Bughouse chess and random to the casual onlooker; hence the name bughouse, which is slang for mental hospital. The game is traditionally played as a diversion from regular chess both over the board and online. Yearly, several dedicated bughouse tournaments are organised on a national and an international level. Bughouse is a chess variant played on two chessboards by four players in teams of two. Each team member faces one opponent of the other team. Partners sit next to each other and one player has black, while the other has white. Each player plays the opponent as in a standard chess game,
Janus Chess checkmate cannot be . Due to the extra pieces, each player starts the game with considerably more " power" compared to standard chess; however, the game has only a slightly higher material "power density", since there is more room for players to maneuver pieces because of the larger board (10×8 = 80 squares). Due to the different board and pieces, players are unable to use normal chess opening theory, and chess tablebases have limited value in the endgame. Janus Chess has been popular in Europe with regular tournaments drawing strong players. Several chess grandmasters have played this game including Viktor