Castling *
(* In practice the player will be well advised always to move the K first and then his R when making this move.)
The two Kings and the four Rooks still stand where they stood at the commencement of the game. Let us suppose that hitherto none of these pieces has moved. White, if he has the move, can Castle with Rook h1 by placing it on f1 and simultaneously jumping with King to g1; or he can Castle with Rook a1 by placing it on d1 and jumping with King to c1. Black, if it is his turn to move, can Castle with Rook a8, whereby King and Rook occupy the squares c8, d8 respectively. But he cannot Castle with Rook h8, because the White Queen would attack the Rook after Castling and therefore Castling is illegal.