Provided is a game device for executing a game in which a user participates and another user is allowed to join the game in mid-game. The game device obtains stored data from a unit for storing data that indicates a situation of the game being executed and that is updated with progress of the game. A situation determining unit determines whether or not the situation of the game being executed satisfies a given condition. A mid-game joining restricting unit keeps a user who has not joined the game being executed from joining the game in mid-game, based on a result of the determination of the situation determining unit.