Question for literary types who read my blog

I've been casting about trying to remember if there's a term for a certain type of fiction, and was hoping one of y'all could help let me know if there's an official term for it. In short, fiction that could conceivably happen, presuming the characters, organization, etc existed.

CLARIFICATION: I want an official term, used and accepted by specialists in literature. Not speculation, not coming up with your own terms. I can do THAT myself just fine.

( Rambling around behind cut )