Non-con

Non-con, or Non-consensual is a term used in fanfic to describe a situation in the fic where at least one character is forcing another character (or several of them) to participate in an act that the second party Do Not Want (to do).

This is usually used for smutfic, and the non-con is very often rape.

Depending on the canon or characters involved, non-con can be a charge. This does not stop the fandom, however.