Seventy-five–move rule

Seventy-five–move rule

Definition

The seventy-five–move rule is a FIDE law that declares a game drawn automatically if 75 consecutive moves by each side (i.e., 150 half‑moves/plies) occur without any pawn move or capture. If the move that would complete the 75th move also delivers checkmate, the checkmate takes precedence and the game is won, not drawn.

How it is used in chess

The rule operates alongside, and does not replace, the claimable fifty-move rule:

• After 50 consecutive moves by each side without a pawn move or capture, either player may claim a draw (not automatic).
• After 75 consecutive moves by each side without a pawn move or capture, the game is drawn automatically without any claim (unless the final move is checkmate).

Arbiters and digital platforms generally enforce the 75–move automatic draw. The count resets to zero whenever a pawn moves (including promotion) or any capture occurs (including en passant). Checks, castling, and piece moves that are not captures do not reset the counter.

Strategic significance

• Endgame defense: The defender often aims to avoid pawn moves and captures to “run down the clock” on the 50/75–move counters. If you can hold a fortress or keep shuffling pieces without conceding a capture or pawn move, you may draw by rule.
• Endgame technique for the stronger side: Aim to force a reset by provoking a pawn move or inducing/taking a capture, then continue pressing. Practical wins often hinge on engineering such a reset before the counters become critical.
• Tablebase awareness: Some theoretically winning endgames (ignoring the rules) require more than 50 moves without a reset to convert. With the modern rules, these are drawn if the defender claims at 50 (or they become automatic at 75 if no one claims). Thus, “tablebase win” does not always equal “win under FIDE rules without cooperation.”

Historical notes

For most of chess history the framework centered on the 50–move rule, with various exceptions in the mid–20th century that allowed extended move counts (often up to 100 moves) in specific endgames like rook and bishop vs rook or two knights vs a pawn. These exceptions were abolished in the early 1990s to simplify the laws. In the mid‑2010s, FIDE introduced two automatic conditions: the 75–move automatic draw (complementing the 50–move claim) and automatic draw by fivefold repetition (complementing the claimable threefold repetition). The aim was to prevent games from continuing indefinitely when neither player claims a draw.

Examples and scenarios

• Counting example: Suppose the last capture happened on move 32...Qxd4. If neither side makes any further capture or pawn move, then:
  • On completing White’s 57th move (i.e., after 25 more full moves each since move 32), either player may claim a draw by the 50–move rule.
  • On completing White’s 82nd move (i.e., after 50 more full moves each since move 32), the game is drawn automatically by the 75–move rule—unless that move is checkmate.
• Practical endgame: In rook and bishop vs rook, tablebases reveal some positions that require more than 50 moves without a capture or pawn move to convert. Against correct defense, these are drawn in practice if the defender claims at 50; however, if the defender forgets to claim and the stronger side mates on, say, move 60, the win stands because the 75–move automatic trigger has not yet been reached.
• Checkmate overrides: Imagine a locked position with no pawn moves or captures for a long stretch; on the 75th move since the last reset, White delivers a mating net with Qh7#. The game is a win for White, not a draw, because checkmate overrides the automatic draw condition.

Common misconceptions and tips

• “Move” vs “half‑move”: The 75–move rule counts full moves by each side (150 plies). The FEN “halfmove clock” field tracks the number of plies since the last pawn move or capture; when it reaches 150, the 75–move condition is met.
• You cannot retroactively claim 50–move after you have played on; once you make a move, your earlier right to claim is gone. The game only ends automatically at 75 if no reset occurs.
• Promotions reset the count because a pawn moved; castling does not reset the count because no pawn moved and no capture occurred.
• Related rule: Fivefold repetition is automatic; threefold repetition requires a claim—mirroring the 75/50 relationship.

Interesting facts

• Tablebase discoveries show that some seven‑man positions require far more than 50 moves without a capture or pawn move to force mate with perfect play. Under modern rules, such wins are theoretically drawn if the defender manages the 50/75–move counters.
• The 75–move automatic draw was introduced to prevent rare but awkward situations in which neither player knew (or chose) to claim the 50–move draw while the position remained sterile for dozens more moves.
• Defensive technique in difficult endings often includes “freeze the pawn structure” and “avoid exchanges” to keep the counter ticking upward toward 50 and 75, forcing the attacker to find a reset or settle for a draw.

Related terms

See also: fifty-move rule and fivefold repetition.