back to Undyne's various tracks from Undertale.
- The Titan's boss theme, "GUARDIAN", is a remix of "Dark Sanctuary".
- The theme for the Titan's spawn, appropriatly titled "SPAWN", also takes elements from "Dark Santuary".
- Boss Warning Siren: "Gallery", a short, but tense theme, plays during the cutscenes immediately preceding the fights with King and Queen.
- Bowdlerize:
- In-universe. During Chapter 3 when doing the rhythm minigame as part of Board 2, Ralsei doesn't like the lyrics to the song they are playing, Raise Up Your Bat, so he changes them while singing it. You can see the original lyrics in white, but when the blue highlights reach lines he doesn't like, they are changed to something softer and goofier.Original lyrics: When the demon heart is crying and the blood is gushing bright, raise up your bat for the burning fight.Ralsei's version: When the happy heart is smiling and sun is shining bright, raise up your hat for a funny sight.
- On launch, Chapter 4 contained a line where Susie calls Catty a "furry degenerate" in response to her drinking Alphys' milk saucer before her. This was quickly changed to "furry freak" in a patch.
- In-universe. During Chapter 3 when doing the rhythm minigame as part of Board 2, Ralsei doesn't like the lyrics to the song they are playing, Raise Up Your Bat, so he changes them while singing it. You can see the original lyrics in white, but when the blue highlights reach lines he doesn't like, they are changed to something softer and goofier.
- Breaking Old Trends:
- Unlike Jevil and Spamton NEO in Chapters 1 and 2, the hidden boss in Chapter 3 is fought regardless of if you completed their appropriate side quest or not. The side quest instead revolves around obtaining a piece of equipment after defeating another secret boss, which is needed to allow you to survive longer than two turns against the actual superboss, which is still extremely challenging regardless. Even then, the side quest itself isn't even necessary to pursue, as it's fully possible to defeat the superboss without even touching it, albeit much more difficult.
- The hidden boss of Chapter 4 breaks the trend of the hidden bosses being enemies, with the boss being the friendly Gerson in a one-on-one sparring match with Susie. The title of his boss theme also isn't in all caps.
- Unlike Jevil and Spamton NEO, both of which can be defeated peacefully or violently, the Roaring Knight must be defeated through FIGHTing, with no option to spare them or tire them out. Because of this, they only provide a weapon after defeating them in addition to their Shadow Crystal, whereas Jevil and Spamton would provide a weapon or armor piece depending on how they were defeated. There are multiple ways to go about the Hammer of Justice fight, but you're expected to attack in order to build TP and then use a magic spell in order to impress him; however, your attacks will never connect (he, too, only provides a weapon with the Shadow Crystal upon victory).
- Break Meter: All spareable enemies from Chapter 2 onwards have a MERCY bar, which is filled using ACTs and allows them to be spared if full.
- Breather Episode: Ironically, the Chapter 4 hidden boss is this compared to the chapter itself which is full of heavy moments. Rather than battling someone insane or an Eldritch Abomination, the battle is a duel between Susie and Gerson, a kindly old man who wants to test Susie's resolve. The battle itself is also on the lower end of difficulty for a bonus boss, particularly compared to the Roaring Knight in Chapter 3.
- Brick Joke:
- Among the various Easter eggs in Undertale that hinted at Gaster and Deltarune is a Sound Test of sorts where the player is thanked for the "feedback" of listening to Gaster's song for a few seconds. Years later, the Deltarune demo is presented as another survey and Gaster's Theme is not-so-subtly featured in both the morbidly humorous vessel setup as well as in various other places later on.
- The name for the Hotel track in Undertale was "Can You Really Call This A Hotel, I Didn't Receive A Mint On My Pillow Or Anything". Cue Queen's Mansion, where returning to the private rooms after escaping will have a Swatchling tell Kris that they put a mint under their electric cage, but Kris shouldn't mistake the mansion for a hotel for it.
- Early in Undertale, Sans teases the protagonist with a fake wordsearch puzzle featuring a character named "Ice-E" on the side of the paper. Ice-E is never seen or mentioned again anywhere in Undertale, but turns out to be the mascot of a pizzeria in Deltarune's Hometown. And in Chapter 2, the nonsense word in the word search that almost matched the first row of the word search is revealed to be just one letter off from Ice-E's "Catchphrase".
- One where the setup can't actually be seen in the final release of the game. The game files contain unused images for pages of Ralsei's Manual
, one of which mentions the W button, which does nothing except for adding "pulsar cannons" if you do cooking. In Chapter 3, during the cooking minigame, holding down W when the minigame starts will indeed summon pulsar cannon beams
on the popularity screen. - In Chapter 2, when Susie eats a whole cake when interacting with the cauldron in Ralsei's castle, she notes that it's a little thick on the frosting. Come Chapter 4's optional tea party, a new cake is present, notably having less frosting than the day before, likely being Ralsei's attempt to improve on it for her.
- The theme that played during Sans' date at MTT Resort in Undertale was "It's Raining Somewhere Else". At the end of Chapter 4, during the nighttime walk home through the rain to Kris's house, the theme playing is called "The Place Where It Rained", and true to form, it's an expanded version of the above theme, with Sans' leitmotif replaced with a new melody.
- Bullet Hell: In addition to the combat system being a refined form of Undertale's, there are also elements of it incorporated in the overworld at certain parts.
- Bus Crash: As part of the Alternate Universe setting in Hometown, headstones for some of the monsters who were previously part of the Amalgamates, as well as the shopkeeper Gerson, can be found in a small graveyard, retroactively naming them as well.
- But Thou Must!: Appears to be the theme of the game; despite appearing to have a similar structure to Undertale in terms of choosing between pacifism or violence, the game constantly forces you along only a single path. You are even told multiple times that "your choices don't matter", and many of the choices you are offered get rescinded immediately, in direct contrast to the extremely choice-driven experience of Undertale. The biggest choice a player can make is with the Weird Route, but it involves going completely Off the Rails and its results are less than pleasant.
- But You Were There, and You, and You: An inanimate variant. Every character you meet in the Dark World has an inanimate object equivalent in the Light World.
- The Cameo: The Amalgamates never came to be, but Everyman is still out there, appearing as a Recurring Extra as pieces of graffiti or rarely as part of boss attacks.
- Cassandra Truth: Attempting to talk to Undyne about the Dark World causes her to laugh you off. She discovers the truth the hard way in Chapter 3, entering the Dreemur Residence's Dark World just in time for the Roaring Knight to kidnap her.
- Central Theme:
- In opposition to Undertale: Your choices don't matter. In Chapter 1 alone, your Character Customization choices at the start of the game are immediately discarded, you're unable to choose your partner in class, Dialogue Tree choices will result in no actual difference (sometimes, you won't even be given time to pick a choice before another character cuts you off), characters will tell you multiple times your choices don't matter, you are incapable of engaging in fully violent or pacifistic playthroughs like you could in Undertale, and at the end of the game, control of Kris is literally ripped away from you. If you corrupt Noelle in the Weird Route, however, this theme is broken in the most horrifying manner possible. This eventually progresses towards the idea of predestination where the future is set in stone and there's only one possible outcome, with one of the last verses of the prophecy emphasizing that there's "only one way to save the world".
- Another central theme that's directly tied to the first is seemingly "freedom", whether it be release from a prison or the ability to have agency at all, and whether the price or consequences for obtaining it is worth it. The Shadow Crystal holders mention "freedom" a lot. At the end of Chapter 2's Weird Route, it's implied Noelle becomes more aware of the lack of control over her own life and how she was being manipulated by "Kris". And after the battle against Spamton NEO in the Normal Route, Kris is deeply unnerved at the potential cost of what it takes to gain "true freedom". Gerson takes this in the other direction, asking Susie how she'd like the unwritten ending of the story to go, and is pleasantly surprised when Susie replies she doesn't want there to even be an ending; she wants the story to last forever, and thus in his words, she "chose eternity".
- Paired together, the two themes link into an overarching conflict of free will vs. fate. One half of the cast believe that it's possible to seize freedom and make your own path in life, while the other half believes that who you are and who you become is fundamentally set in stone and "no one can choose who they are" because it was already chosen for them. Kris's main conflict is being pulled between two people standing on the two different sides: Susie, who they genuinely like as a free spirit making her own choices and someone determined to avert the grim ending of the prophecy, and the Roaring Knight, who's dead set on making sure the events of the prophecy remain unaltered and has some sort of leverage over Kris to force their compliance. From a meta perspective, it serves as a contrast between linear games with only one ending verses games with open-ended multiple endings, and whether a story is just a linear series of events or something to rewrite as one sees fit.
- The fear of losing control, in particularly of the control one has over their own identity. Just about every character in the story has a lost an essential part of who they are, or had part of their identity stripped from them at some point. Susie's stereotyping as the "bad girl" turned her into a jaded delinquent, when in reality she's a deeply kind and warm person who lacked a chance to show these traits. Ralsei, like all Darkners, is defined by his relationship with the Lightners, and is terrified of losing his purpose as he slowly grows outside the bounds of servitude. There are even more minor examples, like Asgore losing his role as a father and despairing over it, or Berdly trying to keep up his reputation as The Smart One and causing trouble as a result. Chief of all here is Kris, whose life has been effectively taken over by a foreign entity they have little control over, and with whom they have an adversarial relationship. And there are increasing hints that even the player isn't immune to this, with increasing implication that the game itself is trying to control the player in the same way they control Kris by removing their agency and freedom of choice.
- Knowledge that mentally damages its knower or otherwise leaves them worse for wear is a recurring theme throughout, usually with the secret paths in each of the chapters. Jevil came to learn something disturbing about the world, driving him to madness, starting the King's ironclad rule, and causing Seam's cynicism. Spamton was highly successful thanks to his benefactor, but his entire business empire crumbled overnight when he tried to share his secret with Tenna. The Legend of Mantle is one big hint towards the existence of the Weird Route, giving you, the player, the knowledge needed to abuse Noelle. Chapter 4 orbits around a prophecy with an uncertain, but tragic end; Ralsei knows said end and tries to protect the party from learning this uncomfortable truth.
- Opposite the above, for the player, it's not having all the information. It's clear that something is going on that the player should be aware of, but every time the player gets close to a kernel of truth of what's really happening towards the endgame something prevents the truth from coming out, whether it be an interruption from someone else, someone wording things in vague, uninformative ways (or just refusing to say anything about the matter at all), or physical evidence being destroyed or otherwise removed from access. As the chapters progress, the game looks more and more like it's intentionally trying to withhold information from the player and playing off their lack of knowledge to guide them in a specific direction. Any attempt to learn about the Knight's identity through Kris is immediately stonewalled through them deleting their phone contacts, refusing to imagine the Knight's true appearance when commanded to, not going into likely hiding spots in the Light World, and resisting our attempts to learn the Shelter codes. The terrible penultimate verse of the prophecy is shattered before the player gets a chance to see it, the picture of the "angel" is obscured to players with descriptions too vague to tell us anything, and Ralsei, who knows a lot about what's really going on, is intentionally withholding information to avoid burdening the others, which prevents us from learning anything important either. This includes information about some of the other major characters of the story as well. While Noelle has an older sister named Dess, nothing about where she is or what happened to her is explained, even by Noelle herself, and the incident that got Asgore discharged from his position as police captain isn't described in detail and is just referred as vague You Know What You Did statements and otherwise treated as a taboo subject to discuss.
- Cerebus Syndrome: Each chapter tends to take a turn for the dramatic once the final area has been revealed, though with comedy still interspersed throughout.
- Chapter 1 (Card Castle) has Lancer realize that Susie and his dad King will have to fight, and thus commands the Lightners locked up to prevent either of them from getting hurt. Most of the comedy comes from Rouxls Kaard and Susie's recent Heel–Face Turn making her not so good at ACTing yet, but the humor screeches to a halt once more when the party reaches King.
- Chapter 2 (Queen's Mansion) has Queen catch the party alongside Noelle and Berdly, thus declaring her truce with Kris over and proceeding to capture the Lightners. The shenanigans inside remain very silly, but the topic of getting Noelle to safety is treated rather seriously, and things take a far turn for the worse once Queen plugs Berdly. Exascerbated with the Weird Route, which skews all of Kris and Noelle's interactions into a much more creepy context and culminates in Noelle using the fatal SnowGrave spell on Berdly, putting him in a coma. Queen's Mansion is mostly skipped, and what's left is taken over by Spamton, who replaces her as the final boss entirely.
- Chapter 3 has the Lightners leave the Green Room entirely, which drives Tenna mad as he demands the Darkners hunt them down. When they eventually are about to leave the TV World, he's driven to fight the Lightners directly. He eventually relents after they promise to find somebody to take him in... only for the Knight to show up, effortlessly dispose of Tenna, almost kidnap Toriel, and then kidnap Undyne instead, taking her with it into the shelter to Susie's dismay. It's this moment where the game faces a tonal shift, with Susie taking the Dark World business far more seriously and the party's efforts being focused into stopping the Knight and figuring out how to enter the shelter.
- Chapter 4 takes a turn when Susie makes the 2nd Sanctuary, having a run-in with a Fake Gerson and Ralsei revealing why he's been so secretive. The 3rd Sanctuary gets even worse as Ralsei indirectly reveals that the prophecy doesn't end well, though we don't actually see what the ending is and Susie brushes it off, declaring that the gang will Screw Destiny no matter what. The Knight later resorts to making even more Dark Fountains to stop the Delta Warriors, creating a Titan that severely overpowers the heroes until Gerson saves them. Susie remains despondent by the end even after successfully defeating the Titan, as they couldn't make any progress in getting into the shelter.
- Challenge Run: In the Playstation version of the 2025 release, Toby Fox was forced to implement trophies for the game (as in Undertale) despite his dislike for achievement systems. Unlike Undertale, however, there is an in-game acknowledgement of these trophies; specifically, an acknowledgement from the VOICE for not getting any when playing through all four Chapters. While some trophies are quite simple (if difficult) to avoid, like not dying or getting hit less than a certain number of times, there are numerous trophies that can pop by a plethora of hidden "traps" within the Chapters (examples below). Keep in mind that this can only be attempted once per account — the trigger only occurs if zero trophies have been popped, rather than just if the requirements have been missed. Fortunately for those that attempt this, trophies will only unlock once you leave the room it was obtained in, giving you time to exit the game before it pops.
Though this may make you fear entering the next room at all during this challenge...INTERESTING. YOU FAILED TO ACHIEVE ANY MARKS. WHAT ARE YOU? "[creator name]". I VERY MUCH LOOK FORWARD TO THE NEXT.- You cannot perform the Weird Route, as both of the rings you have to give Noelle to progress the route in Chapter 2 count towards the "RING" achievement. Likewise, you cannot perform the Sword Route in Chapter 3 as the sword in the Game Within a Game also counts as equipment for the "SWORD" trophy and the pixellated Kris avatar leaving the screen unlocks "MIRROR".
- As mentioned previously, hardly any damage and zero Game Overs are allowed. Unfortunately, the presence of the "CONSUMER", "ARMOR", and "SWORD" trophies will extend battles even further, since they respectively allow no items to be used (INCLUDING MOSS!), no armor to be worn, and no weapons to be switched.
- "TREASUREHUNTER" forbids you from collecting more than 110 "treasure". While treasure chests are mostly useless to you anyway given you can't use their contents, this also applies to the golden dots collected in the Jackenstein battle. On the topic of Jackenstein, his Claimb Claws have a trophy earned by spending 90 seconds on any climbing surface.
- "CUTLERY" and "SYMPHONY" are avoided through achieving Z-Ranks, which may be difficult to get without taking damage.
