A draw by repetition is a chess rule that allows a player to claim a draw when the same position — including the same side to move, the same castling rights, and the same en passant possibilities — occurs three times during the game. It is also known as the "threefold repetition rule."
The three occurrences do not need to be consecutive. In over-the-board play, the draw is not automatic: it must be claimed by the player who is about to make the move that would create the third repetition, or by the player whose turn it is after the position has appeared for the third time. The claim is made to the arbiter. In online chess, platforms typically detect the repetition and declare the draw automatically.
In practice, draw by repetition most often arises in tense endgames or through a sequence of checks (see: perpetual check). A player in a losing position may deliberately steer toward repeated moves to escape defeat, while a player with a winning advantage must stay alert and avoid accidentally repeating positions.