An alternate universe, or AU, is a universe that is similar to but not the same as any other given universe--typically because of a few small changes. Any canon universe can have AUs.
AUs are typically invoked when canon relationships have never been extablished, when significant events don't happen, or don't happen the same way, or where something completely inexplicable has happened. Common types of AUs include:
- All the characters are in high school (extremely common in South Park fanfiction)
- Replacing the setting and/or cast of one series with that of another (a type of crossover).
- The canon characters falling into another world.
- "What If" stories that make some change to canon and explore the logical result:
- Changing the cast by killing off a character, bringing one back to life or changing an event so they never died, and then writing the story in a different direction.
- Changing events and following the original canon characters through a new history. For example, the fic might ask, "What if Kenny stayed dead?" and then follow the boys lives to show how their history plays out differently. The change is often small, but the effects tend to snowball.
- Changing events to put different characters in the spotlight--usually OCs or minor characters, but can be major characters in different roles from the ones they usually occupy. For example, a fic that asked, "What if Kyle's family had never moved to South Park?" might have the other boys never really becoming friends, changing the focus of South Park to some other group of characters.
- Fics that take place in the past or future may sometimes be considered AU.
When writing a fanfiction, it is always a good idea to have a good hard think about whether your story is AU or not. Claiming it isn't when it clearly is may result in readers not taking you seriously. On the other hand, labeling your fic AU does not excuse bad writing or poor characterization, so it isn't a free pass to do whatever you want, either. Choose wisely.
Signs You're Doing It Right Edit
- One basic change is made; the rest of the canon stays intact and reacts the way it usually would.
- The characters react plausibly to their new situation.
- If a character's personality is changed, a logical reason exists.
Signs You're Doing It Wrong Edit
- The existence of one or more Mary Sues.
- Multiple, random changes that have no common theme.
- Changes that seem to be contrived for the express purpose of realizing a favorite pairing.
- Only one result of a change is explored--all the others are ignored, even when there should be widespread effects.
- Characters share only their names with their canon counterparts.