- "RING" and "THRONE" both have multiple triggers you would probably forget about; the former includes ringing bells and listening to the phone ring in Spamton's shop, and the latter pops when inspecting Chairiel, toilets, and King's throne. "CLOSENESS" is also like this, but with far more triggers, mostly related to optional positive interactions like hugging or comforting Ralsei.
- Finally, "MIRROR" and "ERASE" forbid the copying or deleting of SAVE files, meaning you'll need to completely delete your save data from the system itself to get rid of a tainted SAVE. And like many previous trophies, they will also pop after a few minor, unsuspecting checks.
- Character Level: The characters have different LV in the Light World and Dark World, and each seems to mean something completely different.
- In the Light World, LV and EXP are implied to be the same as in Undertale, quantifying Killing Intent. However, this is completely cosmetic, as there is no combat in the Light World and Kris stays fixed at LV 1 and 0 EXP, reflecting the SOUL's inability to make them kill anyone.
- LV in the Dark World seems to be a more typical measure of the character's strength, even being called "False LV" in the game files. Increasing it raises HP, Attack, and Magic (excepting Kris for the latter), but not Defence. However, EXP is non-existent: Battles in Chapter 1 specify you got 0 EXP after every each battle to emphasize the violence as nonlethal, after which it's not shown at all, not even when you finally do destroy some (non-sentient) enemies in Chapter 4. Even on Chapter 2's Weird Route, which does involve a party member killing enemies to get stronger, the system isn't framed in the exact same way that it was in Undertale. Your LV is only increased by story progression, starting each chapter equal to its number and going up one when you've sealed all Dark Fountain(s). That being said, there is a sort of temporary Stat Grinding mechanic, where violent encounter outcomes gradually raise your stats, giving the message "You became stronger". However, this boost is reset each chapter and maxes out at less than you get from one LV.
- Cheated Angle: Because most of the characters aren't drawn from top-bottom perspective, Kris's laying down in bed sprite is the same one as their left facing sprite and they simply walk out of bed without changing their angle.
- Chekhov's Gunman: This time, you don't need to dig into the game's code or mess with the save files to catch hints of Dr. W. D. Gaster's presence in the world. To begin with, an entity who's implied to be Gaster or someone related to him heralds the release of Chapter 1 and its opening act when the game is first loaded. The noise from Entry #17 plays when trying to make calls in the Dark World, he's implied to have driven the Shadow Crystal holders insane with his revelations, and his theme song is incorporated in several tracks of the soundtrack. The shelter door makes a murmuring noise that's actually a slowed-down version of the noise from Entry #17. But by far the smoking gun for Gaster's likely involvement in the story is the presence of the site "deltarune.com" since December 2015 (when Undertale was still a very recent release), and until the actual game was announced, there was only one file on the website: a darkened image of lines of WingDings text (Gaster's signature writing style).
- Chess Motifs: King is completely stationary, hiding within Card Castle and having Lancer do most of the dirty work, and his defeat renders his threat completely null and void, much like the king piece. Queen is the opposite, constantly appearing around Cyber City and acting in bombastic ways, much like the queen piece. However, this analogy doesn't carry over to the rest of the game, as the Knight doesn't seem to act like the piece and Tenna has absolutely no connection to chess.
- Choice-and-Consequence System: Though the overarching plot remains the same, being violent has consequences for certain characters: Attacking Queen leads to Berdly frying his arm, losing recruits in Chapters 3 and 4 leads to Tenna and Jackenstein's deaths. The Weird Route drastically alters several scenes, but also has subtler differences like Ralsei disapproving of Kris taking Noelle to the festival.
- Chromatic Arrangement: Kris, Susie, and Ralsei form this in the Dark World, with Kris being blue, Susie being reddish-pink, and Ralsei being green.
- Close-Contact Danger Benefit: You earn Tension Points, which can be used for spells or certain ACTs, when the SOUL comes close to bullets without actually touching them.
- Close on Title: Each chapter ends with the game's title showing up.
- Color-Coded for Your Convenience:
- The flying numbers that Shows Damage are colored differently based on which character dealt said damage: blue for Kris, pink for Susie, green for Ralsei, yellow for Noelle, dark green for Gerson and red for the Knight.
- As of Chapter 2, hostile Darkners glow red in the overworld to distinguish them from harmless NPCs, though some NPCs become hostile if you fulfill certain conditions (such as breaking a vase near a Swatchling).
- The Recruits menu uses a different colored background for the chapter of origin of each enemy: purple for Chapter 1 Darkners, cyan for Chapter 2, green for Chapter 3, and blue for Chapter 4.
- The Colored Cross: In the demo, the nurse in the hospital wears a white cap with a red cross on it, but it was changed to a cyan cross
in the paid release. - Color Motif: The specific pairing of pink and yellow appears in a lot of imagery across the game, with no obvious meaning yet outside of usually being tied to optional and frequently ominous content. Spamton's glasses have pink and yellow lenses, the mysterious "FRIEND" face has pink and yellow eyes, the Odd Controller that Kris receives for Chapter 3's Sword Route is shown to have pink and yellow buttons if examined, and Chapter 5 of Lord of the Hammer (implicitly alluding to Deltarune's own Chapter 5) is titled "The Field of Pink and Gold". Chapter 5 is also suggested to focus on Asgore, whose color scheme is predominantly pink and gold between his hair and shirt. Less seriously, it also appears as the color of "Cat" Mike's eyes as a nod to wild fan theories.
- Combat Exclusive Healing: Ralsei, Susie, and Noelle's healing spells are only usable in combat, and the TP they use doesn't even stay after battle, as it's converted to money. That said, you can use healing items or save points to restore health in the overworld.
- Combination Attack: Some ACTs have an upgraded version that's used with one or both other party members, but using them also uses up said party members' turns. Played straight with Susie's Red Buster, which deals massive damage.
- Cosmic Horror Story: Both in a meta sense and in-universe.
- Meta-wise, the actions of the player are seen as incongruous with Kris's personality, as if you are a higher being who uses them as a vessel. This extends to the hidden bosses in Chapters 1 and 2, who have gone mad from hyper-awareness of their world, and Chapter 2's Weird Route, where the player, through Kris, compels Noelle into murdering Darkners and putting her own classmate in a coma. In Chapter 4, the prophecy explicitly says that Kris is a "cage, with human SOUL and parts".
- In-universe, the Dark World is a sub-dimension consisting of inanimate objects given life through the power of the Dark Fountains. If too many Dark Fountains are formed, creatures called Titans will form from them and destroy both Light and Dark.
- Creator's Culture Carryover: Although the game is set in a fictional world of monsters, Susie refers to her school's water fountain as a "bubbler", a fairly-obscure term used only in small regions of Wisconsin and New England in America. The game's creator, Toby Fox, is from New Hampshire.
- Creepy Basement: Card Castle and Queen's Mansion both have one, being dimly lit areas with unsettling music playing in the background. Both of them hold their respective chapter's hardest fights (albeit only on the Normal Route in Chapter 2, with the Weird Route moving the fight to the Dark Fountain).
- Creepy Cathedral: Chapter 4's Dark World is the Dark Sanctuary, the Dark Fountains created within turning a small and welcoming local chapel into a gigantic gothic cathedral.
- Critical Existence Failure: Downplayed by the game's HP and revival mechanic. When a party member's HP is depleted, their Non-Lethal K.O. state is represented by their HP being set to -50% of their max HP, which can be healed to the positives to revive them. The implication is that one can fight unhindered to the point of collapsing, but not dying.
- Crystal Dragon Jesus: "The Angel" is worshiped at a church, complete with stained glass, a priest, and Sunday school. Despite this, the metaphysics of the world itself has more in common with Shinto than Abrahamic religions, and the philosophy of the church Darkners (that is presumably at least somewhat similar to the theology and metaphysics of the Deltarune world) resembles Taoism far more. This would normally be an innocuous religion were it not for "the Angel's Heaven" being the thing that the Delta Warriors are supposed to banish, according to the prophecy spoken by Ralsei, which has unsettling implications. Strangely enough, the actual religious practices shown in the story as of Chapter 4 focus entirely on the Legend of Delta Rune (aka, the prophecy) and the Three Heroes rather than the Angel itself, which goes completely unmentioned during the ceremony's opening choir and the sermons.
- Cutscene Power to the Max:
- In cutscenes, Ralsei's healing magic is frequently used, always heals to max health, and can affect multiple characters at once (with some of these also applying to Susie's healing once she learns it). Meanwhile, the game mechanics prevent healing magic from being used outside of battle at all, and it's also fairly costly, needs a lot of investment to consistently full-heal, and in most battles only affects one party member at a time.
- Depite the memes, it's actually Susie who benefits from this in the confrontation with the Knight at the end of Chapter 4. She charges three Rude Busters in a row to try and hit it, even though the attack normally takes 50 TP to be used. Chaining three Rude Busters isn't exactly easy, and she goes right back to normal after the cutscene.
- Dark Is Evil: Dark Worlds and Darkners as a whole aren't evil, but an excess of darkness will bring about the Roaring. The Knight, an enigmatic figure who's threatening to bring the Roaring by creating Dark Fountains, is also implied to be powerful, deceitful, and a corruptive influence that may or may not be responsible for Jevil and Spamton gaining their Medium Awareness.
- Dark Is Not Evil: Although some Darkners are bad people, most of them are just normal folks living their life in the Dark World.
- Darker and Edgier: While Undertale could get quite dark, Deltarune is much more direct and, to a lesser degree, somewhat more cynical. Characters are less hopeful and more jaded, and the heavier themes come into play much earlier. There is also a fair amount more profanity (which is likely why the game went from an E rating to a T rating after Chapter 1's initial release), particularly in Chapter 2.
- The endings of Chapter 3 and Chapter 4, in particular. Between the appearance of the Knight, Undyne's disappearance, the raising of the stakes, and the literal darkness that Kris navigates throughout Chapter 4's Dark World, the player is made to feel how much darker this game is.
- Dark Reprise: Lancer's theme
is very upbeat and goofy, and showcases his status as a Minion with an F in Evil. The main leitmotif gets a much more sinister remix when fighting his father.
- Deconstruction:
- Following in the footsteps of its predecessor, Deltarune loosely tries to deconstruct RPGs and the storyline and cast members of classic Dragon Quest or Final Fantasy-style games by having more of a psychological approach and a nitpick of the various tropes without trying to be too self-aware or critical. However, while Undertale was a deconstruction of Level Grinding and RPG combat, Deltarune mainly deconstructs the idea of But Thou Must! that most RPGs use by default thanks to usually having one defined plot outlined for the story, by showing just how bleak and suffocating a world where choices are superfluous at best would truly be. It outright proclaims that your choices are irrelevant and simply not giving you much in the way of options to begin with.
- The Weird Route of Chapter 2 deconstructs the player's control over party members in an RPG, as the player has the power to mold Noelle into a killer through commanding her in battle and tailoring Kris's out-of-battle responses to gaslight her towards violence. It's also implied that Kris is aware of, and horrified by, what you, the player, are making them do to her, but is unable to do anything about it.
- The nature of Superbosses (and more specifically the steps needed to reach them) are deconstructed in Chapters 2 and 3. They’re convoluted, only reachable via Violation of Common Sense (namely continuing to interact with Spamton in Chapter 2 and playing a game Kris is clearly uncomfortable with in Chapter 3) and made abundantly clear that Kris wants absolutely nothing to do with them, to the point of outright screaming if they answer they’re not okay after the Spamton NEO fight. Chapter 3 also questions the idea of the optional content leading to a potential Golden Ending. When you face the boss of the Sword Route, they mock you for wondering if obtaining the Shadow Crystals will really get you what you want when you have no idea what they even do yet, and accuse you of partly only going after it for the challenge.
- Elements in Chapter 3 and 4 also deconstruct The Player Is the Most Important Resource. It's strongly implied that Kris is in league with the Roaring Knight and is actively sabotaging the group's attempts to win against the prophecy. And while they're aware of the presence of the SOUL guiding them, they're openly hostile to the SOUL and make active attempts to defy it, no matter how nobly or horribly you make them act. The harder the SOUL attempts to take steps to put the story in a more favorable direction, the more violent Kris gets in resisting it, such as resorting to self-harm or attacking the SOUL. If you manage to "win" the battle against the Roaring Knight without taking a hit, Kris will outright throw a hint to the Roaring Knight to stop trying to win through attrition and defeat them another way, and refuse to move if you catch up to them in the Dark Sanctuary. It's later implied the only reason they harbor the SOUL to begin with is to enter the Dark World, and otherwise serve as a living "cage" to confine them. So the player character may be important to the plot, but that doesn't mean they'll be important in the player's favor.
- Defend Command: DEFEND is a new option in the battle interface that lets party members steel themselves to take less damage on the enemy's turn. This also boosts the Tension Point gauge, which applies instantly with obvious benefits (for example, if you lack enough TP to heal with Ralsei's magic, defending with another character can let him cast the spell on the same turn).
- Deliberate Game Crash: When the player is given the choice to name your and the vessel they created in the intro sequence, naming either after "GASTER" will forcibly reset the chapter as soon as the R is inputted. The same happens if you start a new game in another chapter when prompted for a name.
- Deliberately Monochrome: The Lightner characters have black-and-white dialogue portraits. The Darkner characters have fully-coloured portraits.
- Demoted to Extra:
- Within the four chapters that have been released so far, most of the returning characters from Undertale play a much smaller role, with the player being free to completely ignore the vast majority of them. Some characters don't even show up at all: Asriel is away at college, while Gerson Boom and the Amalgamates (or at least their constituent monsters) died before the events of the game. However, in Chapter 4, Gerson is reincarnated as a Darkner and is a major character for that chapter. Undyne, Toriel, and Asgore are also hinted to play a much larger role in future chapters.
- Lancer tags along for Chapters 2 and 3 but his role in them isn't as big as in Chapter 1.
- Deranged Animation:
- Burgerpants (named Pizzapants here) is back with a Downplayed example, making use of portraits instead of an entire shopkeeper menu. Nevertheless, almost every line of dialogue with him will change the shape of his head or the size of his face, with the art style wildly varying between each expression.
- Berdly has a comically distorted portrait during his more smug moments. There's also his entrances into cutscenes, such as him slowly floating and circling down the side of the screen when he and Susie rescue Noelle.
- Spamton is constantly glitching and twitching, enlarging his head to launch miniature copies of himself, spew stock sales lexicon, or suck in the battle box, and he'll horizontally stretch the first few times you try to deny his final offer. At his shop, he looks in all sorts of directions and tensely shakes during some of his lines, with his sprite scrambling at a couple points (including when he tries to tell Kris about the Knight). He gets worse as Spamton NEO, moving like a deranged marionette as his limbs flail and circle during his attack animations.
- Developer's Foresight: As with Undertale, Toby Fox and crew have put so much effort into having the game respond to almost anything a player might do that it required a subpage to contain the examples.
- Double-Meaning Title: Aside from being an anagram of Undertale, Delta also is used in mathematical notation to designate the difference between two values, and Deltarune has many changes from Undertale. Finally, the Greek letter Delta is a triangle, at least when uppercase, and the party in Chapter 1 consists of three heroes known as the Delta Warriors, the Delta Rune itself being the name of the Dreemur family's royal crest.
- Dramatic Irony: Much of Deltarune's lore, humor, and character interactions are dependent upon the player's foreknowledge of Undertale, and the game expects you to make choices based on that foreknowledge. For example, the player knows that Undyne and Alphys should be in a relationship, and that the lonely ghost is a person worth talking to, and that bake sales are a common occurrence.
- In Chapter 4, after reading the penultimate verse of the prophecy, Susie doesn't like what it means and states none of them would let it happen. She's blissfully unaware that Kris is most likely in league with the Roaring Knight, which means they not only would let it happen, but they're also actively trying to make it happen.
