Rules 09: The drawn game
9.1. A player can propose a draw after making a move on the chessboard. He must do so before stopping his own clock and starting his opponent's clock. An offer at any other time during play is still valid, but Article 12.5 must be considered. No conditions can be attached to the offer. In both cases the offer cannot be withdrawn and remains valid until the opponent accepts it, rejects it orally, rejects it by making a move, or the game is concluded in some other way.
The offer of a draw shall be noted by each player on his scoresheet with the symbol (=).
9.2. The game is drawn, upon a correct claim by the player having the move, when the same position, for at least the third time (not necessarily by repetition of moves)
(a) is about to appear, if he first writes his move on his scoresheet and declares to the arbiter his intention to make this move, or
(b) has just appeared.
Positions as in (a) and (b) are considered the same, if the same player has the move, pieces of the same kind and colour occupy the same squares, and the possible moves of all the pieces of both players are the same. Positions are not the same if a pawn could have been captured en passant or if the right to castle immediately or in the future has been changed.
9.3. The game is drawn, upon a correct claim by the player having the move, if
(a) he writes on his scoresheet, and declares to the arbiter his intention to make a move which shall result in the last 50 moves having been made by each player without the movement of any pawn and without the capture of any piece, or
(b) the last 50 consecutive moves have been made by each player without the movement of any pawn and without the capture of any piece.
9.4. If the player makes a move without having claimed the draw he loses the right to claim, as in Article 9.2 or 9.3, on that move .
9.5. If a player claims a draw as in Article 9.2 or 9.3 he shall immediately stop both clocks. He is not allowed to withdraw his claim.
(a) If the claim is found to be correct the game is immediately drawn.
(b) If the claim is found to be incorrect, the arbiter shall deduct half of the claimant's remaining time up to a maximum of three minutes and add three minutes to the opponent's remaining time. Then the game shall continue and the intended move must be made.
9.6. The game is drawn when a position is reached from which a checkmate cannot occur by any possible series of legal moves, even with the most unskilled play. This immediately ends the game.