Undertale AU Wiki
Welcome to the biggest encyclopedia on Undertale and Deltarune AUs.

There are currently 555 articles, 2,143 files, and 82 active users on the site!

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About Undertale AUs
Undertale Alternate Universes, or "AUs", are alterations to the story, world, and/or characters of Undertale, be it crossovers, changes in aesthetic, or role-swaps.

"AU" is an umbrella term that includes "ATs".

Featured Article
Inverted Fate
Inverted Fate - Characters.png

Inverted Fate is an Undertale AU taking place after a failed True Pacifist run. Asriel won the final battle and started to reset time, but lost control of his powers, resulting in the six main characters or "lost souls" swapping places but not personalities. This ends up creating a very different Underground.(more...)

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Latest Blogs
AstralPastels AstralPastels 4 days ago


- Introduction

Taigatale is an Undertale AU d…

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MTT AU maker MTT AU maker 5 days ago

Undertale Art book

These are ym drawings of Undertale enjoy


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