- Driving Question:
- What happened to December Holiday? By far the biggest overarching mystery of the game, with the game often alluding to it throughout multiple chapters both directly and indirectly. Multiple characters are actively searching for her, and there are hints of her fate scattered throughout the game both in the world and, potentially, in the code itself.
- Why is the Knight trying to bring the Roaring? It's clear after Chapter 2 that opening too many Dark Fountains at once is a very bad thing, and yet the Knight seems dead-set on causing this apocalyptic event to happen. Whatever the reason, they certainly aren't telling us, or telling us anything for that matter, doing everything with stone cold silence.
- What happens at the end of the Prophecy? Chapter 4 reveals the full scope of the prophecy of Delta Rune, but when we reach the penultimate verse of the prophecy it's always shattered before we know what it says, and Ralsei is outright desperate to keep anyone from seeing it. The only hint we get is that it's a "tragedy" and the "only way to save the world", but the actual piece of info stating what needs to be done is broken by Susie in a rage before the player gets a chance to even see it, and only says they won't let that happen. But it's clearly so bad it leaves her severely shaken even as she tries to put on a brave face.
- How are Kris and the SOUL connected? At first, the player is lead to believe that Kris is merely the Player Character. However, at the end of Chapter 1, Kris rips their SOUL out and throws it in the cage in their room, with its dented appearance hinting that this isn't the first time either. This tells the player that Kris and the SOUL are two separate beings with Kris acting as a puppet for the SOUL, which gets confirmed in Chapter 4 with the prophecy mentioning a cage with human parts, obviously referring to Kris and the SOUL. Not only that, but Kris also has their own thoughts and feelings separate from the SOUL, and they do not appreciate being under someone else's control. With that in mind, they seem to need the SOUL for something that would likely be impossible for them on their own. What that is has yet to be seen.
- What are the Shadow Crystals? Whatever they are, according to Seam, they cast a shadow despite being invisible. The first time you use one, it shows you what the Dark World looks like in the Light World (the school rec room, the library computer lab, Kris' living room, etc.), yet the game dismisses it as a part of your imagination. Every other use afterwards does nothing. In the Light World, they appear as pieces of glass separate from the Ball of Junk that give you a bad feeling whenever you try to get rid of them. The only other use they have is giving them to Seam, who always seems to know who has them and how many there are. On top of that, two of the Shadow Crystal holders, Jevil and Spamton NEO, are ranked as the most powerful enemies in the game who inevitably had their minds broken after using them. At first, this could be a case of With Great Power Comes Great Insanity, but Gerson is also ranked at their level despite not using his Shadow Crystal. Adding to their mystery is when Susie broke off a piece of the Roaring Knight's sword, the piece manifesting as a Shadow Crystal and a Black Shard. This could hint that the Roaring Knight is connected to them in some way.
- Dug Too Deep: The Weird Route of Chapter 2 is framed this way. The only reason it happens at all is because the player went digging for secrets and alternate outcomes, mirroring Undertale's similar commentary about the player's inclination to do heinous things within the game world just to see what would happen. Rather than straightforwardly delivering the consequences of the player's actions, the Weird Route is presented as the player's attempt to learn Things Man Was Not Meant to Know and "breaking" the game as a result. Spamton, the master of Psychological Projection that he is, implies his fall from glory happened from something similar.Spamton NEO: THERE WILL BE NO MORE [Miracles], NO MORE [Magic]. YOU LOST IT WHEN YOU TRIED TO SEE TOO FAR... YOU LOST IT...
- Dump Stat:
- Zigzagged with the Attack stat. Violence being nonlethal lowers the penalties for dispatching random encounters by force, but also the rewards (mostly-cosmetic recruits vs some stat boosts that only last the rest of the chapter). A near-Pacifist Run is essentially the default, so most of the time you can comfortably prioritize other stats or equipment bonuses. However, the game progressively introduces situations where attacking truly causes no tangible loss (King, Rouxls Kaard, Tenna, Titan Spawn), provides one of Mutually Exclusive Power-Ups alongside ACT-based completion (Jevil, Spamton), contributes to an ultimate nonviolent victory (damaging Queen's acid shield, trying to attack the Hammer of Justice instead of just defending), or is outright the only means of resolution (GIGA Queen, Spamton NEO in the Weird Route, Roaring Knight, Titan). By the games' self-proclaimed midpoint, most players will take the hint to at least hold Attack-boosting equipment in reserve.
- Increasing Susie's Magic stat is initially a distant priority to Attack, since her only functional spell is affected more than twice as much by the latter stat. But her healing spell's power is proportional to Magic, and it gradually goes from a joke to a Heal Prayer alternate that sacrifices TP efficiency for turn efficiency.
- Kris's ACT abilities do not count as magical, so increasing their Magic stat is useless. This also makes them the best candidate for wearing Magic-debuffing equipment like the TennaTie.
- Early-Bird Cameo: Pippins appear near the end of Chapter 1, in the mob overthrowing King. In Chapter 3, Pippins become a recurring enemy and NPC.
- Early-Installment Weirdness: Primarily in Chapter 1:
- Recruiting and losing enemies doesn't exist. The only effect defeating enemies has is that the events after King's defeat will play out differently if they were merciful or violent, and subsequently Kris and Susie will be rushed out of Card Kingdom if they were violent. In Chapter 2, every Chapter 1 Darkner is recruited immediately. This is justified, as not only is Card Kingdom extremely close to Castle Town, Kris grabs everything in the room that was Card Kingdom, which means that any darkner that would have been lost would still be recruited anyway, given they never left the room.
- The Shadow Crystal boss, Jevil, is completely out of the way and doesn't appear outside of his associated side quest and fight, whereas Spamton has a miniboss fight that can't be skipped and is alluded to by Swatch, Gerson serves as a recurring ally throughout his chapter and the Knight is the Knight of Cerebus Big Bad who is always fought immediately after Tenna with Seam mentioning the Shadow Mantle in Chapter 2's epilogue. At the time of Chapter 1's release, he wasn't even known as a Shadow Crystal holder, as he never handed out one upon defeat, only doing so in future versions of the game once Chapter 2 came out. He does get a mention in Chapter 4 that retroactively makes him Chapter 1's Greater-Scope Villain, however.
- Entering the Field displays the name of the area's theme, "Field of Hopes and Dreams", toward the top right corner, a concept that appears absolutely nowhere else in the game thus far.
- Older versions had the Wrist Protector, an item obtained by reaching the Dark World in under 8 minutes that allows quickly skipping through text boxes automatically. It was removed and its function was given to the player inherently.
- Easy Levels, Hard Bosses: Deltarune shares the same difficulty traits as Undertale: most areas are straightforward to navigate and it won't take longer than 2-3 turns to fight or spare a group of enemies, but bosses have a variety of dangerous attacks and take at least twice as long to repel no matter which method you use, with major fights breaching 15-20 turns in length. The number of bosses has also been upped from Undertale, with Chapter 2's Normal Route alone containing seven required bossesnote , a superbossnote , and three Unique Enemy encounters framed like mid-bossesnote .
- Eldritch Location: The Dark Worlds: a mysterious entity can suddenly decide to give life to a room which becomes a micro-world, where all the items become characters with a story, and where the furniture becomes complex structures. It even applies to electronic devices whose software becomes a part of this world.
- Emergency Energy Tank: Revive Mints fully restore the HP of a party member if they're knocked down, but only two or three can be found in each of the first three chapters. Averted in Chapter 4, as Mizzles can drop them infinitely via the Embezzle ACT.
- Enemy Scan: The Check option in the ACT menu returns from Undertale, letting the player get an enemy's Attack and Defense stats, as well as a short description of them. In Chapter 2 onwards, however, this info is relegated to the Recruits menu at save points, and thus the Check option only gives a brief description, which is lampshaded by its description in Chapters 3 and 4 calling it "useless analysis".
- Equipment-Based Progression: You can't level up, since enemies just run away after draining their HP. The main way to increase stats is via weapons and armor, though beating up enemies in Chapter 2 onwards can incite minor stat boosts at the cost of the enemy no longer being recruitable.
- Establishing Series Moment: The game begins with the player selecting between various appearances, likes, and a name. The game then tells you those choices "will now be discarded" because "no one can choose who they are in this world." This lets the player know what they're in for right away.
- Everytown, America: Hometown is a small forest town that has a tight-knit community, with a church and a school. It's such a peaceful, friendly community that the cops are basically useless (aside from an ineffective group of burglars), at least one character wishes for something interesting to finally happen, and the mayor faces no political competition because no matter how boring and uncharismatic she is, she's too good at her job to get rid of.
- Evolving Title Screen: After you beat each chapter, going to that chapter shows Ralsei's legend as the intro and changes the background (black with green text and boxes in Chapter 1, a Great Door in Chapters 2-4) to the cover art of Kris, Susie, and Ralsei watching a Dark Fountain.
- Exact Words:
- The Prophecy is shown to work like this, in a sense. While its exact wording is shown to be nigh-immutable, consequences leading up to it can alter the outcomes that aren't specified. For example, the passage "THE LORD OF SCREENS, CLEAVED RED BY BLADE" states that Mr. Tenna is destined to be cut down by the Knight, and his wounds are indeed fatal without immediate treatment. If the player has recruited the TV World denizens, however, they help Susie and Ralsei repair him between Chapters 3 and 4, and he ultimately pulls through with some superficial dents and a damaged antenna.
- This is hinted at by Gerson if you accuse him of deliberately breaking some of the prophecy panels in Chapter 4. He responds that while the words of the prophecy may seem like a nice guideline to work by, he'd much rather prefer to look in between the written lines to the unwritten dark space in between.
- A massive challenge when it comes to unlocking the Easter Egg gotten by having no Trophies by Chapter 4 in the PlayStation version is that the game exploits the extremely vague Trophy descriptions to hell and back to essentially trick you into getting at least one. One example comes from "CUTLERY 3-A/SYMPHONY 3-A", which is gotten by achieving a "superior rank" in the cooking and rhythm minigames respectively in Chapter 3. Contrary to what one might think, this means getting any rank other than Z, which every other rank is "superior" to.
- The Prophecy is shown to work like this, in a sense. While its exact wording is shown to be nigh-immutable, consequences leading up to it can alter the outcomes that aren't specified. For example, the passage "THE LORD OF SCREENS, CLEAVED RED BY BLADE" states that Mr. Tenna is destined to be cut down by the Knight, and his wounds are indeed fatal without immediate treatment. If the player has recruited the TV World denizens, however, they help Susie and Ralsei repair him between Chapters 3 and 4, and he ultimately pulls through with some superficial dents and a damaged antenna.
- Experience Points: Battles in Chapter 1 end by saying how many EXP you've earned, which will always be 0. As in Undertale, gaining EXP is Gaining the Will to Kill, something Deltarune only allows under very specific circumstances, and even then the game skips the EXP report entirely in favor of just saying "became stronger".
- Extremely Short Time Span: Most of the chapters start in the morning and end in the late afternoon/evening. Chapter 3 has the shortest timespan of all, taking place over the course of a single night. So far, 3 days have passed in-universe: Chapter 1 took place on Thursday, 2 and 3 on Friday, and 4 on Saturday.
- Eye Motifs: Eyes and vision are central themes, tying in with the overarching light/dark dichotomy. Among other instances, Several characters (e.g. Kris, Lancer, and Susie in Chapter 1) have Hidden Eyes that only rarely become visible, the player has to blind eyes as part of a puzzle in Chapter 1, Ralsei wears large glasses that accentuate his eyes, and in Chapter 2, Susie's bangs no longer cover her eyes outside of battle to cement her Heel–Face Turn.
- Fake Facial Hair: In the first chapter, Lancer disguises himself as a "sweet little boy" by wearing an obviously fake mustache in order to get Kris and Ralsei to design the Thrash Machine. He wears it again later in Castle Town's bakery, claiming to be "Chef Lancer" instead of regular Lancer.
- Family Theme Naming: The Christmas-themed Holiday family: Rudolph, Carol, December and Noelle.
- Fantasy Keepsake:
- The "Ball of Junk" item found in your Light World inventory is made up of your Dark World inventory (having at least one Dark Candy while leaving even makes the game mention of it smelling like scratch'n'sniff marshmallow stickers). The "Use" command prompts Kris to look at the ball in admiration, likely reminiscing about their adventures. When told to drop it they express hesitation to do so, and then extreme bitterness when successfully pressured, resulting in you losing all items and nonequipped weapons and armour that weren't in storage.
- Shadow Crystals remain in your inventory after leaving the Dark World, becoming a piece of glass. It seems ordinary until you try to use it. If Susie is following you, looking through it makes you see her coldly glaring at you, until you lower it and see she's actually smiling. If you're by yourself, looking through it enables you to see through your own hand. Using them in front of the prophecy panels in Chapter 4 has you seeing glimpses of what seem to be future events.
- First-Episode Twist: At the beginning of the game, you seem to be playing as Kris... until the end of Chapter 1, where Kris violently rips the SOUL out of their body, establishing that the SOUL and Kris are two completely different entities.
- Fisher Kingdom: The outfits of Lightners change when they enter the Dark World, as well as brightening their skin tones. And depending on just who makes a Dark Fountain, the colors can shift around.
- Kris' skin changes from dull yellow to light blue, and they change into a suit of armor. In the second Dark Sanctuary, the blue on their body becomes a paler shade and the pink stripe on their cape turns maroon.
- Susie becomes pink-colored, and wears a biker outfit. In the second Dark Sanctuary, her color scheme becomes brown and yellow.
- Noelle gets paler fur, and wears white robes.
- Berdly's feathers become slightly paler, the sclerae of his eyes change from white to yellow-green, and he changes into high-tech armor.
- Toriel wears a robe and crown fit for a queen, and Chairiel becomes a throne.
- Undyne's hair and scales become brighter and more vivid, and her uniform turns into armor.
- While we don't see what Gerson looked like when he was alive in this world, his skin turns a deeper green than it was in Undertale.
- Flushing-Edge Interactivity: The toilet in the Dreemurr household can be flushed multiple times; a fanfare plays when it is flushed. Do this enough times, and Toriel will ask Kris if they flushed a bath bomb again. Keep doing this, and she'll declare that they'll be footing the plumbing bill if the toilet breaks.
- Foreshadowing: A couple of Spamtons lines during chapter 2 (namely when asking about "Friends" at Spamton's shop, with him ranting "Don't believe [[Anything You See On TV]] The man's a criminal, I tell you! A criminal!" and his confrontation at the end of the Snowgrave route when he asks "What are you, a [Gameshow Host]!?") foreshadow Tenna, a gameshow host who happens to the Dark World leader of Chapter 3 and Spamtons former business partner.
- The Fourth Wall Will Not Protect You:
- Chapter 1 ends with Kris ripping their SOUL out of their chest, physically divesting the player of control over them, and flashing a Slasher Smile at the camera.
- Chapter 3's Sword Route sidequest provides two different In-Universe cases:
- Throughout the chapter, the Legend of Zelda-styled Game Within a Game has little physical bearing on its players. However, during the battle with the Shadow Mantle's holder, any damage Kris's game character takes is subsequently transferred to their actual SOUL, and will lead to a real Game Over instead of the console simply turning off.
- When the Shadow Mantle's holder is defeated, the chest containing the Mantle as an armor piece is too high for Kris's character to reach. The only way to collect it, and the only way to stop playing the Game Within a Game at all, is for you to control the game character outside the TV screen and toward the real Kris to stab at them, making them drop the controller so that the real Kris can walk *on* the screen to grab it. The 8-bit version of Kris then walks offscreen, but during the subsequent cutscene with Susie, you still have control of 8-bit Kris, and can walk back onscreen to stab Susie while her back is turned, causing Kris to frantically pull Susie out of the way.
