Definition of roleplaying game:
(n) :
(video games) A type of computer game where the player takes the role of a character or party, normally lacking tests of physical skill and including more story-telling and narrative aspects than traditional action games.
(n) :
(games) A type of game where one or more players assume the roles of characters (usually one each) to interact with a fictional world either defined by themselves or through the moderation of a neutral judge (usually referred to as the game master).