metagame

A game about games.

The conventions of a gaming community; the characters, weapons, techniques, etc, which are currently considered most viable in multiplayer gameplay, and the best practices for using them.

The exploitation of the rules etc. of some other game, at a higher level than simply playing the game normally; a game outside or peripheral to the actual gameplay.

Of a roleplayer, to make use of knowledge while roleplaying that they learned out of character, which their character does not know; often considered a form of cheating.