Deltarune: Secrets and details you might have missed

Deltarune, the official follow-up to Undertale, has a ton of secrets. Just like its predecessor, you can find a ton of easter eggs in everything from the dialogue, to your equipment, to the actual game code. Some of this stuff is just a neat distraction, while some alludes to deeper and darker plot points that may be revealed in the full game.

Here are some secrets that you may have missed in your Deltarune playthrough.

WARNING!!! Spoilers ahead.

Naming your character

Just like Undertale, Deltarune has a number of easter eggs in the “name your character” screen. By giving your character the same name as any of the characters in the game, the game will comment on the coincidence. By naming your character the same as your player, the game will comment on how they are “one and the same.” Naming your character Chara or Frisk will cause the game to say “how interesting. You are about to meet someone very wonderful.” However, the biggest easter egg happens when you name your character “gaster.” Doing so will make the game restart.

Going to sleep

If you played through the game once, you can actually skip the prologue by examining your bed right after you wake up. By choosing to sleep again you will end up in the first scene in the dark world without having to go to school.

The wrist protector

If you manage to get to the dark world in under eight minutes, whether by playing quickly or by going to sleep, you will find an item called the wrist protector. This allows you to hold C in order to skip text. It takes up no space in your inventory, so it’s useful for speedruns. It’s also called a wrist protector because it is protecting your, the player’s, wrist by lessening the need to mash on your keyboard to forward text.

Deltarune’s version number

If you open up the properties for Deltarune’s executable, you will see that it is version In Undertale, Gaster’s stats were supposedly all 666 in a scrapped combat encounter.

The cell phone

Attempting to call anyone with the cell phone in the dark world plays the “entry #17” sound file from Undertale, an entry made by Gaster.

The red door

The creepy sound file that plays when examining the strange red door at the end of the game is also the “entry #17” sound file, slowed down.

Gaster look-alikes

You promay have noticed that Rouxls Kaard is designed to be something of a foppish Gaster look alike. However, you may also notice that Seam, the Seap owner, is also designed like Gaster, with his button eye taking the place of Gaster’s open eye.

Gaster’s follower

In the library at the end of the game, the monster that blocks access to the rest of the books looks similar to one of Gaster’s followers in Undertale.

Gaster’s theme

Much of the game’s soundtrack follows a leitmotif based on Gaster’s theme from Undertale. Nine tracks have been confirmed to follow this pattern, including Another Him, Darkness Falls, Card Castle, Scarlet Forest, Gallery, The Circus, Ruruskaado, and The Holy.

Credit to MediaMotifs from YouTube for first noticing the Gaster's Theme LeitMotif.

Rouxls Kaard

Enemies in Deltarune are themed after game pieces, with main antagonists themed after playing cards. Rouxls Kaard is a pun on “rules card” the card in a deck that tells you how to play poker that you remove before using it.

Hidden code messages

Opening up the files of the game and examining the file that stores all the dialogue gives you this strange line of unused dialogue that appears to be a call for help. It’s strangely stored under “The Return” which is what the game is called after you defeat the final boss and return to town in the end-game.

The title bar

Over the course of the game, the programs title bar will change. As said before, it turns into “The Return” in the endgame, it also turns into “The Dark” in the dark world and “The Death” if you die.


At the end of the game, checking the gravestones in town will reference monsters that were part of the amalgams in Alphys’ hidden lab in Undertale. There is also a gravestone for Gerson, one of the shop owners in Undertale.

The purple guy

The mascots in town at the end of the game reference a “purple guy” which may be a reference to Five Nights at Freddy’s, another indie game that rose to popularity around the time of Undertale.


Everyman, one of the amalgams’ attacks in Undertale, shows up randomly in attack patterns in the secret Jevil boss fight. He also shows up as graffiti in an alleyway at the end of the game.

Susie’s belt buckle

After Susie learns compassion and officially joins the party, her belt buckle turns from an X into a heart.

You can’t die

In the one on one Susie vs. Lancer fight, it’s actually impossible to die. You can run into Lancer’s projectiles all you want, but eventually they will auto-miss, and you cannot damage yourself enough to die before this happens.


In Undertale, all portraits were done in monochrome black and white. This still holds true for anyone from the “real” world in Deltarune, while anyone from the dark world has a full color portrait. Notably, the only enemy who had a full color battle portrait in Undertale was Flowey/Asriel.

The doors

The teleportation doors that let you fast travel use the same graphics as the door to Sans’ room in Undertale, suggesting that this might be how he warped around the world so fast.

Locked in a cage

In the final scene of the game, where Kris rips out his soul and shoves it in a cage, you can control the soul inside the cage. This suggests that the soul Kris ripped out was your soul, and that you were essentially puppeting Kris around during the events of Deltarune.

Is that a new haircut?

The game has a recurring theme of eyes. Susie’s eyes are hidden when she acts as a bully, but are revealed in her character portrait after she learns to care and join the party. Interestingly enough, Kris’s eyes are always hidden.

Become a bed inspector

If you check all the beds in the card castle, your title will become a “lvl 1 bed inspector.”

Almost but not quite

When Deltarune starts up, it seems to bait you into thinking it’s an Undertale sequel. However, when wandering around the town at the end of the game it’s clear that it’s an alternate universe of sorts. However, there are tiny things that you can catch that point toward this fact before the endgame, such as Undyne having both of her eyes.

The strange saga of the tree and the egg

After the gauntlet of birds firing bullets at you, you can occasionally find a secret room by going back and forth over the right side screen transition. This will “wrong warp” you into an area containing a lone tree. Searching behind the tree will find you a man who will give you an egg. In the endgame, you can put the egg in Asgore’s fridge and it will sometimes double itself. Attempting to interact with the egg will get you a “what egg?” prompt which seems to be a reference to the “what pumpkin” joke from Homestuck and Problem Sleuth.

Secret item usages

Using the glowshard in battle will let Ralsei absorb it. Using the manual in battle will bore enemies to sleep and let Ralsei pacify them. Attempting to toss the manual will cause Ralsei to pick it up and put it back in your inventory. Tossing it again will destroy it and hurt Ralsei’s feelings.

Restoring the cake

Taking the broken cake to the smith will get you a Top Cake, the best recovery item in the game. However, if you bring the Top Cake back to the baker, he will give you infinite Split Cakes, which heal the party half as much as the Top Cake, but you can get an infinite amount of.

The lake monster

Standing on the circle next to the lake in the endgame will prompt a cameo from Onion-san.

The toilet

In the beginning of the game, flushing the toilet multiple times will prompt dialogue from Toriel. Continuing to flush will get you more dialogue.

Dog stats

Scrolling through the status screen will sometimes replace one of your stats with “dog” and a picture of the annoying dog.

Swords, pencils, and junk

Deltarune strongly suggests that it is an “all just a dream” narrative. Kris’s normal sword is described as a “wooden blade with a carbon reinforced core” and in the real world he is equipped with a pencil. If you equip Kris with a spooky sword they will be equipped with a Halloween pencil in the real world. Finally, Kris’s ball of accumulated junk is largely alluded to be all of the items you collected on your journey. Attempting to throw it away will make Kris’s hands shake, like they don’t want to give it up.

That’s all the secrets we have for you today. If you found any we missed, feel free to post them in the comments!