ILLEGAL MOVE
Any move that beaks one of the law of chess. Quite rare at high chess level let us mention the game James Mason-Szymon Winawer, London 1883 where Winnawer played a Bishop’s move with his Knight, at Cambridge Spring 1904 where Karl Schlechter vs. Harry Pillsbury played a illegal move (131) with his King. Later Paul Motwani vs. Murey Chandler in 1990