Bughouse chess

Bughouse chess is a chess variant for four players who form two teams of two and play on two chessboards at the same time. Ordinary chess rules apply, with one addition: a piece captured on one board is passed to the capturing player's teammate on the other board, who may then choose to put that piece onto their own board. The game is usually played at a fast time control, and together with the passing and dropping of pieces this can make play look chaotic to a casual onlooker, which explains the name, since bughouse is slang for a mental hospital. It is also called exchange chess, tandem chess, transfer chess, double bughouse, doubles chess, cross chess, swap chess, Siamese chess, or simply bughouse, bugsy or bug. The name Siamese chess should not be confused with Thai chess. Dedicated bughouse tournaments are organized each year at national and international level.