- In Chapter 4 if the Dynamic Border is on, when the Titan is awakened by the Roaring Knight, the border changes to the giant pointed eyes associated with them, which flash red when the Titan is damaged during its battle.
- Freeze Sneeze: After visiting Noelle, it will start to rain. If you haven't brought Tenna to Castle Town by this point, the TV will be outside Kris' house waiting to be thrown out, getting wet in the rain. Susie will hurriedly bring it to the school and note that Tenna was sneezing and shivering.
- Gameplay Roulette: Even including all the mix-and-match gameplay elements that persist from Undertale, Deltarune goes even further beyond its predecessor in terms of stretching the definition of an "RPG" to its limits. There are platforming sections, obstacle courses, Shoot 'em Up sections, mech battle sections, minigames galore, minigames within the already extremely varied combat encounters, and even more miscellaneous mechanics that may only show up for a single sequence, battle or puzzle. This goes all the way up to including things like an Optional Boss that requires you to fight it by making sounds into your computer's microphone.
- Game Within a Game: The Dragon Blazers trilogy of games is mentioned on occasion, being a turn-based RPG with options for mercy and violence. A number of details from the games end up creeping into Deltarune itself, with Noelle, the Weird Route and the Sword Route getting the brunt of it, the third being greatly implied to be partially made of gameplay from Dragon Blazers III itself. It's later revealed in Chapter 4 to be an adaptation of Gerson's book Lord of the Hammer, which is itself an adaptation of the prophecy.
- The Ghost: Besides the Greater-Scope Villain(s), numerous characters are mentioned but unseen and unheard as of Chapter 4:
- Asriel is mentioned repeatedly by the residents of Hometown, but is stated to be away at college.
- Dess is mentioned in a sparse few lines of dialogue from both Noelle and Rudy, being the oldest daughter of the Holiday family. Numerous lines all but outright state she disappeared a few years before the events of the game, and a hidden page in the Spamton Sweepstakes urges you to "find her". You get to explore her room in Chapter 4, and it's heavily suggested that something bad happened to her.
- Papyrus, whom Sans requests that Kris play with. If you interact with the door of Sans' house, you will hear "the distant trousle of bones", but Papyrus' name still has not been mentioned.
- GIS Syndrome:
- Played for Laughs with the stock image of an almond milk carton that pacifist-enforced bosses (Chapter 1's K. Round and Chapter 2's Sweet Cap'n Cakes) use to restore their health if they take damage. A stock explosion GIF is also often used in place of proper art whenever an explosion happens.
- The TV World in Chapter 3 has these scattered about, such as the Ball Machine in the B-rank room and the prizes Tenna promises to give out to winners of his game show. One of these prizes is a real-life Ralsei plushie that can be bought from Fangamer themselves.
- Gosh Dang It to Heck!: Generally averted. Characters semi-regularly use PG-13 language like "damn", "ass", etc.
- Averted for laughs in Chapter 2:Queen: Why The Heck (Hell) Would I Want To End The World?
- During the tea party in Chapter 4, Ralsei nearly says "badass" when complimenting Susie before frantically amending it to "bad-bum".
- Averted for laughs in Chapter 2:
- Greasy Spoon: QC's, the local diner, where the Dreemurr family used to eat when they were all living together. Fittingly, the Southern-accented, kindhearted rabbit shopkeeper from Snowdin is the head waitress here, and calls Kris "hun".
- Half-Baked Niceness: Near the end of Chapter 1, Kris and Ralsei try to convince Susie to be nice towards their enemies. She doesn't get it. Ralsei tells her to try telling the enemy something that she would want someone to tell her. Susie then says things like "You are unbanned from free ham sandwich day", or "Please keep tackling the soda machine". Surprisingly, it actually works, and the enemies are able to be spared. Thankfully Susie's compliments do improve.
- Hammerspace: Kris can carry around a lot of stuff in their pockets even if it doesn't look like it should be able to fit with only a few exceptions. A notable example is when Susie asks Kris to steal a statue that looks like her from the room Queen made for Noelle, even though it's much larger than them.
- Hammy Villain, Serious Hero: Kris, although a bit strange, is stoic, quiet, and cynical, never showing any outward reaction to the weirdness of the Dark World. Many of the antagonists are all Laughably Evil hams:
- Queen is an Affably Evil Lady Drunk with a Noblewoman's Laugh and a larger-than-life personality, who likes blowing things up and making Big Entrances. Many funny moments are had when Kris and Queen interact, with Kris not even changing their deadpan expression as Queen goes on one of her tangents, leans on their head, or treats them like an old pal.
- Berdly, Kris' classmate and rival, is an Insufferable Genius with a big ego who uses overly sophisticated words to make himself look smarter than he is, and his portrait can go hilariously off-model during some of his lines. Pretty much all of his appearances have him be over-the-top arrogant, up to and including creating a giant, golden statue of himself with big muscles and nipples.
- Spamton is an insane, over-the-top Snake Oil Salesman who shouts at Kris with CAPS LOCK, Word-Salad Horror and an Electronic Speech Impediment to convince them to make a deal where Spamton takes their SOUL in exchange for something called [Hyperlink Blocked]. Unlike Queen and Berdly, he is considered creepy and off-putting, and his appearances are just as unsettling as they are morbidly funny.
- Tenna is a wacky and bombastic game show host with a flair for the dramatic. Most of the comedy surrounding him involves his over-the-top nature and his weird movements.
- Hard Truth Aesop:
- In stark contrast to Undertale, this game makes the point that some people are too unreasonable to be dealt with peacefully, even if you try your best to be nice or spare them. For such people, the only way to pacify them is through force. This aesop sees use in Chapter 1's Final Boss fight, where Ralsei's attempts at peacefully resolving the conflict with King nearly gets the party killed, and King is only able to be subdued either through magic or an outright revolution (depending on the player's actions).
- Conversely: Malicious people can be contained depending on the context, but never truly reformed. Jevil is imprisoned, but once released displays the same violent temperament Seam describes.
- Sometimes, no matter what you do or how good you are, you have no control over your situation.
- Have We Met Yet?: Back in Undertale, Sans' remarks about his original home, his accusations towards the "anomaly" and bothering at all to let Frisk stumble into the backroom lab of his house imply he expected the kid to know what he was going on about. In Deltarune, the SOUL is the one expressing through Kris curiosity about how people like Undyne and Sans are doing in this new world. To further muddle matters about what is happening, Sans denies knowing Kris while standing before a building that looks plucked right out of the original game's Snowdin.
- Healing Boss: To ensure that they can only be defeated through pacifism, both K. Round and Sweet Cap'n Cakes automatically heal all damage inflicted on them by drinking from an edited stock photo of Silk almond milk. Additionally, once The Titan’s HP depletes enough, it enters a nearly invincible state and begins recovering until it is at full health again.
- Health/Damage Asymmetry: The amount of damage the player characters can deal is easily more than half their health, and can reach more than double in the case of Susie's and Noelle's spells. Meanwhile, the most damage that an enemy can dole out is around a third of a party member's health bar, and their health bars are larger than the player's, with the superbosses having an order of magnitude more health than the entire party.
- Hello, [Insert Name Here]: Defied in the vessel creation intro in Chapter 1. The player is given the choice to enter multiple values for their character, only to have most of them discarded before the game starts. However, the name inputted as the player's own name becomes the name of the save file itself, which starts by overwriting a pre-existing file labelled "Kris"note . The save file name is also used in Castle Town in Chapter 2, which is named [name]Town.
- Hitbox Dissonance: To make grazing more exciting, many attacks are actually far smaller than they appear to be
, though the most egregious single example is probably Jevil's carousel attack — despite the animals' large size, the only parts that actually do damage are the areas just around the wings
, occupying only around a third of the sprites. This is a point of advice at the Castle Town Dojo in Chapter 2. - Holiday Motif:
- True to their names, the Holidays are a family of anthropomorphic reindeer themed after Christmastime. Noelle is named after Noël, the French word for Christmas, Rudy is named after the title character of Rudolph the Red-Nosed Reindeer, Carol is named for Christmas caroling, and "Dess," the name of Noelle's unseen sister, is short for "December". Rudy occasionally uses Christmas-themed wordplay (e.g. "jingle my bells") and has an angel tree-topper in his hospital room, while the month of December is ironically a Trauma Button for Noelle following the Noodle Incident that took Dess out of the picture.
- Jackenstein is a Darkner born from a Halloween decoration, and as such has a pumpkin motif. His boss fight involves traveling through makeshift haunted houses in the dark.
- Hopeless Boss Fight: At the end of Chapter 3, the Knight itself makes its first appearance. It seems like a one-sided fight at first, but the fight can be won if you acquired the right secret equipment. The Knight still pulls a Heads I Win, Tails You Lose, but you're rewarded with a Shadow Crystal and a very strong weapon for your efforts.
- Human Pet: One of the books in the library is a monster's guide for "How to care for humans". Upon inspection, Kris finds their mother borrowed it often when they were a young child, though they personally dislike the contents.
- Infinity +1 Sword: Each of the Heroes are able to obtain an incredibly strong weapon by defeating a powerful secret boss. Ralsei gets the Puppet Scarf by defeating Spamton NEO violently, Kris gets the Black Shard by defeating the Roaring Knight, and Susie is given the Devilsknife by defeating Jevil violently and the Justice Axe by defeating Gerson.
- Interface Spoiler: Noelle and Berdly become relevant to the plot in Chapter 2, but it can be inferred that they will be important beforehand as they have unique Voice Grunting and face portraits, unlike most of the other students and like characters from Undertale.
- Interspecies Adoption: Kris is a human who is adopted by the Dreemurr family.
- Interspecies Friendship: Kris forms some with Susie, Ralsei, and Lancer in the Dark World, and seems to get on well with some of their classmates.
- Intrigued by Humanity: The bunny monster children have an adorable fascination for how Kris is made up of flesh and blood instead of magic.
- It's All Upstairs From Here: Chapters 1 and 2 end with the heroes climbing up the Arc Villain's base to seal the Dark Fountain, though the greatest foes lie on the lowest floors of the base.
- It's a Wonderful Failure: If you choose "No" when asked to continue after dying, the voice from the intro describes that the world was covered in darkness, implying that your decision led to the Roaring happening.
- Joke Item:
- Dog Dollars are very poor Shop Fodder that get even less valuable over the course of the game, and are always gotten through gags involving the Annoying Dog.
- The Broken Sword, bought from Spamton in his shop (where it's corrupted to sound too good to be true) has the "Failure" equipment effect, meaning it can't be equipped at all.
- Rotten Tea, which is the state that all "[Character]" Tea items end up in if carried past Chapter 2, only heals 10 HP.
- Completing the Sword Route in Chapter 3 nets the player two unique items: the Shadow Mantle, a powerful piece of equipment that makes getting the chapter's Shadow Crystal easier, and a Flat Soda, which is just a half-empty can of soda Susie was drinking that only heals 20 HP.
- Kill the Brainwashed: The player can choose to fight the Werewires rather than sparing them. Werewires are explicitly Brainwashed and Crazy through the wires that are plugged into their faces. If they are attacked, they will be Lost, making them unable to be recruited. This also happens to Berdly, though if he is fought he eventually manages to fight against the brainwashing, though at the cost of his arm.
- Late-Arrival Spoiler: Deltarune spoils a few things about some of the endings for Undertale; perhaps most notable being the original game's twist of "the protagonist and the player are separate entities" being casually mentioned during the character creation screen, and explicitly shown at the ending of the first chapter. The game's official site does state it's "intended for people who have completed Undertale," and the narration that appears when booting up the console version for the first time reaffirms this, bringing up a prompt that allows the player to purchase Undertale if necessary.
- Leitmotif:
- The Leitmotif of Deltarune as a whole is called "Don't Forget
", and appears consistently across area themes in both the Light and Dark World. - "The Legend" leitmotif also shows up repeatedly, as the theme for (both versions of) Castle Town and in King's boss theme.
- Undertale's main leitmotif, "Once Upon a Time", shows up a few times as well (most notably in "You Can Always Come Home
", a reprise of "Home" from the original game), but only in the Light World. - Each chapter's main villain (thus far Lancer and Queen) has their own theme, which features prominently in their boss tracks (as well as King's boss track in Lancer's case), as well as any areas strongly related to them, like Card Castle or Queen's mansion.
- Some of the more plot-important Lightners also get their own themes, like Noelle
and Berdly
. Sans
also gets one, but his has been ripped whole-cloth from Undertale; like everything else about him. - Apart from the Knight, all Shadow Crystal holders, the game's once-per-chapter superbosses, have their own associated leitmotif (dubbed the "Freedom Theme" by fans) which has made an appearance in each of their overworld and battle themes. The Freedom Theme in turn is a variation on "Gaster's Theme", a short, four-note tune first introduced in the Sound Test Room from Undertale.
- "BIG SHOT", Spamton's second boss theme, consists of four leitmotifs: his own, the "Freedom Theme" described above, and two from Undertale: the "Battle Against a True Hero"/"Power of NEO" theme, and the "Dummy!" theme.
- The leitmotif that plays in the Basement where Kris encounters Spamton NEO is also taken from Undertale. It's the "Your Best Nightmare"/"Burn In Despair!" motif, which implies a connection with Asriel.
- The "Lost Girl" theme, introduced in Chapter 2, used to be associated with Noelle. Chapters 3 & 4 see it become its own theme; it's used in Susie's backstory, during the scene in Ralsei's room in Chapter 4, etc. It's also featured in the chorus of "Raise Up Your Bat", a song that's implied to be associated with Dess and, interestingly, "Black Knife", the Roaring Knight's boss theme.
- One of Spamton's leitmotifs from Chapter 2, HEY EVERY, is revealed in Chapter 3 to actually taken from the opening of Tenna's leitmotif, deepening the connection between them.
- Mike's boss fight includes at least three separate leitmotifs – Spamton, Tenna, and Queen, with more if you look deeper – as part of Toby's acknowledgement of all the fan theorizing over who exactly Mike was.
- The Leitmotif of Deltarune as a whole is called "Don't Forget
- Lethal Joke Item: The Lancer Cookie's description mentions it only restores 5 HP, which is reduced to 1 HP in Chapter 2. This is the amount the cookie heals in the overworld, but in battle, the cookie heals 50 HP.
- Lighter and Softer:
- While Deltarune as a whole is more cynical and depressing than Undertale, it has yet to get nearly as dark as Undertale's darker moments on the Normal Route, primarily because violent options result in a Non-Lethal K.O. at best, and a minimal modification of the post-boss scenes at worst. The Weird Route averts this, culminating in the player forcing Kris to psychologically torture Noelle in the Light World and force the Thorn Ring onto her.
- On a more specific level, while most of the Darkners actively antagonize the heroes and at least two actively want to kill them (that being King and Jevil), they aren't openly out for Kris's SOUL; with Spamton as the one exception.
- Liquid Darkness: zigzagged: Throughout the game, there are multiple allusions between darkness and water. The source of the dark worlds are called "dark fountains." When first entering the dark world in chapter 1, the sound of waves can be heard, and the audio file is even named ocean.ogg and the dark fountains are shown with an edited texture of water. However, the presence of a dark world in the light world is shown with black smoke emerging from the source.
- The Lonely Door: The Dark Worlds of Chapters 1-3 have a fast-travel system in the form of a standing Warp Door with a fire flickering under it. Most of the Warp Doors in each Dark World are empty and unusable until the party travels through the one that is active.
- Lonely Piano Piece: If the player chooses not to continue if they die, one called "Darkness Falls" (a melancholic version of W.D. Gaster's leitmotif) plays.THEN THE WORLD
WAS COVERED
IN DARKNESS. - Lord British Postulate: Invoked. This is the entire basis of the Weird Route. After spending all of Chapter 1 and up to when Noelle is recruited in Chapter 2 completely unable to kill anyone, the player twists the game's mechanics to actually find a way to do it.
