RvR

Short for Realm vs. Realm, RvR is combat in an MMORPG (Massively-Multiplayer Online Role-Playing Game) where players compete against opponents of a similar level to take objectives or defend their base, flag, or position. Often taking control of one or more objectives give all participating players a buff, experience, or other additional character attributes.

RvR is similar to the more commonly-known PvP (Player vs. Player) combat except that it tends to involve many more players.

Game terms, PvP, TLA