Touch-move rule
[3] While j'adoube is internationally understood, a local language equivalent such as "adjusting" is usually acceptable.
A few sites such as the USCF and FIDE online chess websites enforce touch-move by disallowing any other pieces to be played after picking up one.
[4] In the diagram, from a game between future world champion Bobby Fischer and Jan Hein Donner, White had a probably winning advantage; Black had just moved 29...Qg5–f5 and White fell for a swindle.
Had Fischer won the game, he would have tied with Boris Spassky for first place in the 1966 Piatigorsky Cup tournament.
[6] The touch-move rule produced an even more disastrous result for Fischer in his game as Black against Wolfgang Unzicker at Buenos Aires 1960.
[8] In this position in a rapid game between former world champion Anatoly Karpov and Alexander Chernin in Tilburg in 1992,[9] White had just promoted a pawn to a queen on the e8-square.
The arbiter required Karpov to play a legal move with his queen instead (since he touched it), and he selected 54.Qe7+??
But by the time he looked at the position he had already touched his king's bishop, intending 5...Be7 in reply to 5.d4, not noticing that White actually played 5.d3 attacking his knight.
Now compelled to move the bishop, he would lose the knight without compensation, so he resigned immediately.
[clarification needed] J'adoube is internationally recognized by chess players as announcing the intent to make incidental contact with their pieces.
[16] There have been occasions in chess history when a player has uttered j'adoube suspiciously late.
It is possible a late announcement of an adjustment can be used after starting to make a losing move in order to retract it, thus avoiding the touch-move rule.
In the Middle Ages, strict rules were considered necessary because chess was played for stakes.
In the first half of the nineteenth century, rule XIII of the London Chess Club provided: If a player make a false move, i.e., play a Piece or Pawn to any square to which it cannot legally be moved, his adversary has the choice of three penalties; viz., 1st, of compelling him to let the Piece or Pawn remain on the square to which he played it; 2nd, to move correctly to another square; 3rd, to replace the Piece or Pawn and move his King.
[20] While this rule existed, it occasionally led to tragicomedies such as in the 1893 game between Lindemann and Echtermeyer, at Kiel.
"[23][d] The German chess master Siegbert Tarrasch wrote in The Game of Chess (originally published in 1931 as Das Schachspiel) that the former rule requiring a player who made an illegal move to move the king had only been changed a few years earlier.
[25][e] The Fischer random chess variant (also known as Chess960) has custom castling rules wherein the king and the rook end up where they would be in a normal chess game even if they start on different squares because of the randomized start positions.
