The FIDE Laws of Chess
         
 

Article 7:   Irregularities

7.1 

  • a.  If during a game it is found that the initial position of the pieces was incorrect, the game shall be cancelled and a new game played. 
  • b.  If during a game it is found that the only error is that the chessboard has been placedcontrary to Article 2.1, the game continues but the position reached must be transferred to a correctly placed chessboard. 
7.2  If a game has begun with colours reversed, then it shall continue, unless the arbiter rules otherwise. 

7.3  If a player displaces one or more pieces, he shall re-establish the correct position on his own time. If necessary, either the player or his opponent shall stop the clocks and ask for the arbiter's assistance. The arbiter may penalise the player who displaced the pieces. 

7.4

  • a.  If during a game it is found that an illegal move has been made, the position immediately before the irregularity shall be reinstated. If  the position immediately before the irregularity cannot be determined the game shall continue from the last identifiable position prior to the irregularity. The clocks shall be adjusted according to Article 6.14. Article 4.3 applies to the move replacing the illegal move. The game shall then continue from this reinstated position. 
  • b.  After the action taken under Article 7.4(a), for the first two illegal moves by a player the arbiter shall give two minutes extra time to his opponent in each instance; for a third illegal move by the same player, the arbiter shall declare the game lost by this player. 


7.5  If during a game it is found that pieces have been displaced from their squares, the position before the irregularity shall be re-instated. If the position immediately before the irregularity cannot be identified, the game shall continue from the last identifiable position prior to the irregularity. 
The clocks shall be adjusted according to Article 6.14. The game shall then continue from this re-instated position.