Undertale Yellow Wiki

Before the seventh... There was another.

- Official Trailer

Undertale Yellow (stylized as UNDERTALE YELLOW) is a turn-based role-playing game based on Toby Fox's Undertale. The project is led by Master Sword and is developed on GameMaker: Studio.

Greenlit by Toby, it is notable for having famous faces behind the game's soundtrack, such as NoteBlock, MyNewSoundtrack, and Master Sword himself. It is currently in development, with the first version of the demo having been released on November 30th, 2016.


Undertale Yellow's battle menu is similar to Undertale's, although the LOVE system focuses on Defense rather than Health.

Undertale Yellow reuses some of the vanilla game's mechanics with turn-based rounds and a Fight-Spare system. However, the developers have stated that the game will deviate from Undertale in a few aspects.

One deviation from Undertale, gameplay-wise, is the fight mechanics used. Instead of Undertale's stretched oval attack board, Undertale Yellow uses a circular target attack board.

Undertale Yellow's new fight mechanic.

There is a white ring that starts from the outside of the target and quickly moves inward while getting smaller. The closer the circle gets to the middle, the more powerful the attack will be. If the circle gets to the very middle without being stopped, it will be counted as a miss.

Despite the fight mechanic change, the dodging system will stay the same as the original Undertale. Initially, the game's dodging system was going to be based on the Mettaton EX fight, but the ideas were later scrapped.

The Underground has been expanded, with the player being able to explore previously unseen areas throughout the game's locations. The main addition so far is the inclusion of the Dark Ruins, a significantly darker and more damaged layer of the Ruins, containing another exit to Snowdin.

The game also retain's the witty dialogue and narration of the original Undertale, as seen throughout the Dark Ruins and Flowey's commentary. It also features the system of three routes, with the player being able to embark on the Neutral, Pacifist and/or Genocide routes.

Main Story

The game's main plot is the same as that of Undertale, with the war between Humans and Monsters, and the latter being sealed inside the Underground via a magic barrier. However, it follows the journey of the seventh human that falls into the Underground. This human is a young child named Clover.

An ambiguous amount of years after the war, multiple humans have been rumored to disappear after heading toward Mount Ebott. With a Missing Poster in hand, Clover heads toward the mountain to investigate, and deliberately jumps into the Underground. There, they team up with Flowey and explore the Underground, with Flowey offering to Save for Clover.

Because Flowey is present in the game, it is possible that Undertale Yellow takes place just after the experiments that led to the creation of the Amalgamates. This implies Alphys will make a reappearance.

There is also a timeline for the game which has several events that occur in between the monsters being sealed underground and Clover going into the underground, most of them are likely the other humans falling but some might be new events that could effect the game's plot.


Undertale Yellow started development on the 4th of February, 2016 after Toby Fox greenlit the game's creation. On the 28th of March, the game got itself a GameJolt page. It would not gain much attention, however, until the 30th of April when the official trailer for the game was released.

Since then, the game's official Twitter account has been the main place to reveal new information about the game. Months later, on the 30th of November, the first demo for the game was finally released to the public, which was met with overwhelmingly positive reviews.

The game has also gotten lots of progress reports since the demo's release and also lots of teasers for different areas of the game. There is no determined release date for the game yet, however what's known is that the neutral final boss has gotten quite a good amount of work done and it is said to be one of the most ambitious parts of the game, the game will very likely see a release sometime in 2022 perhaps towards the latter half.

Development Team


  • MasterSwordRemix (Director of the game)
  • MyNewSoundtrack
  • NoteBlock


  • SpartanScooter
  • MysteryRacer


  • Pippy V.


  • AWildDaydreamer
  • Fireburn02
  • Gaziter
  • Emmalume
  • TheAllKnowingNoodle

Concept Art

  • ThisIsntEli
  • Litvac
  • Grey Duovis
  • Still Liam
  • Fireburn02
  • TheAllKnowingNoodle


  • Oranebeast
  • LockRikard

Video gallery


  • When Master Sword was asked about how he got the idea for the game, he said that he simply thought of the game and several ideas for it one night, and the next day hurried to find enough people to make it a reality.
  • Master Sword has stated no young versions of the main characters from Undertale will appear. He also stated that W. D. Gaster, Sans, Papyrus, and Undyne will not make an appearance in the game.