Player versus player, or PvP, is competitive interaction within a game between two live participants. This is in contrast to games where players compete against computer controlled opponent, which is similarly referred to as Player versus environment (PvE) or player versus monster (PvM). PvP is a type of combat in MMORPGs, MUDs and other computer role-playing games (CRPGs), pitting one player's 'skill' against another's.

PvP can be broadly used to describe any game, or aspect of a game, where players compete against each other. This can include entire gaming genres, such as first-person shooters or real-time strategy games, or can be limited to an optional part of an otherwise PvE game. In computer role-playing games, PvP is often called player killing or PKing, especially in cases where the combat was not consensual. The term PvP, and to a lesser extent PKing, has also been adopted in discussions about traditional role-playing games and live-action gaming, with approximately the same meaning.