Article 9: The drawn game

9.1	a.	The rules of a competition may specify that players cannot agree to a draw, whether in less than a specified number of moves or at all, without the consent of the arbiter.
	b.	If the rules of a competition allow a draw agreement the following apply: A player wishing to offer a draw shall do so after having made a move on the chessboard and before stopping his clock and starting the opponent’s clock. An offer at any other time during play is still valid but Article 12.6 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 In both cases the offer cannot be withdrawn and remains valid until the opponent accepts it, rejects it orally, rejects it by touching a piece with the intention of moving or capturing it, or the game is concluded in some other way. The offer of a draw shall be noted by each player on his scoresheet with a symbol. (See Appendix C.13) A claim of a draw under Article 9.2, 9.3 or 10.2 shall be considered to be an offer of a draw.
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 a 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, and the player claiming the draw has the move.
	Positions as in (a) and (b) areconsidered 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 that could have been captured en passant can no longer be captured in this manner. When a king or a rook is forced to move, it will lose its castling rights, if any, only after it is moved.
9.3	The game is drawn, upon a correct claim by the player having the move, if:
	a.	he writes his move on his scoresheet and declares to the arbiter his intention to make this move, which shall result in thelast50 moves having been made by each player without the movement of any pawn and without any capture, or
	b.	the last 50 consecutive moves have been made by each player without the movement of any pawn and without any capture.
9.4	If the player touches a piece as in Article 4.3 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 may stop both clocks. (See Article 6.12.b) 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 add three minutes to the opponent’s remaining thinking time. Then the game shall continue. If the claim was based on an intended move, this move must be made as according to Article 4.
9.6	The game is drawn when a position is reached from which a checkmate cannot occur by any possible series of legal moves. This immediately ends the game, provided that the move producing this position was legal.

Note: This is an excerpt from the FIDE Handbook. For actual handbook click here