~from WikipediaAn alternative universe (also known as AU, alternative timeline, alternate timeline, alternative reality, or alternate reality) is a setting for a work of fan fiction that departs from the canon of the fictional universe that the fanwork is based on. For example, an AU fanfic might imagine what would have taken place if the plot events of the source material had unfolded differently, or it might transpose the characters from the original work into a different setting to explore their lives and relationships in a different narrative context. Unlike typical fan fiction, which generally remains within the boundaries of the canon set out by the source material, alternative universe fanfic writers explore the possibilities of pivotal changes made to characters' history, motivations, or environment, often combining material from multiple sources for inspiration.
AU stories are also sometimes used in official, though typically non-canonical, storylines, written by the creators of the original canon material.
I was thinking about putting this thread in rp discussion forum but then thought it would be more interesting to explore broader application, not just rp, but also fanfiction, alternative history, comics multiverse... Everything that can somehow fall under alternative universe concept.
I like alternative timeline and canon divergent AU in fanfiction/rp a lot. Where you somewhat follow canon events until certain point and then something happens that brings the story into a totally different direction. Where things that happened in canon can still happen but under different circumstances and would lead to different results.
What are the most interesting types of AU for you?