Been having a lot of thoughts about AUs this week. An AU is a piece of fanfic taking characters and shifting them in some way from their canon selves, or it's literally any episode of COMMUNITY.

I've been trying to find a way to categorize them, and it's not working so well. But you have your alt. history AUs, like @Colubrina_'s "The Green Girl," which is a borderline canon-compliant "what if Hermione had been sorted Slytherin?" One change, big consequences.

And then you have your genuinely A AUs, the fabled "everyone works in a coffee shop" or "everyone is a werewolf," that are more about finding the things necessary for a character to be recognizably themselves.

Crossover AUs, like Sailor Ptah's incredible Welcome to Night Vale/His Dark Materials "Republic of Heaven Community Radio" series, are sometimes better than their source material (true of all fanfic, really...).

I'm currently reading an in-name-only AU. Non-magical, soft erotica, clearly written when 50 SHADES OF GREY was a big thing. It's well-done and fun, but it bears about as much resemblance to the source material as I do to a moose. Both have hair.