Four-player chess variant played on two connected normal chessboards.
The game is played in two teams: Yellow and Red play against Green and Blue. Move order: Yellow, Green, Red, Blue.
The teams win and lose together. The game ends at the first checkmate, and the team whose member delivered the mate wins. The teammates cannot capture each other's pieces.
Details: Four-player chess.
Uray M. János, 2013 – and independently J. L. Naylor and E. Ower, 1925.