Bughouse Chess:

Bughouse chess is a popular chess variant played on two chessboards by four players in teams of two. The Normal chess rules apply, except that captured pieces on one board are passed on to the teammate on the other board, who then has the option of putting these pieces on his or her board.

The game is usually played at a fast time control; this, together with the passing and dropping of pieces, can make the game look very confusing and random. The match ends when there is a result on either of the two boards. A game is won when one player gets checkmated, resigns, flags on time or when the player makes an illegal move.