- Magic Skirt: Well, Magic Robe in this case. Even when he's completely upside down, Ralsei's cloak doesn't budge.
- Magical Land: The Dark World is a land created by a Dark Fountain in the regular "Light World" that is shaped by items nearby the Fountain.
- Mana: Tension Pointsnote are collected by either grazing bullets or defending, and are stored in an orange meter as a percentage. TP can then be used on spells such as Pacify or Rude Buster, as well as certain ACTs.
- Mana Potion: Tension Bits and Tension Gems grant amounts of TP when used. They come in handy during Chapter 4, where Jackenstein and the Titan's fights severely reduce TP gain from other sources.
- Medium Awareness:
- Both Jevil and Spamton aware that they are in a game, and gaining that awareness drove them both insane.Seam: Soon, [Jevil] began to see the world as a game, and everyone as its participants.
- Kris is aware that the player is controlling them, and can forcibly remove that control at times. It's unclear if Kris knows that they are literally in a video game, or their awareness of the game mechanics beyond that.
- Ralsei describes the game mechanics to you, which Susie is confused by, and appears to take advantage of them at times for his own unknown ends.
- Both Jevil and Spamton aware that they are in a game, and gaining that awareness drove them both insane.
- Mind Screw: The more information is provided about the Dark World, the more it turns into this. At first, it's implied that the Dark World is a Wonderland-esque alternate plane of reality where inanimate objects and concepts have analogous living counterparts, with some Synchronization existing between the two. This is true, but the explanation Ralsei gives in Chapter 3 reveals it's not the whole story. The Dark World is described more directly as the logical extreme of how darkness obscures the true form of things, where it's possible to have so much darkness that reality itself distorts to create the Darkners and the Dark World itself out of things from the Light World; in other words, it's an incredibly lucid illusion. What this doesn't explain is how the Dark World is able to have real tangible effects on the Light World, implying it isn't just an illusion, but nothing else is revealed about it as of yet.
- Mood Motif: A lo-fi filter that cuts off high frequencies is used at the beginning of each Dark World overworld track ("Field of Hopes and Dreams" and "A CYBER'S WORLD?"), with the rest of the song featuring a fuller, clearer sound; concurrently, the instrumentation shifts from a single instrument to a much beefier arrangement. The transition between these portions symbolizes the shift from the mundanity of the Light World to the vibrancy of each Dark World.
- Mundane Made Awesome: Your Dark World equipment is just boring stuff like pencils, scented stickers, and other assorted junk that can all fit in Kris's pocket. Entering the Dark World transforms it into usable gear like swords and armor.
- Mythical Motifs: Some real world cosmological and mythical ideas are borrowed and altered for this game.
- Yin and yang references are a minor theme in the game, fitting its similarities to Shinto and Taoism. Drawing upon Japan's interpretation of yin and yang, the Darkners in the game are similar to folkloric entities known as shikigami, who can be paper dolls brought to life, ghosts, or some kind of animal. This fits the descriptions of most Darkners (though they are actually all kinds of objects brought to life), Gerson, and possibly Friend.
- Shikigami in Japanese folklore were thought to be controlled by onmyōji, loremasters who saw the world as a product of yin and yang as well as the 5 phases or elements. The Deltarune world has both light and dark sides that need both of them to function in harmony with their natures and various elemental powers that Darkners use. The onmyōji also drew power from time and the calendar, which fits the day-based nature of the Chapters and the temporal weirdness of the SAVE points, three Dark Worlds and their characters being relevant to each other before they are even created, and WD Gaster's possible involvement in the story as a force of darkness or yin being juxtaposed with the influence of the player, a force of light or yang.
- More general yin and yang references with elements not exclusive to Japan include some traits of Noelle and Spamton. Noelle is somewhat distant from the world and associated with ice, coldness, being passive and controlled by her feelings, literal darkness symbolism such as the night in Cyber World and metaphorical symbolism such as being lied to a lot, and wanting a missing sister who may or may not still be in the Light World back (distance from reality, metaphorically and literally, basically). All of these are yin motifs. Spamton seems to have nothing to do with her at first, being masculine, a lover of the world's definition of success without taking into account the feelings of others, obsessed with his idea of heavenly power from a Lightner, and extroverted, with references to Toy Story's The Big One rocket and the sun in scenes showing him as more connected to warmth than cold. All of these are yang traits. However, Noelle was vital to Spamton's story, being the only one to pay attention to his messages before he became a Big Shot. Noelle's video game also led to the existence of the Pipis, key items to Spamton that he loved even at his height. Both of them were vital to creating the lore of the first three Dark Worlds, and their influence even extends somewhat to the incomplete knowledge of Gerson in Chapter 4, as he discusses the pattern of pink and gold in the Dark Worlds and is at least slightly aware of a Weird Route. Yin and yang together create the world in many Chinese and Japanese philosophies. Noelle even loves an embodiment of yang despite and because of her being very different from Noelle's personality: Susie, a dragon who can seize control from the player sometimes.
- Also, the influence of the player on Kris and a Weird Route Noelle can be seen as a yang overload according to traditional Asian medicine due to red being a color associated with yang, and that side of the dynamic being the one about active control and being in the world.
- The small-town religion being more about the heroes than the god figure of the Angel and existing alongside at least one other belief with more concrete concepts of sin is similar to some small-town Taoist organizations that worship deified heroes in China.
- Mythology Gag: Has its own page.
- Nap-Inducing Speak: While you can't read the Manual, you can use it in battle to make enemies Tired and vulnerable to Ralsei's Pacify spell.
- Negative Stat Value: The playable characters will dip into negative health points when they die, a status referred to as "Down". While Downed, they will slowly regain HP until it becomes a positive number again and they can get back up. The Roaring Knight inflicts "Swoon" instead, where any attack that's strong enough to KO Ralsei or Susie will immediately reduce them to -999 HP and prevent health regeneration, with only a Revive Mint or Revive Dust reasonably capable of bringing them back.
- Nerf:
- Like Undertale, damaging enemies without depleting their health allows you to defeat them peacefully. However, instead of being put in an immediately spareable state, enemies get tired, requiring a spell to be taken out of combat.
- The Pink Ribbon (as well the Twin Ribbon it can be crafted into) increases the SOUL's graze area when equipped, letting it gain TP from passing bullets at a longer distance. This is a strong effect even for a well-hidden equip, so starting with the release of Chapters 3 and 4 it gained the hidden drawback of reducing TP gain from grazing bullets, making it into "low risk, low reward" equipment that necesitates grazing more bullets for the same efficacy.
- New Game Plus: After completing a chapter once, you can skip its opening Hometown section by returning to bed and accepting a warning prompt that will ask you to confirm if you're sure, since you will miss a lot of story content.
- New Work, Recycled Graphics: While most of the content of Deltarune is brand new, there are minor elements recycled from Undertale. The Heart/SOUL (though it has a different sprite in Bullet Hell segments), the Annoying Dog/Toby Avatar (during most Dogchecks), and Sans all reuse their previous sprites, and the Light World's UI is directly carried over from Undertale.
- Nice, Mean, and In-Between: Kris, Susie, and Ralsei form a trio like this. Ralsei is the nice one, being the most pacifistic, gentle, polite, and affectionate of the three, even to his enemies; Susie is the mean one, being rude, brash, aggressive, and cruel (at least at first); and Kris is the in-between one, since they are stoic and because you control their actions.
- The Noisy Straw: In Queen’s room in Chapter Four, she drinks from battery acid. As she talks, she frequently pauses, a loud slurping sound playing as she does.
- Non-Elemental: The majority of bullets are classified in the code as element 0, which is not affected by any resistances from armor.
- Non-Lethal K.O.:
- Enemies flee or get blasted away when out of HP. Notably, EXP is unattainable by any method, as it presumably still stands for "Execution Points" as in Undertale, and none of the player characters ever kill anyone (and in the one specific situation when anyone does, XP gain isn't actually listed).
- When player characters' HP hits zero, they are merely rendered unconscious istead of killed; Ralsei lampshades this if you use a Revive Mint on Susie:Susie: I'm ALIVE!!!Ralsei: (You weren't dead)
- Noodle Incident:
- Toriel and Asgore still had a falling-out in the past, but this time, what actually caused it isn't explained.
- Asgore was formerly the chief of police. Some unspecified incident forced his removal, and subsequent replacement by Undyne. If the player inspects an article about it, Kris will close their eyes, refusing to read the contents. It's implied that the incident that led to his removal also led to his and Toriel's divorce.
- Noelle's older sister Dess was a close part of her and Kris' childhood, but whatever happened, she's completely gone now. The game heavily hints that she disappeared, which traumatized Noelle and possibly Kris, and the Sweepstakes event urges players to "find her".
- Kris apparently did some interesting things in their past. Some are described by the residents of Hometown, while others, such as hiding under Noelle's bed to scare her and putting a bath bomb in the toilet, only get a mention, leaving the details to the player's imagination.
- At the end of Chapter 2, Monster Kid and Snowy allude to some kind of urban legend regarding the shelter at the southern edge of Hometown and something that happened to Kris there. Whatever it was makes Snowy mock Kris for being a scaredy-cat. When the secret game in Chapter 3 suddenly shifts to a simulacrum of the shelter, Kris will begin fighting against the player's control as they approach it.
- Not Completely Useless: FIGHTing (and dealing damage in general) is this in some spareable encounters. While most non-Titan enemies (sans GIGA Queen) can be defeated without pressing the FIGHT button, it can be used to end the King fight early without affecting the ending and Susie's Buster spells take down Queen's acid shield a lot quicker than ACTing will without getting Berdly injured.
- Nothing Is Scarier:
- The desolate gray valley Kris and Susie find themselves in when first entering the school's Dark World. There's nothing but a few odd little creatures, piles of what seems to be dust and bleeding eye symbols in the walls. When Ralsei explains the prophecy of the Titans later, those eyes are seen as part of one of their bodies. As of Chapter 2, nothing is said about either the valley or what the locked room to the west of the storage room could even be to contain such a thing.
- The shelter. A rusty red door located south of the town, after a long trek through a path, during which no music plays apart from the Entry 17 ambient noise from Undertale, slowed down by 666% to mimic humming machinery. Accessible as early as Chapter 1, it is closed most of the time and while revealed to contain a Dark World in Chapter 3, whatever is inside remains a mystery.
- The pitch-black mazes in the Dark Sanctuaries, especially the first one, where the party is stalked by an unidentifiable creature — retroactively implied to be a Titan Spawn — making unnerving noises.
- The prophecy itself. It becomes progressively more clear that something horrible is fated to happen at the end of it, which bodes very poorly for the main trio. However, the player never learns the truth of it before Susie smashes the mural depicting it, leaving the true horror of it to their imagination.
- Nothing Exciting Ever Happens Here: Kris and Susie's home town of Hometown is a small community where everyone knows everyone else. Police Chief Undyne, in particular, seems rather upset that the town is so peaceful.
- NPC Boom Village: As you recruit more monsters, Castle Town becomes more lively.
- Numbers 2 Names: The main antagonist of Chapter 2, who is a laptop in the Light World, introduces herself as Serial Number Q5U4EX7YY2E9N before saying that it's shortened to "Queen".
- Numerological Motif: The numbers 17 and 666 are used in the game's data to imply a connection with Dr. W. D. Gaster, as they did in Undertale. The shelter door uses the room ID 17 and plays a muffled version of the "garbage noise" from Entry #17, slowed down by 666%. The Voice's dialogue in the Survey is printed on-screen with ID 666, which was formerly used for Gaster's Wingdings text. The Chapter 2 demo was released on the 17th of September.
- Obvious Rule Patch:
- During Chapter 1, the Manual is secretly a Lethal Joke Item because it can be used to make a number of enemies Tired, which lets Ralsei cast Pacify to spare them without needing to go through the normal process. To prevent this from becoming a dominant strategy for the rest of the game, returning to Castle Town in Chapter 2 secretly removes the Manual from your inventory, and Ralsei places it in Kris's room in the castle where it can never be picked up again.
- In the Cyber World, the player can buy "character tea" from one of the Addisons, which can be flavored as any of the four characters available in the chapter, and heals different amounts (and with different flavor text) depending on how the drinker feels about the character whose tea they're drinking. The developers anticipated that detail-hungry players would likely hoard the tea and use it at every juncture as character relationships shifted, and pulled a trick to avoid having to account for that for the rest of the game: after Chapter 2, all tea items degrade into "Rotten Tea" from how cheaply made they are, and only heal 10 HP across the board.
- Odd Organ Up Top: In Hometown, the receptionist at the town hall has a manicured hand for a head.
- Odd Friendship:
- Jockington and Catti's relationship. One's a sullen goth and the other is a Cloudcuckoolander jock, but they both like each other a lot.
- Noelle and Kris were childhood friends despite the former being an easily-frightened Extreme Doormat and the latter being an unsociable Creepy Child who loved scaring her. Somehow, Kris was one of the only people she felt comfortable around. Chapter 2 sees them rekindling their friendship, for better or for worse.
- Two minor NPCs in Chapter 3 are a swindling Pippins and a rule-abiding Zapper who have become friends. At the end of the chapter, the Zapper has turned to stone (since Kris nicked him from the Cattenheimer household) and the Pippins begs Kris to seal the fountain so they can be reunited again.
- Oddly Small Organization:
- The kings of the Card Kingdom; the Diamond King had the Rudinns and the Rudinn Rangers and the Heart King had the Hathies and the Head Hathies, whereas the Club King had only Clover and the Spade King had only Lancer.
- The only cops in town are Police Chief Undyne and Officer Napstablook.
- Off the Rails: The Weird Route, an alternative story path that is accessible beginning from when Noelle joins the party in Chapter 2. While the game mandates that "your choices don't matter", this route features heavy Loophole Abuse from the player to ensure otherwise. During the short time that Noelle is your party member, she will obey your every order, even if it's what she doesn't want. By forcing Noelle to repeatedly kill Darkners with her ice magic and thus gain EXP, the player is able to make her grow stronger and stronger, increasing her lethality over time. At the same time, the forcing of Noelle to kill causes her timid personality to erode over time. The climax comes during the encounter with Berdly, wherein the player forces Noelle to cast a new spell, SnowGrave, that freezes Berdly solid. This is revealed to have left him comatose in the Light World, and further effects can be seen in Chapters 3 and 4. Whether this leads to an alternative ending is yet to be seen, but dialogue from Ralsei in a Weird Route Chapter 4 playthrough strongly implies that it will.
- Old Save Bonus: Whenever the player finishes a chapter, a completion file for that save file is created, which can be used to continue progress when starting the next chapter.
- Items and money from the previous chapter carry over, averting Bag of Spilling.
- Talking to NPCs in the Hometown epilogue will change some of their dialogue and actions in the next chapter.
- Once an Episode: Chapters 1-4 all have a scene where Ralsei asks Kris to close their eyes and imagine what Susie is doing, drawing the SOUL's attention away so he can talk to Kris about something without your awareness. Starting in Chapter 2, it becomes possible to disobey Ralsei, as if the SOUL is catching on to the trick. In Chapter 4, keeping with the theme of breaking trends, Ralsei is actually using this period of unawareness to search for and destroy information about the end of the prophecy, which he doesn't want his friends to see.
- Order Versus Chaos: A reoccurring conflict throughout the chapters, with the Arc Villain usually being on the side of Order and the Secret Boss inclining towards Chaos. The game does not especially favor one side over another, but rather seeks to explore the negatives and ramifications of both.
- In Chapter 1, King is a cruel and merciless tyrant who rules Card Castle with an iron fist, resulting in his subjects despising his rule and even his own son ultimately overthrowing him. His Chaos counterpart is Jevil, who became so obsessed with the concept of chaos and freedom that he went dangerously insane, to the point he can only speak in near-incoherent rambling, and ended up being locked away by his old comrade.
