The game of Scotan chess was first thought of by an anonymous monk who didn't know how to play the original chess so had devised a version of chess that was also used by Rock, paper, scissors. The concept is that in Scotan chess, certain pieces can move different ways and some are restricted. But if players encounter a piece on a square and the current player's piece is within their Zone of Reach, then the opponent can be challenged to a match of Rock, paper, scissors. But it's not just 1 match of RPS, the number of matches is dependent upon what piece is used to challenge the opponent.