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 can improvise freely; their choices shape the direction and outcome of the games.

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 is a variety of role-playing game in which players do perform their characters' physical actions, known as live-action roleplaying 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.

Purpose

main: Role-playing game theory

Role playing games are fundamentally different from most other types of games in that they stress social interaction and collaboration, whereas board games, card games, and sports emphasize competition.

Role-playing games are a form of interactive and collaborative storytelling. Like novels or films, role-playing games appeal because they engage the imagination. Interactivity is the crucial difference between role-playing games and traditional fiction. Whereas a viewer of a television show is a passive observer, a player at a role-playing game makes choices that affect the story. Such role-playing games extend an older tradition of storytelling games where a small party of friends collaborate to create a story.

While simple forms of role-playing exist in traditional children's games such as "cops and robbers", "cowboys and Indians" and "playing house", role-playing games add a level of sophistication and persistence to this basic idea. Participants in a role-playing game will generate specific characters and an ongoing plot. A consistent system of rules and a more or less realistic campaign setting in games aids suspension of disbelief. The level of realism in games ranges from just enough internal consistency to set up a believable story or credible challenge up to full-blown simulations of real-world processes.