What does AU mean in roleplay and fanfic?

Updated October 29, 2026

AU stands for alternate universe: familiar characters moved into a different setting or a changed history. A coffee shop AU turns rivals into baristas, a modern AU swaps castles for flats, and a "what if they never met" AU rewrites the past. In AI roleplay you can run an AU with any character by giving them the new setting before your first message and keeping their personality exactly as it is.

Try it now, free, no account neededStart a story with Hadrian VorneThe Dark Lord retired. Now he grows roses, sulks, and needs a ghostwriter for his memoirs. That's you.

Common kinds of AU

The label comes from fanfiction, where writers take characters everyone knows and ask "what if". Some of the most used:

AU	What changes	Example premise
Coffee shop	Everyone works in or around a café	The cold prince is the barista who spells your name wrong on purpose
Modern	Fantasy or historical cast in today's world	A pirate captain runs a harbour bar
Fantasy	Modern cast in a world of magic	The office rival is a court mage
Role swap	Two characters trade places or jobs	The bodyguard becomes the one guarded
Canon divergence	One past event goes differently	The duel ended in a draw, not a death
Soulmate	A rule marks who belongs together	You see colour only after meeting them

The rule that makes an AU work

Change the props, keep the person. An AU is fun because you recognise the character in a strange place: the same dry humour, the same pride, the same way they avoid saying "I missed you". If the personality changes too, you are no longer playing that character, just a stranger with their name.

Ivy Hartwell already runs a late-night café, so a fantasy AU might make her the keeper of a roadside inn at the edge of a haunted wood: still the one who never turns anyone away, still the listener, now with a lantern instead of an espresso machine.

Starting an AU with an AI character

Set it up before the first message, so the greeting doesn't anchor the old setting. On UnsavedAI, choose Start your own way (⋯ menu) and describe the new premise in two or three lines. Ready-to-paste examples:

"Modern AU: Ivy runs a 24-hour laundrette in a rainy city, and I come in at 3 a.m. every Thursday. Same Ivy, new place."
"Role swap AU: I'm the one who owns the café and Ivy is the regular who never says why she can't sleep."
"Canon divergence: we met five years ago instead of tonight, and it ended badly. She still recognises me."

With your own characters, the same brief goes into the scenario field at /chat/custom.

Stopping the old canon from creeping back

The character card still describes the original world, and the model reads it every reply, so details leak: a castle turns up in your modern flat, or the barista mentions their sword. Two fixes keep an AU steady. Put one line in Story memory (⋯ menu, signed in), such as "- AU: modern Lisbon; no magic, no palace; the prince works at a museum." And Edit out the first leak as soon as it appears, because a leaked detail left in the chat invites more.

Characters who already live in an AU

Some house characters are built on an alternate-universe twist. Hadrian Vorne is a Dark Lord who retired and now grows roses and sulks. Tilly Brightwater is a game's innkeeper who woke up. Director Rafael Ortega polices branches of history, and you arrive from a timeline that shouldn't exist. For more of that last kind, see time travel roleplay.