A role-playing game (RPG; often roleplaying game) is a game in which the participants assume the roles of fictional characters. Participants determine the actions of their characters based on their characterization, and the actions succeed or fail according to a formal system of rules and guidelines. Within the rules, players have the freedom to improvise; their choices shape the direction and outcome of the game.
Most role-playing games are conducted like radio drama: only the spoken component is acted. One player, the game master (GM), creates a setting in which the other players play the role of a single character. The GM describes the game world and its inhabitants; the other players describe the intended actions of their characters, and the GM describes the outcomes. Some outcomes are determined by the game system, and some are chosen by the GM. There are a variety of role-playing games in which players do perform their characters' physical actions, known as live action role-playing games (LARP).
A genre of video game is also referred to as role-playing games. Although these games do not involve the playing of roles, they take their name from the settings and game mechanics which they inherit from early role-playing games. Due to the popularity of video games, the terms "role-playing game" and "RPG" have both to some degree been co-opted by the video gaming industry; as a result, games in which players play the roles of characters are sometimes referred to as "pen and paper" or "tabletop" role-playing games, though neither pen and paper nor a table are strictly necessary.