The fifty-move rule

If fifty moves go by for each player with no pawn moved and nothing captured, either player may claim a draw. It is the rule that stops a player with no plan from playing until midnight.

50 moves each
Pawn move or capture resets it
75 is automatic

Fifty moves by White and fifty by Black, one hundred half moves in all, with no pawn move by either side and no capture of any kind. Once that happens either player may claim a draw. It does not happen automatically, and it does not stop the game if nobody asks.

Two things reset it, and only two

Any pawn move. A push or a pawn capture, by either player.
Any capture. Of any piece, by any piece, either colour.

Nothing else touches it. Checks do not reset it, castling does not reset it, promoting a pawn resets it because promoting involves moving a pawn. A hundred quiet king moves in a row change nothing.

Watch the counter

Four quiet moves and one pawn move

A rook endgame with the counter already at 45. Four quiet moves take it to 49, and then one pawn push puts it back to zero. These are the engine's own numbers, read out of the position after every half move.

80.Rh5 Kg7 81.Rh4 Kf7 82.e4

80.Rh5 → counter 46
Kg7 → counter 47
81.Rh4 → counter 48
Kf7 → counter 49
82.e4 → counter 0 the counter goes back to zero

The counter shown here counts half moves, which is how every engine and every FEN string stores it: the rule triggers at 100. That is why a FEN has a number in its second to last field, and why you can tell at a glance how close a position is.

What it is actually for

Two things. It stops a player who cannot win from refusing to admit it, and it puts an upper bound on how long a game can last. Without it, a king and rook against a lone king could be shuffled indefinitely.

It also acts as the deadline in endgames that are genuinely won but take technique. King, bishop and knight against a bare king is a forced mate that takes up to 33 moves with perfect play, which fits inside fifty with room to spare, but not much room if you do not know the method.

The seventy-five move rule

Since 2014 there is an automatic version. If seventy-five moves pass for each side with no capture and no pawn move, the game is drawn immediately without either player claiming, unless the last move was checkmate. It exists so that arbiters can end games that are clearly going nowhere.

The endgames that broke it

Computer analysis has found forced wins that take more than fifty moves, such as some queen against rook and pawn positions and various positions with two knights against a pawn. FIDE experimented in the 1980s and 1990s with longer limits for specific material, then abandoned it as unworkable: an arbiter cannot be expected to know which of a hundred endings has an exception. The fifty-move rule is now uniform, and a handful of theoretically won positions are drawn by it. That is accepted as the price of a rule anyone can apply.

Questions people ask

What is the fifty-move rule in chess?

If fifty consecutive moves are played by each side with no pawn moved and no piece captured, either player may claim a draw. It is a claim, not an automatic result, although at seventy-five moves the draw does become automatic.

What resets the fifty-move counter?

Only two things: a pawn move by either side, or a capture of any kind. Checks, castling, and moving the king in and out of the same square do nothing at all to the counter.

Is the fifty-move rule automatic?

Not at fifty. Either player has to claim it, and the game continues if nobody does. At seventy-five moves it becomes automatic and the arbiter declares the draw. Online platforms usually apply it for you.

Does the fifty-move rule count each player's moves separately?

It counts fifty moves by each player, so one hundred half moves in total. Engines and FEN strings store it as a half move counter, which is why you will see the number 100 rather than 50 in technical writing.

Fifty-move rule sits under How a game ends in the reference. Nearby: