Chess for Three

Chess for three people utilizing a unique 3-way board. Each player plays against the other two players. The player who checkmates first is the winner. The player who has been checkmated loses and the third player loses as well, no matter whether this player only passively assisted or even consciously or unconsciously helped the checkmating player. Each player must concentrate not only on their own attack and defense, but also on preventing either of the two opponents from checkmating the other.