- In Chapter 2, Queen sees her authoritarian ways as beneficial for her subjects: she knows what's best, so everyone will be happier even if she forces them to do as she bids. This ultimately backfires as the more heavy-handed she becomes, the more her reluctant allies begin to turn on her. Her Chaos counterpoint is Spamton, who seeks to become truly free and escape his destiny as a failed salesman by utilizing dark forces he doesn't comprehend, which drives him insane and ultimately leads him to a worse fate than when he'd begun.
- In Chapter 3, Tenna is a Bad Boss who sees it as his duty to make Kris happy, which he does by trapping them in tightly controlled games that swiftly wear out their welcome, and his sanity plummets as he realizes he can't force people to love him forever. The Chaos counterpoint is Ramb, who, while not a boss, is heavily associated with the Shadow Mantle quest which must be completed in order to fight the Roaring Knight on an equal footing. Ramb encourages Kris to be free and to do whatever they want, and the secret game he pushes Kris to play ultimately turns out to be both physically and mentally harmful to them.
- In Chapter 4, while there is no direct antagonist (other than the Knight itself, who is rarely seen), the prophecy itself takes its place as the Order representative: it predicts everything and seemingly cannot be changed, even as it foretells a horrific fate for the heroes; the strain of knowing the prophecy in full and the fatalism of his belief that it is immutable takes a serious toll on Ralsei's self-esteem and mental health. By contrast, Gerson teaches Susie the dangers of surrendering and blindly accepting fate, and encourages the heroes to "go between the lines" and write their own futures. Notably, Gerson refused to use the Shadow Crystal he was given, showing he has a healthy understanding that while some chaos is good, it's possible to go too far.
- Outside-the-Box Tactic: Starting with Chapter 2, attempting to spare an enemy whose name isn't yellow yet will still fill their Mercy meter by a small amount, to ensure that the attempt wasn't a complete waste. This is typically a non-factor and doesn't even work on non-recruitable bosses, but there are rare battles where ineffective sparing will increase Mercy faster than using S/R-Actions, and even rarer ones where it can outpace ACTs altogether Example.
- Pacifist Run: Enforced. Since reducing enemies' HP to 0 does not kill them, whether a playthrough is "pacifist" or not depends on if you resolve battles peacefully or through non-lethal force. Consequently, doing one or the other has much less of an impact on the story than in Undertale. Certain bosses are outright impossible to bring to 0 HP or spare, killing any strict violent/merciful runs of the game then and there. Only through going completely Off the Rails in Chapter 2 can the player instigate something similar to the Genocide run of Undertale.
- Painting the Medium:
- The game's UI elements are styled differently between the Light World and Dark World, emphasizing the plain, everyday nature of the former and the enticingly unusual nature of the latter.
- In the Light World, text boxes and menus are styled identically to Undertale, consisting solely of black boxes with plain white text and borders, with menus being segmented into multiple boxes in the vein of EarthBound. In the Dark World, a more advanced menu divided into drop-down tabs is used, in-game text features a subtle blue drop-shadow, and text boxes have a fancy silver border.
- Lightners have monochrome portraits like in Undertale, while Darkner portraits are in full color.
- Permanently Missable Content:
- Played Straight with most of the things in individual Dark Worlds, which cannot be revisited once completed — this is particularly true of Chapter 2, where it's possible to save after returning to Castle Town, locking yourself out of the Cyber World for good on that file (which the game warns you about).
- Played With regarding the Shadow Crystals and equipment dropped by superbosses; if you beat them on one save, their rewards will appear in the hole to the left of Castle Town in save files occupying the same slot as the original save. However, this logically requires having defeated them in the first place, so you can still permanently miss these items on your first playthrough. The main advantage of this mechanic is that if you do miss a superboss but proceed with the game regardless, you will at maximum only have to replay that specific chapter to claim the rewards permanently, rather than needing to redo all the later chapters to carry them forward.
- There's a bit of code in the Chapter 4 credits that causes the Mysterious Voice to make a comment if the player has completed all four chapters on PlayStation without earning a single trophy. Earning these awards can't be undone, so earning a single one of the game's Effortless Achievements will lock out this special comment forever.
- Personality Mechanic: Your party members will gain more HP from eating foods they like, and less HP from eating foods they don't.
- Kris loves chocolate and gets 80-90 HP from eating a Choco Diamond. They get 10-20 HP from eating a Hearts Donut, possibly because its shape reminds them of the heart-shaped SOUL controlling them. In the early parts of Chapter 4, if you fulfil certain conditions, you can obtain the Ancient Sweet, an old chocolate that was left in Asriel's clothes. Since Kris idolizes and misses their brother, the Sweet heals a whopping 400 HP for them.
- Susie is a Big Eater and a Blood Knight. She loves Hearts Donuts and gets 80-90 HP from them because the red jam reminds her of blood. But she doesn't like Choco Diamonds and gets 20-30 HP from them, as they're implied to be rather small (her reaction to being given one is "That's it?").
- The "[Person] Tea" items in Chapter 2 have healing dependent on the level of friendship between the recipient and the person the tea is based on. Example, Susie gets a consistent 120 HP from all teas because she was lonely before, but now she has friends she cherishes. Noelle gets 400 HP from Susie Tea, by far the most that anyone gains from a tea item, due to her massive crush on Susie. Another interesting observation is that Kris only gets 60 HP from Ralsei Tea, a relatively low amount, which might suggest that Kris's true feelings regarding Ralsei are complicated and not overtly positive, perhaps given his resemblance to Kris's brother. When a character drinks their own tea, they are healed a pitiful 10 HP and remark that it just tastes like water.
- Player and Protagonist Integration: Building on Undertale, the game continues the implication that the Player Character is literally being controlled by the player (or an in-universe entity that controls them). Not only that, as the game expands to having you control a team, you for a short time leave Kris's perspective to follow a party member that separated from them with a lesser degree of control/guidance.
- Player Death Is Dramatic: Just like Undertale before it, if the HP of all party members in battle reach 0, everything will vanish except for the SOUL, which then cracks and shatters into pieces. This is actually played with, since Kris does remove the SOUL from their body plenty of times without dying, but the SOUL is the representation of the player's will, so if it breaks, the game is over anyway.
- Player Nudge: GIGA Queen in Chapter 2, the Knight in Chapter 3, and the Titan in Chapter 4 all cannot be spared, and are only able to be defeated through combat. In all of these fights, the Mercy meter is crossed out, to tell players not to waste their time trying to fill it.
- Playing Card Motifs: The Card Kingdom. King is the King of Spades, Lancer is the Jack of Spades, the Rudinns are diamonds, the Hathys are hearts, Clover is a club, Jevil is the Joker, and Rouxls Kaard is the rules card (as in, the card that comes with a deck that teaches you how to play cards).
- Point of No Return: Forcing the Thorn Ring on Noelle in Chapter 4's Weird Route is the point in which it becomes impossible to abort the Weird Route. At any prior point, you could abort the Weird Route at the cost of NPCs being upset at you. Just to rub in that the SOUL crossed the Moral Event Horizon, an even longer version of the Weird Route jingle plays upon shattering Noelle's sanity.
- Poorly Lit Pareidolia: The existence of Dark Worlds and Darkners is essentially an exaggeration of this trope. In normal darkness, the line between inanimate and sentient is blurred — such that a chair could look like a monster, or a poster could start moving on its own. In an even darker darkness that can only be created by the Dark Fountains, they fully transition into living creatures, becoming Darkners.Ralsei: You see, when it gets dark... Things become more indistinct. A chair can look like a monster. A poster can look like it's moving. Your eyes can't see the truth anymore. And when the light runs out... You see nothing. Of course, your mind can't make anything of nothing. But what if? What if it became even darker? Darker than dark. [...] If that were to happen... You could start to see things again.
- Poor Man's Porn: The "How to Draw Dragons" book in the Dreemurr house contains an immodestly-dressed dragon on the cover. The narration mentions it will never be returned to the library.
- Power-Up Letdown: If the heroes recruit enough Darkners from the Cyber World, then Seam will start selling Sweet Cap'n Cakes' CD Bagels in Castle Town in place of Dark Candies. CD Bagels heal double the amount that Dark Candies do, making this a good upgrade... until Chapter 4 starts, whereupon all Dark Candies turn into Darker Candies and start healing for more than CD Bagels do. Seam only starts selling Darker Candies at this point if they haven't already stocked CD Bagels (albeit at more than double the price), making this a rare disadvantage for players aiming to recruit every enemy.
- Pre-existing Encounters: Unlike the Random Encounters in Undertale, all battles occur from on-field enemies rushing toward you.
- Product Displacement: The self-heal move used by a few bosses is pretty transparently a carton of Silk-brand almond milk based on the design, but look closely and you'll notice that the pixelated text reads "Milk" instead of "Silk".
- Product Placement: The official Ralsei plush from Fangamer makes a few appearances in Chapter 3, with one quiz question even requiring you to guess its price.
- The Prophecy: Ralsei talks about one at the very start of Chapter 1, which is replayed as the intro when selecting a completed chapter on the main menu. He later expands it at the end of Chapter 2 and the Dark Sanctuaries in Chapter 4 elaborate on it further.
- The first part talks about how an imbalance in the forces of light and dark would bring a great calamity on the world, before three heroes — a human, a monster, and a Prince of Darkness — seal the Dark Fountains and banish the Angel's Heaven, saving the world. Ralsei believes that he, Kris, and Susie are those three heroes.
- When Berdly is about to create another Dark Fountain, Ralsei reveals the consequences of filling the world with darkness. The world would fall into chaos, with the Fountains forming Titans that devastate the land. Eventually, Darkners would be crushed by the darkness and turn into stone, and Lightners would be left to fend for themselves — an event which is known as the Roaring.
- Chapter 4 reveals that Ralsei deliberately gave a rather abridged version of the prophecy and specifically was hiding the last portion of it. When Susie sees it against Ralsei's best efforts to hide it, she smashes it with her bare fist, causing it to bleed, and tells Ralsei that there is no way any of them would let it come to pass as stated. Though even having said that, she's clearly still disturbed by it when on her own at the end of the chapter. The player remains in the dark about what it entails, however.
- Prophecies Rhyme All the Time: As shown in Chapter 4, most of the prophecy rhymes, but the player can find pieces of it that don't.
- Railroading: Discussed. As a contrast to Undertale remembering every choice and changing things based on player decisions, sometimes to a truly dramatic extent, Deltarune goes to great lengths to try and convince the player that everything they do does not matter at all. One of the central themes of Deltarune, as referenced by Arc Words, is that "your choices don't matter".
- In Chapter 1, regardless of whether you attacked everyone or spared everyone, the outcome is the same. Kris and Susie escape the Dark World, Kris pulls out the SOUL in their bedroom, and Susie has a Heel–Face Turn.
- Chapter 2 is a little less strict about the need to Follow the Plotted Line, but it still has every event play out largely the same, even though defeating enemies with violence or ACTing now affects the population of Castle Town.
- Called into question by Chapter 4, who has Gerson wisely tell Susie to consider making her own path rather than heeding every word of the prophecy, which distracts her from what's really important. Ralsei himself wants to believe that there is a way to change fate and there isn't only one ending, but fears that a different ending might be even worse. Whether or not this means the game itself won't have a single railroaded ending remains to be seen.
- Rainbow Speak: Important words tend to be colored either yellow or red. Special nouns are also put in all caps, most prominent being the KNIGHT and the FOUNTAINS OF DARKNESS.Seam: Historically, this land was ruled by the Four Kings, from CARD CASTLE to the East. But, recently, a strange knight appeared… And three of the kings were locked away.
- Recurring Riff: Just like in Undertale, there are riffs that are used throughout the entire soundtrack, including a few from Undertale itself. The most used riff so far seems to be of "Don't Forget", though there are also many likely instances of Gaster's theme
. - Recycled Soundtrack:
- The theme that plays when a new character joins the group is re-used from Fox's soundtrack for Rose of Winter.
- The track April 2012 is re-used from the soundtrack to a Homestuck game engine.
- Multiple Undertale soundtracks are reused in random snippets of each chapter.
- Red Eyes, Take Warning: Not only is Kris themselves shown to have glowing red eyes and is of ambiguous alliance to the party and the SOUL, this also applies when other Lightners open Dark Fountains, as shown when Susie's eyes briefly flash red as she opens one in order to bypass a locked door in the Light World.
- Regenerating Health: When a party member's HP is depleted, their health will be set to -50% of their maximum. Their HP regenerates by 13% each turn, reviving them in four turns (at 17% of maximum) unless the player uses healing to speed up revival. The "Swoon" status effect, which is applied by a few select attacks (all of them used by the Roaring Knight as per Chapter 4) is an exception, as it puts the downed party member to negative 999 HP and prevents regeneration altogether, with only a Revive Mint or Revive Dust capable of bringing them back.
- Respawning Enemies: Going back into a room that you've previously cleared of enemies will have them show up again in the same places, and you will have to fight them again if you cannot escape them. Justified here as reducing HP to 0 is a Non-Lethal K.O., so even in the worst of circumstances, nobody dies. This is also lampshaded if you repeatedly fight the very first Rudinn, with the game's narrative text repeatedly insisting it's a different one each time with incredibly minor (and not visible in-game) differences.
- Reused Character Design: Aside from the Costume Evolution, most characters returning from Undertale who didn't get an Age Lift use the same designs. Sans is one of the very few characters who didn't even receive a Costume Evolution.
- Rewatch Bonus: In one of the most bizarre moments of Chapter 2, if Kris talks to Spamton at his shop, he will offer to share information about the Knight, only to start freaking out and apologizing, then inexplicably reference Burgerpants' line about hell and vacation days from the Genocide Route of Undertale. This interaction long remained cryptic (with many fans assuming that Spamton was being threatened into submission by some unseen higher figure) until the context was subtly added in Chapters 3 & 4: it's likely that Kris (being in cahoots with the Knight) was the one threatening Spamton at his own shop, and Spamton's quoting of Burgerpants is a reference to the other time a shopkeeper was threatened by a player character.
- RPG Mechanics 'Verse: The Dark Worlds operate by RPG logic, with turn-based combat encounters, treasure chests full of loot, merchants selling and buying items, and so on. It's not commented on much while within the Dark Worlds themselves, but Noelle mentions that her dream seemed like a video game, and both she and Gerson are initially confused when they find themselves caught up in battle.
- Ruder and Cruder: Characters' swears are stronger here than in Undertale, most notably Susie infrequently talking about thrashing asses, Rouxls Kaard's infamous "GOD DAMMIT", and Spamton being a full-on Sir Swears-a-Lot. This is likely the main reason why, unlike Undertale with its ESRB rating of Everyone 10+, Deltarune is rated Teen.
- Running Gag:
- The "smells like (something)" in-battle description returns from Undertale.
- Susie getting increasingly annoyed every time you find a new ribbon and try to equip it to her.
- Kris eating moss.
- Photorealistic .gif explosions are used instead of pixel art almost every time something explodes, with a stock explosion sound accompanying them.
- Whenever you encounter an enemy party where all three enemies are different from each other in Chapters 1 and 2, the battle flavor text will read "Smorgasbord" in Chapter 1 and "Smorgasbord 2" in Chapter 2.
- "How to Draw Dragons", an innocuous book whose main appeal is the provocatively dressed purple dragon girl on the cover.
- "Mamma mia" shows up a lot whenever somebody is in distress, with Top Chef's general misfortune being consistently Played for Laughs, Tenna's Freak Out upon seeing Spamton featuring a lot of "mama"s and "mia"s, and Jackenstein's pumpkin babbling in Mario-esque gibberish including a very audible "Mamma mia".
