Touch-move rule in chess

In over-the-board chess, if you deliberately touch one of your own pieces on your move, you must move it if it has a legal move. If you deliberately touch an opponent's piece, you must capture it if a legal capture exists.

The touch-move rule means you should think before touching a piece in tournament chess. If you deliberately touch a movable piece, you are committed to moving that piece.

Touch-move is a real rule in formal over-the-board chess. It is part of tournament practice and can be enforced by an arbiter.

The touch-move rule usually does not apply in standard online chess. Online play normally commits the move when you release the piece or complete the click, although some special over-the-board simulation modes can enforce touch-move.

Online chess does not usually use touch-move because the interface lets you pick up a piece digitally before the move is completed. In most online games, the move becomes final only when you release the piece or confirm the destination square.

A mouse slip is an online error where a piece is dropped on the wrong square. A mouse slip is usually final in rated games even though touch-move itself is not normally used online.

J'adoube means I adjust. It tells your opponent that you are only straightening a piece on its square and do not intend to move it.

You should say adjust or j'adoube before touching the piece. If you touch first and explain later, you risk being held to the touch-move rule.

You can touch a piece without moving it only when the contact is clearly accidental or when you say adjust or j'adoube before touching it to straighten the piece on its square.

Saying adjust after you have already touched the piece may be too late. The safe habit is to announce adjust or j'adoube before your hand reaches the piece.

Accidental contact does not normally count as touch-move. The rule is about deliberate touch with the intention of moving or capturing.

If the touched piece has no legal move, touch-move does not force an impossible move. You may then make any legal move with another piece.

If you deliberately touch an opponent's piece on your move, you must capture it if a legal capture is available. If no legal capture exists, you are not forced to make an illegal capture.

In over-the-board chess, once you have deliberately touched a movable piece, you are committed to moving that piece, but you may still choose any legal square for that same piece until you release it. You cannot switch to a different piece after changing your mind.

Castling is a king move, so in over-the-board chess you should touch the king first. If you touch the rook first, you may lose the right to castle on that side for that move.

A touch-move claim should be made immediately, before the claimant touches a piece to reply. Waiting too long can mean the game continues without the violation being enforced.

If a touch-move issue is not raised and handled at the board, play usually continues. Tournament disputes depend on what is noticed, claimed, and ruled on in the moment.

The touch-move rule exists to keep over-the-board chess fair and orderly. It stops players from testing reactions with fake moves, reduces disputes, and makes physical-board play more disciplined.

Kasparov was widely accused of touching the d7-knight as if to play 36...Nc5 and then instead playing 36...Nf8. No successful claim was made during the game, so the game continued.

Modern engine analysis suggests 36...Nc5 was not simply losing and may have led to a drawish position. The famous controversy was about the touch-move issue itself more than a clearly lost move being escaped.