Touch-move rule the player touches his rook at the same time as touching the king, he must castle with that rook if it is legal to do so. If the player completes a two-square king move without touching a rook, the player must move the correct rook accordingly if castling on that side is legal. Otherwise, the move must be withdrawn and another king move made. When a pawn is moved to its eighth , once the player takes his hand off the pawn, a different move of the pawn can no longer be substituted. However, the move is not complete until
Fifty-move rule discovered that certain endgame positions are winnable but require more than 50 moves (without a capture or a pawn move). The rule was therefore changed to allow certain exceptions in which 100 moves were allowed with particular material combinations. However, winnable positions that required even more moves were later discovered, and in 1992, FIDE abolished all such exceptions and reinstated the strict 50-move rule. The relevant part of the official FIDE laws of chess is rule 9.3: A claim does not have to be made at the first opportunity – it can be made any time when there have been