- Someone landing on Ralsei with a cartoonish splat noise.
- Ralsei being used as a stool. And getting increasingly more fine with it.
- After a dead pixel was accidentally left in the Chapter 1 final boss arena, all future chapters also have a dead pixel in their respective final boss arenas, with the ones from the fights against Tenna and the Titan even being animated.
- The Sacred Darkness: Chapter 3 elaborates more on the nature of the Dark World and its relation to the Light World. Ralsei is fully aware of the connection between the Darkners and the objects representing them in the Light World because that's what they actually are; they look like ordinary lifeless objects to us because of the presence of light. But as the lights go out and the darkness comes in, the distinction between what's real and what's not becomes blurred, like how in a dark room a chair can look more like a monster or a poster can appear to start moving on its own. Reduce the world to absolute darkness and you can't see anything at all, so it may as well not exist. But what if the world became darker than dark? You get the Dark World, a world of fantasy born from the Dark Fountains emitting darkness purer than normal darkness.
- Santa Clausmas: The version of Christmas that appears in this game seems to be completely secular, with any religious aspects being completely absent. The Holidays, who are big on Christmas, are a religious family, but said religion is later revealed to be a fictional one that just has a Christian aesthetic.
- Save Point: Progress can typically only be saved in the Dark World, via white sparkles that contain some unspecified power. Chapter 4 features a few save points in the Light World due to the plentiful story events that happen there.
- Self-Harm–Induced Superpower: A version of this is present with the Thorn Ring, a powerful weapon equipped by Noelle that causes her to constantly take damage. Noelle can only cast the fatal SnowGrave spell because of the ring's huge TP and magic buffs. If you attempt to equip the ring to Susie, she likens it to a torture device.
- Screw Destiny: Throughout Chapter 4, the party finds scenes of the prophecy as floating glass friezes. Susie is initially impressed at their accuracy to events that they had already experienced and is even pumped at the prospect of her doing something heroic, but Ralsei acts noticeably cagey about them. It turns out that he knows an unrevealed-yet-horrible scene in the prophecy and desperately tries to prevent Susie from reading it because he believes it will occur no matter what, but when she ends up doing so anyway, she defiantly shatters the glass, gashing her hand open in the process.Susie: The hell are you apologizing for? You're worried about THAT!? Seriously!? ...this stupid prophecy? (laughs) Like something like that would happen. I wouldn't let it happen... Kris wouldn't let it happen... And obviously YOU wouldn't let it happen. So... Why wouldn't you laugh? It's just stupid...
[Susie comforts Ralsei with her bloody hand, leaving some on his cheek]
Susie: So stop crying, 'k? Everything's gonna be all right. - Screw This, I'm Outta Here!: Normal enemies will bail out of the battle when their HP reaches zero. This becomes important in Chapter 2's Weird Route, as you have to go out of your way to find a way to kill enemies instead of scaring them away.
- Ship Tease:
- Noelle's crush on Susie transcends "tease" into "all but overt canon". Sadly for her, Susie seems to be Oblivious to Love.
- Berdly develops a crush on Susie after she proved she is a "gamer girl" interested in Dragon Blazers. Noelle is furious, though mostly because of the context of Berdly's claim rather than the fact Berdly has a crush. He also displays some interest in Kris in Chapter 4.
- Whilst Noelle normally expresses that she and Kris are just childhood friends, there are several moments where she expresses she may also be carrying a small torch for Kris too. This gets Played for Horror in the Weird Route, where you force Kris and Noelle into an abusive, codependent relationship by making Kris break Noelle's will to make her completely subservient to them, and by proxy, you. This, among other things, involves saying "We're something else" when asked about Kris and Noelle's relationship, and Spamton refers to her as Kris' side chick. By the time the end of Chapter 4 rolls around, Carol tells Kris that Noelle wants to go with them to the festival — something that is not a good sign.
- Kris's true thoughts are hard to tell since you control them most of the time, but they make it clear that they like Susie more than any of their other friends. They move on their own to defend her from King without your input, they heal more from Susie-flavored tea than anyone else's, and when asked who they'd want to ride the Ferris wheel with, they always make it known that they want to pair up with Susie even if you don't pick her (If you pick Ralsei or Noelle instead, Kris gives their answer in a surprised voice, and if you don't pick anyone, they wordlessly stare at Susie).
- Asgore continuously brings Rudy fresh flowers every day, and Rudy puts on a Gay Bravado act when asked about it. It's a little hard to tell how serious the whole thing is.
- Shoo Out the Clowns:
- Lancer spends most of Chapter 2 in Kris's inventory, and comments on things that happen in the story. During the far darker Weird Route he will fall asleep in Kris's pocket, meaning he will no longer comment on anything. Similarly, Rouxls and Queen's comedic, lighthearted moments are skipped entirely as Rouxls completely petrifies while Queen is wandering around somewhere off-screen.
- The wacky and weird Tenna is abruptly, and literally, disarmed by the Roaring Knight in Chapter 3, and the tone immediately becomes ten times more serious.
- You only get to see your Castle Town recruits at the beginning of Chapter 4. Lancer and Rouxls are completely absent from the Dark Sanctuary, and the Original Starwalker only appears as a stone statue, and a freeze-frame bonus near the end of the chapter. Onion also makes no appearance.
- Shoot the Medic First: Ralsei is almost guaranteed to go down first during harder battles, such as superboss fights, which is a bit of a problem given that he heals the party and that his Pacify spell is the only way to end Jevil's fight non-violently. This is probably just a result of Ralsei's awful health and defenses that makes him statistically the most likely to go down first.
- Shop Fodder:
- The rare Glowshards can be sold for a decent sum of money. Their one practical use is for sparing a Rudinn, but given that Rudinns are among the most basic enemies in the game and exclusive to Chapter 1, it doesn't amount to much. The value they sell for increases with each chapter passed.
- The Dog Dollar only exists to be sold, but gets halved from its base value of 100 D$ per chapter. Not a great prospect when the first one is available in Chapter 2 via a bizarre secret.
- Sigil Spam: The Delta Rune itself appears repeatedly in the Dark World, and the Delta Warriors each have a heart visible on them somewhere. Ralsei has one on his robe from the beginning, Susie's belt buckle is heart-shaped, and and Kris's SOUL manifests as a heart. Elements of the Delta Rune can also be seen in Toriel's house, on the school's front door and on the top of the church's tower.
- Signature Laugh: Like in Undertale, several characters have unique ways of laughing.
- All Undertale characters retain their signature laughs, like Toriel's "Hee hee hee", and Undyne's "Fuhuhu".
- Noelle has "fahaha".
- Jevil has "UEE HEE HEE".
- Spamton has "EAHEAHEAH", which sounds like his voice blips.
- Gerson has "Geh heh heh!"
- Lancer, Susie, King and the Old Man all also have voiced laughs that share the same descending cadence. Lancer's comes first, King's mirrors Lancer's to emphasize their resemblance, Susie's mirrors Lancer's so their laughs can layer over each other, and in turn the Old Man's mirrors Susie's so his laugh can layer with hers.
- Significant Anagram: Explored not only as hints for connections to the previous game, but as a theme.
- "Deltarune" is an anagram of "Undertale", and like an anagram, characters and the plot set-up are rearranged in a different order. On top of that, both names can be turned into the word "unrelated", hinting how Deltarune seems to be a parallel world instead of a continuation of Undertale.
- "Kris" and "Ralsei" are both anagrams of "Frisk" (minus the F) and "Asriel", respectively, who they strongly resemble, but have numerous deviations.
- "Dark" — "Kard"; Playing Card Motifs are present with most major characters from the first Dark World, Card Kingdom.
- "Spamton" is an anagram of "Postman", fitting him being a bot that sends spam emails.
- Silliness Switch: Setting off Starwalker's Event Flag acts as one. After talking to him just once in a secret about halfway through Chapter 1, he becomes a Recurring Extra and appears in every Dark World visited from then on, making frequent remote/blink-and-you'll-miss-it appearances and slightly altering certain scenes in goofy ways due to his appearance and speech, though he tends to stay out of more serious events.
- Sliding Scale of Gameplay and Story Integration: There are multiple examples of this.
- In the battle against the Roaring Knight in Chapter 3, it will notably take reduced damage from attacks. However, this isn't counting the fact that Kris is deliberately coded to deal 50% less damage to it as long as Susie and Ralsei aren't swooned. Moreso, the strategy to defeat them is to have Kris Defend, while Susie uses the TP gained from Kris and dodging the Knight's attacks to spam RudeBuster. This implies that Kris is reluctant to hurt the Knight — not due to fear, but perhaps a different a reason. A certain scene in Chapter 4 confirms these suspicions, making this Foreshadowing to Kris conspiring with the Knight.
- Additionally, if Kris's allies are swooned, their damage to the Knight is doubled. This may imply that Kris doesn't tolerate hurting their friends, even when they were holding back.
- In the battle against the Roaring Knight in Chapter 3, it will notably take reduced damage from attacks. However, this isn't counting the fact that Kris is deliberately coded to deal 50% less damage to it as long as Susie and Ralsei aren't swooned. Moreso, the strategy to defeat them is to have Kris Defend, while Susie uses the TP gained from Kris and dodging the Knight's attacks to spam RudeBuster. This implies that Kris is reluctant to hurt the Knight — not due to fear, but perhaps a different a reason. A certain scene in Chapter 4 confirms these suspicions, making this Foreshadowing to Kris conspiring with the Knight.
- Spiritual Antithesis: To Undertale.
- Undertale was all about player choice and the consequences therein, while Deltarune thus far regularly denies the player the privilege of making any meaningful choices. You're told at the very start explicitly that your choices do not matter, and that's true. It's impossible to kill anyone, there's only a single completely linear narrative that you can't take Off the Rails, and no matter whether you fight the hidden bosses at all or resolve things with violence or mercy, you can't affect anything that happens in any meaningful way. This is subverted in Chapter 2 with the Weird Route though, when it turns out to be a case of Exact Words. Your choices don't matter... but you can push other people into making choices that do drastically change what happens, with gruesome results.
- Both games' take on resolving conflicts with violence are also different. All of your opponents in Undertale are Obliviously Evil at best and Tragic Villains at worst, and can eventually be reasoned with peacefully and even befriended. In fact, doing so is the only way to achieve the Golden Ending. While there still are sympathetic and redeemable anti-villains in Deltarune, there are also several more straightforwardly-evil opponents; King is undeniably, unwaveringly evil, and even if you've been going for a pacifist playthrough, your attempts to settle matters peacefully nearly get the entire party killed, and the "peaceful resolution" is his son overthrowing him and locking him up, with the lesson learned from the encounter being that sometimes a certain level of violence is necessary. Jevil, similarly to King, is irredeemable and craves for nothing but his sadistic entertainment, so the only way to defeat him is to tire him out. Spamton can be redeemed, but he's a lot more in-your-face scummy than anyone in Undertale (besides Flowey), and the Weird Route has him outright cross the
Moral Event Horizon as he becomes The Quisling.
- Spoiled by the Manual: Parodied; the unused assets for the Manual that Ralsei gives you lists the controls for the overworld, menus, text, and (not-actually-in-the-game) cooking, with three of the four buttons corresponding to "butter" and the final one being used for "pulsar cannons."note
- Stat Grinding: Unlike the Character Level system in Undertale, beating up enemies in Chapter 2 onwards will cause your stats to granularly increase.
- Status Effects: The two statuses currently found in the game are Sleep, which works as expected, and Tired, which turns an enemy's name blue and allows them to be spared with Ralsei's Pacify spell without having to turn their name yellow for a normal spare.
- Stealth Sequel: Inverted. At first glance, the game appears to be a sequel to Undertale's True Pacifist ending, seeing as the monsters are living on the surface and Kris, who could easily be mistaken for an older Frisk, is living with Toriel. However, once you get the opportunity to explore Hometown towards the end of Chapter 1, it becomes clear that events don't correlate between the two games and that the cast of Deltarune aren't the same people as their Undertale counterparts.
- Story Branching: Even though the game makes a point of saying your choices don't matter, there are some minor differences in the plot of Chapter 1 where, depending on if you spared or fought everyone, Kris and Susie will be either able to say goodbye to everyone on amicable terms or be chased out of the Dark World by the inhabitants, respectively. Regardless, the beginning of Chapter 2 plays out the same. Chapter 2 gives the player much more choice where, depending on the player's actions, can end with Berdly in a coma. Chapters 3 and 4 have further consequences depending on how pacifistic or violent you are, including a continued Weird Route and the survival of Tenna.
- Story Branch Favoritism: While pacifism/violence plot differences aren't very prominent in Deltarune outside of very specific cases, the Shadow Crystal bosses of Chapters 1 and 2 seem to subtly favor taking one tactic over the other:
- Jevil is typically easier to fight than he is to spare, and sparing him just involves making him tired and casting Pacify as opposed to something more unique. In his post-mercy speech, he states that he will sleep in his cell for another century, ominously warns the heroes, and grants them the Jevilstail, a decent piece of armor with no unique traits. Beat him violently instead, and he commends the heroes' strength, foreshadows the coming of Queen in Chapter 2, and joins the party by transforming into the Devilsknife, which is Susie's strongest weapon as of Chapter 2 and reduces the TP cost of her signature Rude Buster. Beating Jevil violently also doesn't ruin the "pacifist" King cutscene.
- Spamton has a unique spare method in cutting his strings, and arguably the condition he's left in afterwards (falling "dead" onto the ground when cut free vs. exploding in a failed attempt to power up) makes more sense for his post-battle scene and the reaction Kris has while leaving the basement. Not only that, but the cutscene immediately after sparing him also has a unique background and song that aren't present in the violent victory cutscene. His speech afterwards is the same for both, and he turns himself into an item either way, but the mercy-granted Dealmaker glasses (a strong armor that also grants a substantial D$ multiplier) are much less situational than the violence-granted Puppet Scarf (a weapon that massively buffs Ralsei's attack but also cuts his Heal Prayer healing).
- The Forgotten Man seems to favor pacifistic players, as the Weird Route makes his Chapter 2 Egg inaccessible, and being generally violent across Chapter 3 will prevent you from getting its Egg.
- Suck E. Cheese's: The local "Pezza" parlor seems to be this, complete with employees in mascot suits.
- Superboss: Each chapter so far has one extremely powerful optional boss that is characterized by holding a mysterious "Shadow Crystal" and having vague but unsettling connections to the greater narrative of the game or the concept of "freedom". They typically need you to go well out of your way to even find them and are leagues stronger than anything else around their progression point, but will not only drop their Shadow Crystals (which currently serve an unknown purpose), but also an Infinity +1 Sword should you best them. These currently include (in order): Jevil, Spamton NEOnote , the Roaring Knightnote , and the Hammer of Justice.
- Talking Is a Free Action: Downplayed. Talking to enemies through ACTs takes up that character's turn, and the boss fight monologues take several turns to listen to. However, characters are still able to say far more in a turn than they should be, considering that they're in active combat.
- Take That, Audience!:
- A lot of content in the early game pokes fun at common Fandom-Specific Plots, such as Toriel adopting human children post-game. In a more general note, it examines the common fandom wish for there to be a sequel to Undertale by creating a simultaneous Happy Ending Override and a scenario where the main cast doesn't have the same relationships as in the first game, completely averting one of the main reasons that fans wanted to see a sequel.
