An Original Character Tournament (OCT)
An Original Character League (OCL)

When people make character(s) and have them battle or interact with other peoples characters, in any form of artistic medium.

An OCT is a completive form of this done in brackets

An OCL is a more freeform way of doing this where an artist ask another artist if they would like to have their OC's interact or battle. (its kind of like a pokemon battle)

If you got any more questions do ask.

okie dokie lokie