The Rules of Cypher Chess

​

VII. Check, Mate, Flipping and other rules.

​

a. The King is put into check by major pieces, including the op-posing King and Spy, from Court or Border squares and by pawns in the entire Field-Border region. To prevent or halt check, a player can use pieces to block check; how-ever, as stated above, the Spy can-not block check within the Field or Border; it can only block flip-ping within Court. 

​

b. If a player checks the opponent 4 consecutive times without scor-ing mate, the game ends in a draw. This is the "4-Check Rule."

​

c. Once a King steps into Court, it can only be attacked by the Spy, which amounts to flipping-- a game-ending move.