Chess Clock Rules: How to Use a Chess Clock (FIDE and US Chess)

Chess clock rules made simple: move first, then press with the same hand. Flag falls, delay vs increment, clock etiquette and FIDE vs US Chess rules.

The basic chess clock rule is simple: make your move first, then press your side of the clock with the same hand you moved with. If your time runs out, your "flag falls" and you lose, unless your opponent could not checkmate you by any series of legal moves, in which case the game is a draw. Everything else, from delay settings to what happens when both flags fall, builds on those two ideas.

Below: setup, etiquette, and where FIDE (international) and US Chess rules differ. Rulebooks change and organizers add their own rules, so when a detail matters, check the rules of your event or ask the arbiter or tournament director (TD).

How to use a chess clock, step by step

1. Set the time before the game (see the setup section below).
2. Start White's clock when the round begins. In many US events, Black presses the button that starts White's time.
3. Make your whole move. Let go of the piece on its new square. For castling, both the king and the rook must be on their new squares. For a promotion, the new piece must be on the board.
4. Press your button with the same hand you used to move. This stops your time and starts your opponent's.
5. Take your hand away. Do not rest a finger on the button or hover over it while your opponent thinks.

The one-hand rule stops a player from moving with one hand while the other hovers over the clock, ready to slap it a split second later.

If you want to practice at home, our free online chess clock runs on any phone or laptop placed between two players and supports increment and delay.

What happens when your flag falls?

The "flag" is the little red lever on old analog clocks that dropped when time ran out; digital clocks show a flag symbol or 0:00.

When your flag falls, you normally lose the game. The big exception is insufficient mating material. Under the FIDE Laws, if your opponent cannot checkmate you by any possible series of legal moves, even with the worst defense from you, the game is a draw instead of a loss.

US Chess applies the same idea with its own, somewhat more generous list (rule 14E in the US Chess rulebook). The most common case: if the player with time left has only a king plus a single knight or bishop, a flag fall is normally scored as a draw in US Chess even when the flagged player still has pieces or pawns, as long as there is no forced win on the board. Under FIDE rules the same flag fall usually loses, because a checkmate is still possible if the flagged player helps it along.

For the full list of drawn endings, including dead positions, see our guide to draw rules.

Who can call the flag?

Under FIDE rules, a flag counts as fallen when the arbiter sees it or when a player makes a valid claim, so an arbiter watching your game may end it on time.

US Chess is different: in most situations only the players may point out a fallen flag. The TD, spectators, teammates and parents must stay silent. If your opponent's time has run out, it is up to you to say so, usually by stopping the clock and calmly saying "flag" or "time". In time controls with a move requirement, such as 40 moves in 2 hours, the player claiming a win on time generally needs a reasonably complete scoresheet to show that the moves were not made.

What if both flags fall?

If both flags are down in the last time period and it cannot be shown which one fell first, the game is normally a draw, under both FIDE and US Chess rules. In an earlier period, the game usually continues. Many digital clocks show which side ran out first, which settles most cases, but the exact procedure depends on the rulebook and the clock, so ask the arbiter.

Increment vs delay: how to set up the clock

Most modern games add something per move, and setting the wrong mode is a classic tournament mistake.

• Increment (Fischer mode): a fixed number of seconds is added after each move. With G/90;+30, each player starts with 90 minutes and gains 30 seconds per move, so fast moves let you build up time. This is the FIDE norm.
• Delay: the clock waits a few seconds before it starts counting down, so you lose no time if you move within the delay, but you can never gain time. With G/60;d5, a move made in 3 seconds costs nothing; a move made in 12 seconds costs 7.

Delay is the traditional US Chess standard, and G/xx;d5 is the most common format at US weekend and scholastic events. Increment time controls are increasingly common in US events too. The notation itself is explained in our guide to chess time controls.

Simple (US) delay vs Bronstein delay

Delay clocks offer two modes that give the same result in different ways:

• Simple delay (often labeled "US delay" or "delay"): after the opponent presses, your clock pauses for the delay, then starts counting down.
• Bronstein delay: your clock starts counting down at once, and when you press it, the time you used is given back, up to the delay amount.

Both end each move with the same time, and neither lets you finish a move with more time than you started it with. Simple delay is easier to read, so it is the usual US choice.

Setting up a typical game

• Pick the mode first: increment, simple delay or Bronstein.
• Enter each player's base time, then the seconds of increment or delay.
• For two-period controls such as 40/90, SD/30;+30, use the clock's multi-period preset.
• Compare both sides of the display with your opponent before the first move.

Which side does the clock go on?

Under FIDE rules, the arbiter decides where the clock is placed, and in most events every clock in the hall faces the same way so the arbiters can see them. In US Chess events, Black usually chooses which side the clock goes on, unless the TD has set it up differently. Players often pick the side away from their writing hand. If you are unsure who chooses, ask before the first move.

Clock etiquette and common problems

Pressing before moving. Pressing the clock without completing a move is not allowed. Under FIDE rules, pressing the clock without making a move is treated like an illegal move. In US Chess events, your clock is restarted and the TD may give a penalty. Penalties for illegal moves themselves also differ: under FIDE standard rules, the first completed illegal move usually gives your opponent two extra minutes and a second one loses the game, while US Chess and fast-chess rules have their own procedures. Check the rules of your event.

Slamming and hovering. Press firmly but not hard. Banging the clock or holding your hand over it is poor manners and can be penalized.

Touching your opponent's side. Never press your opponent's button or fiddle with the clock settings. The touch-move rule covers the board; the clock has rules of its own, and only the arbiter or TD should adjust it.

Knocking over pieces or the clock. If you knock pieces over, put them back on your own time. If the clock is knocked over or a button gets pressed by accident, stop the clock, set it upright and call the arbiter or TD to confirm the times. A player who causes this repeatedly can be penalized.

Stopping the clock. You may pause both clocks to get help from the arbiter or TD, for example to claim a draw or a flag, or to ask for a queen when you promote and none is on the table. Never stop it just to think.

Clock malfunction. If the display freezes, resets, or runs the wrong time control, stop the clock and call the arbiter or TD, who will reset it and decide the remaining times, often from the scoresheets. Do not fix it yourself, even if your opponent agrees.

Scholastic tips for kids and parents

US scholastic events nearly always use delay clocks, often with formats like G/30;d5 or G/60;d5. A few habits make a big difference for young players:

• Practice at home. Ten games with a chess clock before the first tournament remove most of the nerves. Practice "move, then press, same hand" until it is automatic.
• Watch the clock without panicking. Glance at it every few moves; a time advantage means nothing if a hurried move hangs the queen.
• Learn to call a flag. Kids should know they may stop the clock, say "flag", and raise a hand for the TD. Parents and coaches may not point out a fallen flag or comment on the clock during play.
• Keep score, then stop when allowed. Under US Chess rules, a player with under five minutes left in a sudden-death control with less than 30 seconds of delay or increment does not have to keep score.
• Know how long games last. Our guide to how long a chess game lasts helps parents plan a tournament day.