In a tournament, the chess clock measures each player's thinking time: it is pressed with the hand that made the move, and the player whose time runs out loses the game, unless the opponent can no longer checkmate. FIDE competitions are played with approved electronic clocks, such as the DGT 3000.
Chess clock, game clock, timer: the words vary, the object is the same. Two linked displays, only one running at a time, and each player stops theirs by pressing their button after moving. Behind this simple gesture, the FIDE Laws of Chess cover many situations: where to place the clock, what to do if it breaks down, when a loss on time becomes a draw. Here is what you need to know before playing or arbiting.
The rules for the chess clock in tournaments
- After each move, you stop your own clock, which starts your opponent's (Article 6.2.1). For illegal moves, a move is in fact only considered completed once the clock has been pressed.
- You press with the hand that made the move (Article 6.2): you cannot move with the right hand and press with the left to gain a fraction of a second.
- The arbiter decides where the clock goes before the game (Article 6.5). Traditionally, in individual tournaments, it is placed on the right of the player with Black.
- White starts the clock at the arbiter's signal. If a player is absent, their time runs down; beyond the default time set by the regulations, they lose the game. If nothing is specified, that default time is zero: you must be at your board at the start of the round (Article 6.7).
- You must not keep your hand on the clock or press it without having moved: pressing without moving is treated as an illegal move.
What happens when the flag falls?
Flag fall: a player's time has run out. On a mechanical clock a small red flag drops; on an electronic clock a symbol appears. The flag is considered to have fallen when the arbiter observes it or a player validly points it out.
The player whose flag falls before completing the required number of moves loses the game (Article 6.9). There is one important exception: the game is drawn if the opponent cannot checkmate by any sequence of legal moves, for instance if they have only a king left, or a king and a bishop. The arbiter must therefore look at the position before declaring the game lost. If a result (checkmate, stalemate, agreed draw) was reached before the flag fall was noticed, that result stands.
In classical play, the arbiter announces the flag fall as soon as they see it. In rapid and blitz, where the arbiter does not follow every game continuously, the player may claim a win on time themselves: they stop the clock and notify the arbiter, who also announces the flag fall if they observe it.
Breakdown, wrong setting and pause
A clock can break down or have been set incorrectly. The Laws of Chess provide that any indication given by the clock is deemed correct in the absence of an obvious defect; if a defect is evident, the arbiter replaces the clock and sets the times as best they can (Article 6.10). A player may stop the clock only to ask for the arbiter's help, for example when a promotion has taken place and the piece wanted is not available, or in the event of an irregularity or disturbance. A pause without good reason is penalised (Article 6.11). This is also why, in classical play, it is useful to keep your scoresheet up to date: it makes it possible to reconstruct the number of moves played.
Electronic clock or mechanical clock?
| Electronic | Mechanical | |
|---|---|---|
| Increment (Fischer time control) | Yes | No |
| Multi-stage time controls | Yes, on recent models | Only with manual adjustment by the arbiter |
| Display | Exact time, in seconds | Hands and flag |
| Use in FIDE competition | FIDE-approved models | Limited to time controls without increment |
| Strength | Precision, versatility | No batteries, looks, collector's item |
A mechanical clock, in wood or plastic, cannot add time on every move: it only suits time controls without increment. That is why approved tournaments are almost all played with an electronic clock. Wooden clocks and vintage models nonetheless keep their place in clubs, at home and with collectors, for friendly games or blitz without increment.
Approved models: the DGT 3000 and DGT 2010
In its Handbook, FIDE publishes standards for chess equipment and a list of certified equipment. Two clocks from the Dutch manufacturer DGT are ubiquitous in tournaments:
Fact sheet: DGT 3000 (manufacturer's data)
- Status
- Clock approved by FIDE
- Modes
- 24 preset settings and 5 customisable memories; Fischer increment, Bronstein delay, US delay
- Stages
- Handles multi-stage time controls
- Display
- Large 35 × 130 mm screen, seconds shown from the start
- Power
- Two 1.5 V AA batteries
- Warranty
- 5 years (manufacturer)
- Connection
- Compatible with DGT electronic boards for live broadcasting
The DGT 2010, its predecessor, remains very common in clubs: the manufacturer presents it as the official FIDE clock, compliant with the rules of the international federation, with Fischer and Bronstein modes. The big broadcast tournaments use the DGT 3000 connected to electronic boards, which send the moves live over the internet.
Setting a DGT 3000 to a Fischer time control
The principle is to select one of the preset Fischer options (for example 3 minutes + 2 seconds per move for blitz, or 1 h 30 + 30 seconds per move for a classical game), or to create a custom memory for a two-stage time control, then to check both displays before the round. The exact key sequence is in the manufacturer's manual; in a tournament, it is the arbiter who sets or checks the clocks before the first round, and it is one of the most time-consuming parts of the set-up.
Using and choosing a clock
To get started with a clock, Le Palais des Échecs offers a guide to using a chess clock: starting, setting, and the habits to build during a game. Those who want to equip themselves, players or clubs, will find its competition chess clocks, electronic or mechanical. A club preparing a tournament should plan one clock per board, plus a few spares: the page on organising a chess tournament details the equipment list.
The clock and time controls
The clock's main job is to apply the time control announced in the regulations: blitz, rapid or classical, with or without increment. The FIDE definitions and the 60-move rule are explained on the page about time controls in chess. In the event of a clock breakdown, a setting error or a dispute over time, the arbiter corrects the setting from the information available: see the arbiter and tournament rules.
Frequently asked questions
What happens when the flag falls in chess?
The player whose time has run out loses the game, unless the opponent cannot checkmate by any sequence of legal moves: the game is then drawn. If a checkmate, stalemate or agreed draw occurred before the flag fall was noticed, that result stands.
How do you set a DGT 3000 to a Fischer time control?
You choose one of the preset Fischer time controls (for example 3 min + 2 s or 1 h 30 + 30 s per move) or create a custom memory, then check the display on both sides before the game. The exact key sequence is described in the manufacturer's manual.
Which hand do you use to press the clock?
The hand that made the move, under Article 6.2 of the FIDE Laws of Chess. You may not move with one hand and press the clock with the other.
Can you play a tournament with a mechanical clock?
Only at a time control without increment, because a mechanical clock cannot add time on every move. Most approved tournaments use an increment and therefore electronic clocks.