A school of role-playing games in which the person running the game (often called a game master or dungeon master) creates a puzzle, problem or quest in an imaginary setting which the players then have to investigate, using their characters' abilities, skills and powers, as well as the players' own innate intelligence. A skilled gamemaster can make these games intriguing and thought-provoking, and encourage good role-playing at the same time. At their worst, these games are difficult and tedious.