Glitches
There are many glitches in Deltarune, ranging from being game-breaking, causing minor visual, audio, or cause incorrect text. Some of these are Chapter-exclusive, while others continue across multiple Chapters.
In Chapters 1 & 2, Ralsei’s attack box doesn’t light up when attacking, this due to a bug instead of pressbuffer[1], pressbuffer[2] and pressbuffer[3] being set to 5, the game instead sets, press buffer[0], pressbuffer[1] and pressbuffer[2] to 5.
When any party member is on 2HP, the party cannot be killed by overworld hazards.
If two or party members use a Glowshard in the same turn against a Rudinn, The GLOWSHARD disappeared!" text will appear, though both the Glowshard and the item in the second or third (depending on if 2 or 3 party members used the Glowshard) inventory slot will disappear. This glitch can be used to remove the Manual without it being considered tossed.
In the original Chapter 1 demo, hacking to give Susie the Wood Blade prior to the battle with Dummy would prompt the text, "... You have a SWORD!?" As of the Chapter 1 & 2 Demo, this text is inaccessible even with save editing due to a code typo, in which wmessage2temp was misspelled as wmessage2tempt.
Versus Tasque Manager, performing the individual ACTs for Kris, Susie, and Ralsei causes their respective wan sprites to only appear as an afterimage due to scr_act_charsprite_end immediately setting the party to their idle poses.[1]
On the Switch version of Deltarune, in the room right before Berdly’s first fight in Cyber Field, moving along the left wall of the door to enter the roller coaster will cause Kris to clip out of bounds.
If Kris interacts with K_K at the point where the shortcut door in Cyber Field is, and are aligned correctly with Kris as close to the door as possible, and choose to buy 400 bagels, once the dialogue appears, “You just couldn’t hold that many”, if the player presses up and interacts with shortcut door, it will cause the flavor text from the empty door to start, however, Kris can still move. If K_K is interacted with again, and the [CONFIRM] button is pressed, but not the [MENU] button that skips it automatically, it will cause the door warp selection dialogue to appear. If any of the locations are chose without being in a location where an interaction with K_K or the empty door will start, Kris will warp to that location. Otherwise, it will trigger a Choicer Overflow. This glitch notably can cause a lot of side effects and other glitches.
Glitches caused by the Bagel Overflow.
If the room is exited before the music comes back up after selecting to buy 400 bagels, then the music will stop playing until the music is reset. Sound effects still play.
If the Bagel Overflow is used to activate the Shortcut door to Queen’s Mansion and the Dining hall is entered the cutscene will play out wrong due to entering it from an unintended screen transition.
Normally when Kris goes to the bathroom in the Dreemur Residence to wash their hands, the door is unable to be opened, but by pressing the Home button on consoles, the door becomes openable again, allowing for Kris to leave the house, to either go back to Hometown or enter Castle Town again.
If White Cloak is hit by HERO_SWORD in the room she’s found, and the room is exited at the same time, it will cause her color palette to be inverted for the rest of the Ice Palace, until she’s used up.
Due to a programming oversight, talking to the third curtain NPC will prevent Miss Mizzle from noticing Kris has flirted with the Watercooler nearby in her fight, as the flag used to check is also used by this particular curtain NPC. Miss Mizzle's battle logic does not account for the flag's value changing after if talking to this curtain NPC after flirting, causing this error.
Owning the BlueRibbon prevents the BlackShard from spawning at the cliff in Castle Town. This is a bug due to the two items sharing the same ID number, which tricks the game into thinking that the player obtained the Black Shard.
On PC only, every Light World item cannot be dropped, this is because the code that checks whether a Light World item is a weapon or not will always at least return the ID for the Pencil, causing all items to be prevented from being dropped in Chapter 4.
| Name | Effects | Chapter | Image (optional) |
|---|---|---|---|
| Kris’s window placement | The window in Kris’s room is moved up by one pixel from Chapter 1 to Chapter 2 onwards. | 2 | |
| Invisible Queen | After defeating Queen through ACTing, there is a rare chance that she turns invisible until her escape. | 2 |  |
- ↑ gml_Object_obj_tasque_manager_enemy_Step_0 script, lines 285–287, Chapter 2
