What happens if you make an illegal move in chess?
I · Intermediate · At the board · 6 of 7An illegal move is completed when the player presses the clock. The position is put back to where it was, and the player must make a legal move with the piece they touched if they can. The opponent gets two extra minutes. A second completed illegal move by the same player loses the game.
How it works
- Illegal move: one that breaks the rules for how pieces move or leaves the king in check.
- Completed: once the clock is pressed.
- Put back: the position before the mistake is restored. If it cannot be established, play resumes from the last position that can be.
- Touch-move applies: the replacement move must be with the touched piece if that is legal.
- First one: two minutes extra for the opponent.
- Second one by the same player: the game is lost, unless the opponent cannot possibly checkmate, when it is drawn.
- Counted as illegal moves: pressing the clock without moving, using two hands for one move and pressing the clock, and leaving a pawn unpromoted on the last rank.
- Found later: an illegal move discovered at any time during the game is corrected.
The glossary has the illegal move, the touch-move rule, the chess clock, the check, the promotion and the arbiter.
Tricky cases
An illegal move is noticed ten moves later in a standard game. What happens?
The game goes back to the position before the illegal move, and continues from there. The moves played since are lost.
A player makes an illegal move but has not pressed the clock. Is there a penalty?
No. The move is not completed until the clock is pressed. The player corrects it, with the touch-move rule applying.
In a blitz game a player makes an illegal move and the opponent replies without noticing. Can it be corrected?
No. In blitz and rapid without full supervision, once the opponent has made their next move the illegal move stands, unless both players agree to correct it.
A player presses the clock without making a move, to gain a second. Penalty?
Yes. It is "considered and penalised as if an illegal move".
Why the rule exists
A game built on an impossible move is not a game of chess, so the Laws wind it back. The time bonus compensates the opponent for the disruption. Making the second offence fatal stops illegal moves from being used on purpose in a time scramble.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Standard chess, first illegal move | Position restored; two minutes to the opponent | FIDE Laws 7.5.1; 7.5.5 |
| Second by the same player | Loss of the game | FIDE Laws 7.5.5 |
| Rapid and blitz | The time added is one minute | FIDE Laws A.3; B.3 |
| Rapid and blitz without full supervision | Must be claimed or seen before the opponent's next move, or it stands | FIDE Laws A.5.2; B.3 |
| Both kings in check, or a pawn on the last rank, in such games | The arbiter waits one move, then declares a draw if the position is still illegal | FIDE Laws A.5.4 |
From the rule book
FIDE, Laws of Chess (approved 7 August 2022, applied from 1 January 2023), Articles 3.10, 7.5 and 7.6 and Appendix A.3, A.5 and B.3. Checked 14 October 2026. Official document: FIDE Laws of Chess taking effect from 1 January 2023 (FIDE Handbook E.01).