UNDERTALE / ALTERNATE UNIVERSES
An AU changes the premise. It does not change canon.
Undertale alternate universes are fan-made settings, role swaps, timeline branches, and tonal reinterpretations. Their variety is the point: an AU can inspire many versions without becoming official Undertale lore.
Take the independent Soul Virtues testThe short definition
AU means “alternate universe.” In Undertale fandom, it describes a fan-created premise that changes some combination of the setting, roles, designs, timeline, tone, or story rules.
An AU is not a route, sequel, or secret canon timeline unless an official work explicitly says so. Most Undertale AUs are independent fan works built by one creator or a community of later interpreters.
Common ways an Undertale AU changes the source
| AU pattern | What changes | Familiar example |
|---|---|---|
| Role swap | Characters exchange narrative functions, relationships, or encounter roles. | Underswap and its many later interpretations. |
| Tone reimagining | The cast and Underground are reframed through a harsher, darker, or more hostile tone. | Underfell. |
| Setting transformation | The story keeps recognizable relationships while moving into a new visual world or environment. | Outertale’s space setting. |
| Canon divergence | A familiar event changes and the new timeline follows the consequences. | Long-form projects such as Inverted Fate. |
| Crossover or multiverse | Several AUs, timelines, or fan interpretations interact. | A broad fandom category rather than one canon system. |
Why one AU name can have several versions
Some early AUs were shared through short posts, reference sheets, asks, or art accounts rather than a finished comic or game. When original material stopped updating or became difficult to find, later fans developed their own versions.
That means a character design, personality, or relationship associated with an AU name may come from a later interpretation. Careful guides credit a specific creator or version instead of presenting one fandom consensus as definitive.
AU, fangame, and fanon are related but different
- An AU is the alternate premise or universe.
- A fangame is a playable fan-made project; it may use canon, an AU, or an original continuation.
- Fanon is an interpretation widely repeated by fans without being established by the original game.
For playable projects, continue to the Undertale fangame discovery guide.
How SoulVirtues.com handles AU material
This site may use an AU as cultural context, but it does not assign official Soul Virtues to fan characters or merge AU lore into the assessment’s scoring method. Creator credit, version boundaries, and an explicit fan-made label are required.
The assessment remains based on the user’s own answers, not resemblance to a canon or AU character.
Sources and further reading
Fanlore’s Undertale overview documents major forms of fandom activity. Community references include pages for Underfell, Underswap, and Outertale. Inverted Fate’s creator site is an example of a specific long-form AU source.
Community wikis can help locate terminology, but creator-controlled pages take priority when describing a specific AU version.
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