- The entire Mike segment in Chapter 4's Castle Town is this. Mike, a character conspicuously foreshadowed by Spamton in Chapter 2 and the Sweepstakes ARG, sparked heaps of fan speculation and countless theories prior to the release of Chapters 3 and 4. Throughout Chapter 3, Mike is constantly referenced (especially by Tenna, and is implied to be his producer) but never seen, leaving players even more unsure about his nature. Finally, behind the "Mike" door in Castle Town in Chapter 4, the player can find and fight "Mike" — only, as it turns out, there is no Mike. He appears to be real at first, but it's soon revealed that the identity of Mike is a ruse put on by three Darkners that have decided to share the responsibility of pretending to be him. The punchline is that nobody actually knows who Mike is, not even the three Darkners who have been acting as him. One of the three, a green Pippins, even pulls out a big conspiracy board and goes on a massive rant about how inexplicable Mike's presence (or lack thereof) is, with nobody knowing anything about him yet his existence still being acknowledged by everyone as a fact of life, with no clear origin to it whatsoever. This whole segment pokes fun at the fanbase's mass theorizing about Mike in the lead-up to Chapters 3 and 4, and the three different Mike character designs even pay homage to some of the popular fan-made Mike designs from this time period.
- Taken for Granite: Any Darkner who isn't native to the Dark World they are currently in (barring Castle Town) will gradually turn to stone the longer they stay. And according to Ralsei, The Roaring will turn all Darkners to stone should it come to pass. Chapter 3 seems to imply this can also happen to a Darkner if they lose their purpose. As the chapter goes on, some of the native Darkners start petrifying due to the fact that the TV World is based on the existence of the old cathode TV that served as the basis for the world, and with Toriel planning on throwing it out now that it's obsoleted by newer technology and lack of interest from what remains of the family, the world starts to gradually break down as Tenna's fears of being abandoned peak.
- Technical Pacifist: One way you can play the game, since you cannot actually kill anyone. You can just force your way through every enemy encounter with no impact on the plot, since all of the enemies just run away when out of HP. In Chapter 1, the only differences it makes are that Jevil will reward you with different equipment depending on whether you won violently or nonviolently, and the cutscene with King changes but still has the same outcome. You can also spare the majority of Darkners in the chapter while still fighting certain encountersnote and still get the pacifist ending for the chapter. Starting with Chapter 2, however, beating up an enemy violently (even non-lethally) prevents them from being recruited into Castle Town.
- Tennis Boss: If you use Rude Buster on the Hammer of Justice, he'll swat it back, causing damage to Susie unless you hit it back.
- They Changed It, Now It Sucks!: In-universe, there was fan outcry when the Dragon Blazers games made changes to the source material they were adapting, Lord of the Hammer. Gerson doesn't mind the changes, though, since the book was an adaptation itself of the prophecy, and he's entirely encouraging of further interpretations of it.
- Threaten All to Find One: When Alphys wants to write the assignment on the board, she discovers there is no chalk, and very awkwardly threatens to get everyone in class in trouble if nobody speaks up about the missing chalk. Noelle suggests there might be some chalk in the supply closet. It is then discovered that Susie has eaten all the chalk.
- Too Awesome to Use:
- The Top Cake is a phenomenal item, healing the whole party for 160 HP, more than their maximum HP in Chapter 1, and only Susie's max HP after sealing the Cyber World, 190 HP being high enough to fully benefit from the Top Cake. However, you can only get one by repairing the Broken Cake in Chapter 1, so that usage needs to count. Giving the Top Cake back to Topchef rewards the party with a Spin Cake, which only heals 80 HP but can be replenished infinitely by talking to the chef, even across chapters.
- Post-Chapter 1, the Spin Cake now counts for this. While it got a massive healing buff (it now heals 140 HP for the party), Topchef now resides in Castle Town (instead of the Card Kingdom), which can't be revisited in the middle of a Dark World, restricting it to one use per chapter.
- Defied with the [character] Tea in Chapter 2, which heals a variable amount of HP depending on who uses it. In practice, this exist for observing what the drinker thinks about the drink's namesake, through the Flavor Text and the amount of HP healed. To avoid needing to track or update this in future chapters, the item is downgraded to Rotten Tea if carried into Chapter 3, healing only 10HP.
- Prior to Chapter 4, revival itemsnote are only found in the overworld and not in any shops. Naturally, you'll likely want to save them for the superbosses of the game or bosses. However, in Chapter 4, they can be sometimes stolen from one of the common enemies, meaning you can grind them out if you are willing to spend some time.
- On a related note, the BitterTear, a healing item that restores a party member to max HP regardless of their current health, has only a maximum of 2 in quantity in Chapter 4, only obtainable by using an ACT on a specific miniboss and donating a certain range of money to a donation fountain. Compared to the previous chapter, there aren't really any overly difficult bosses you'd want to save them for (the superboss of the chapter prevents you from using items all together) so you probably wouldn't feel the need to use them.
- In-universe, Noelle has a stockpile of 99 Blaze Potions in her Dragon Blazers III game because she's "saving them". It takes her father's encouragement to convince her to use one.
- Town with a Dark Secret: The Light World town seems perfect and idyllic, like the Golden Ending of Undertale, but there are many unsettling things the player slowly starts to become aware of as they explore the town. To start, someone is opening Dark Fountains that could cause the end of the world, and the "shelter" at the edge of town is some kind of secret facility only a select few townsfolk have the means to enter. Additionally, at an undetermined amount of time in the past, something happened to Dess Holiday that caused her to not be around anymore, though what happened to her is unclear. There was also an incident involving Asgore that seems to have been the catalyst for his and Toriel's relationship to fall apart and resulted in him being fired from the police force. Whatever happened caused much of the town to only speak of Asgore in pitiable hushed tones without wanting to directly discuss exactly what happened, though curiously the Holiday family continues to support him.
- Two-Teacher School: Hometown's school has only two teachers, Alphys for the high school aged kids and Toriel for the elementary schoolers, with the latter doubling as principal. Two other classrooms exist, but one is locked off and the other is not in use (when it's not hosting the Card Kingdom, at least).
- Universal-Adaptor Cast: The game puts the characters from Undertale into a suburban setting far distanced from the Underground. While they lack many elements of their original history and are decidedly unrelated casts, their personalities remain the same with slight alteration to account for their new situations. They also take on similar jobs and/or roles: Royal Guard captain Undyne is now captain of the police force, Alphys is a high school teacher instead of the Royal Scientist, Sans runs a grocery store instead of a hot dog stand, Toriel is a teacher like in Undertale's Pacifist ending, and while Asgore is no king here (he used to be police captain but resigned after an unspecified incident), he still grows flowers.
- The Un-Reveal: At the climax of Chapter 4, the heroes are presented with the final part of the prophecy, setting up the need for an "ultimate tragedy" to finally save the world. Ralsei begs Susie not to look, but before he and Kris can reach her seeing it, she defiantly smashes the visage of the tragedy to pieces. This all happens before Kris, and by extension the player, can also see what was on it.note
- Unreliable Narrator: Downplayed Example. While the description and actions provided about objects, events and actions is always accurate, the same cannot be said for Kris's self. Even though it's gradually pronounced as the story goes on that Kris and the SOUL are two different entities, the narration consistently uses "Kris" and "you" interchangeably when talking about Kris' actions, and assumes the SOUL is Kris's rather than an external entity assuming control of them. That being said, the Weird route slowly starts to avert this the more the SOUL attempts to influence the story and its characters directly.
- Unusually Uninteresting Sight: No one seems to notice how odd it is that their appearances transform whenever they enter the Dark World. Susie does, however, notice how she seemingly gained an ax out of nowhere.
- Vagueness Is Coming: Chapter 4 reveals that the prophecy doesn't have a happy ending, which the three heroes react to in different ways. However, while they know the ending, the player doesn't, as Susie shattered it before it was fully in view of the screen. Susie and Ralsei both refer to it afterwards, but using language that makes it impossible to draw specific conclusions on what it said.
- Version-Exclusive Content:
- Downplayed. An optional area in Chapter 4 features a boss fight and minigames designed with the Nintendo Switch 2's Joy-Con mouse controls in mind, but the other platform releases have the exact same content with said mouse controls are altered to accommodate them. The PC version instead uses microphone controls, while the PlayStation and Regular Switch versions utilise the analog sticks and trigger buttons on their respective controllers.
- The PlayStation version of the game features an achievement system, although all of the achievements are so ludicrously easy to get that you're likely to be encounter them all by playing the game normally and they don't affect gameplay in anyway. However, there's an extremely obscure easter egg for if you somehow managed to complete chapters 1-4 without getting a single achievement, which is nearly impossible given that achievements are permanently saved on your account if you ever get them. The Voice from the beginning of the game expresses its bewilderment that you've made such an achievement (or rather the lack of one) and asks what you are.
- Parodied in Chapter 4 on the Switch version, where inspecting a light switch has some Flavor Text about a red cup doing some so-called "switch exclusive content" by baking "nine tense doughs" on it.
- Violation of Common Sense: The method of being kind to enemies who are trying to kill you is Lampshaded by Susie. And opposed to Undertale, this method is often subverted for each chapter's Arc Villain:
- You can technically win the fight against King without FIGHTing, but either way, Ralsei will be too soft with King and heal him, nearly getting the party killed when King pulls an I Surrender, Suckers!.
- The spare method for Queen's first fight at least makes more sense (loosening Berdly's wire to avoid him getting injured), but once she gets her Humongous Mecha, it's clear that you must fight.
- We Buy Anything: Unlike in Undertale, where you could only sell items to the one character dumb enough to take them, most shopkeepers will accept anything you sell due to money being a much more coveted resource. It's justified in some cases: the Sweet Cap'n Cakes use what you sell as scrap material, while Swatch is forced by Queen to buy trash.
- We Used to Be Friends:
- Most of Spamton's relationships revolve around this, as many characters who can't stand him were once his friends before he went insane. Most notably, Tenna, Chapter 3's Arc Villain, was once his friend and business partner until Spamton ran away after recieving a mysterious phone call. Both have bitter feelings towards the other as a result of that.
- Noelle and Kris used to be close friends as children, but recently grew apart. You can affirm that Kris and Noelle are friends in Chapter 2 to the Addisons.
- We Named the Monkey "Jack": Noelle has a Christmas cactus in her room, which, according to the flavor text, is named "Krismas."
- Wham Line:
- Gives one right in the opening once you've finished creating your "vessel", letting you know what you're in for with this game, especially if you expected this to be a "survey program" or have played Undertale before:
- Alphys' casual "Hey Susie" is one for players of Undertale who spent years wondering about Clam Girl's mysterious neighbor.
- After beating the Chapter 1 Optional Boss and talking with Seam, the shopkeeper will directly quote one of Gaster's lines from the first game:Seam: And my view of this world have become darker, yet darker.
- Throughout Chapters 1 and 2, the game pays no attention to Kris' SOUL, a sharp contrast to how every monster wanted Frisk's SOUL in Undertale. Then comes Spamton, who — for the first time since Undertale — desires Kris' SOUL for himself.Spamton: ALL YOU HAVE TO DO IS SHOW ME YOUR [HeartShapedObject].
- In Chapter 2's Weird Route, interacting with Spamton before you've frozen every enemy you can will net you this chilling callback just so you understand what it is you're doing:Spamton: [X] LEFT.
- And then, still on the Weird Route, when Spamton NEO increases his defence to the point of invincibility, yet another callback drives home the magnitude of what you've just done:Kris called for help... but nobody came.
- At the tail end of Chapter 3, after defeating Tenna, two red slashes appear which cut off his arms. Upon approaching, a mysterious black figure is seen. As the heroes, you do battle. It is then and only then that you realize just what you are dealing with.The Roaring Knight appeared.
- In Chapter 4, when controlling the SOUL in the Weird Route, you have the option to continue or to abandon it. When you pick a certain dialogue option, the tone completely changes.Me
- Wham Shot:
- Chapter 1: Kris removes the SOUL from their body, rejecting the player's control over them. They pull out a knife and flash a red-eyed Slasher Smile at the camera, matching many fandom depictions of Chara.
- Chapter 2: Kris yet again removes their SOUL, turns on the TV, opens the door to their house... and opens up a Dark Fountain in front of a sleeping Toriel and Susie. As darkness covers their house, the TV comes to life with a Slasher Smile.
- Chapter 3:
- When the group manages to leave the green room, they enter a snowy plain and find a tree with a gacha capsule containing Toriel.
- After making amends with Tenna, his arms are suddenly slashed off by the Roaring Knight.
- Chapter 4: The Roaring Knight stabbing several blades into the ground, creating a Dark Fountain while already inside a Dark World, which transforms into a Titan right in front of the heroes, the exact moment of said fountain erupting from the ground being what's depicted on the Title Screen.
- What Measure Is a Non-Human?: Non-Lightner, specifically — while Lightners are treated as ordinary people for all intents and purposes despite being mainly monsters, the Darkners are personifications of toys and games that seem fixated on pleasing Lightners, and their personhood is more ambiguous. In the beginning of Chapter 3, Ralsei blithely states that Darkners are inferior, and that if Kris and Susie ever grow bored of them, then they should just leave them behind and make some "real" friends. Susie is horrified by this, and furiously chews out Ralsei for his self-disregard before they're interrupted by Tenna.
- When All Else Fails, Go Right: The Dark Worlds in Chapters 1-3 start the player off in the west of the world, and have them travel east towards the Dark Fountain. In the Dark Sanctuary, however, the Fountain is immediately to the right, and most of the Dark Sanctuary is spent getting back there after the Knight forces you away. Despite this, you still generally need to move to the right to continue through the Dark World. The Second Sanctuary and the Third Sanctuary return to the standard version of this trope from the previous chapters.
- Wing Shield: In the climatic battle against the Titan, once its health is depleted enough, it covers its face with wings which make even the strongest weapons do almost nothing as it heals.
- Writer Behind the Times: Ralsei's unused manual indicates that the game is intended to take place in The New '20s or some alternate counterpart to it, and there are some topical jokes (albeit for the earlier years of the decade) such as indirect references to COVID-19, Among Us, and Berdly being portrayed as a stereotypical gamer circa 2019. However, the setting overall seems more reminiscent of Toby Fox's own formative years during the Turn of the Millennium, or at most the very early The New '10s. Kris has fond memories of watching movies on the CRT which is still their house's primary television (with only the wealthy Noelle shown to own a flatscreen), Noelle is established by the website and some flavor text in Chapter 4 to have dressed and typed like a scene girl straight out of MySpace, and even the Cyber World seems to be strongly rooted in how the Internet was viewed during the late 90s and early 2000s. Some of this is Lampshaded in game, such as Tenna clearly being behind-the-times and not knowing anything about the Internet and smartphones, but overall, the setting is most reminiscent of the 2000s or earliest 2010s, while characters like Kris and Noelle read more as teenage Millennials circa the late 2000s than the mid-late Gen Z'ers they are presumably meant to be.
- Would Rather Suffer: Noelle's response to the AncientSweet (
impossible to see as of Chapters 1-4, since she's never in the party after the one point the item can be acquired) is that she'd rather eat meat. Bear in mind that she's an herbivore, and every meat item in the game has drastically reduced effectiveness on her. - Yandere:
- Discussed. Berdly mentions the character archetype when talking about Susie after she interrupts and ends the conversation between him and Noelle when Kris and Susie come over in the Normal Route.
- Tenna fits into a non-romantic version of this trope, as he traps the gang in gacha balls and forces them to keep playing the games when they try to leave, since he's terrified of being abandoned.
- Ye Olde Butcherede Englishe: Parodied by Rouxls Kaard's dialogue. He attempts to make himself sound sophisticated and regal by using archaic English, but does so very, very badly. He throws around "-est" and "-eth" endings completely at random (both are verb endings, second and third person respectively), and spells words with unnecessary "e"s and other embellishments. It gets even worse when he tries to add a pirate accent on top of it, with Ralsei quickly convincing him to drop it.
And the places that you know seem like fantasy
There's a light inside your soul that's still shining in the cold
With the truth, the promise in our hearts
Don't forget, I'm with you in the dark
