The short answer
A chess clock gives each player a thinking-time budget. Learn the time control before starting, keep move completion separate from thinking time, and know which procedure settles a timeout.
A chess clock contains two linked timers. Normally one runs while the other waits, so each player spends their own allowance deciding what to do. The clock adds a practical challenge to finding good moves: you must also decide how much time each decision deserves.
The numbers beside a game matter as much as the board setup. Five minutes with an increment plays differently from five minutes with no extra time. Before starting, check the initial allowance, any increment or delay, and whether the game uses a live clock at all. Procedures differ between physical tournaments and online platforms.
Read minutes and seconds in the right order
In the familiar 5+3 format, the first number is minutes of initial thinking time and the second is seconds of increment per move. Both players normally receive that allowance separately. It does not mean five minutes shared between the players, and the three is not three extra minutes. A 10+5 game gives each player ten initial minutes and a five-second increment.
A plain label such as 5+0 has no increment. Some events use several stages, adding a new time allowance after a specified number of moves. Read the full description if one is supplied; a short label cannot explain every tournament setting. Untimed play has no live thinking-time countdown and is a good way to learn unfamiliar rules.
| Label | Initial time per player | Extra time |
|---|---|---|
| 5+0 | Five minutes | None per move |
| 5+3 | Five minutes | Three seconds per completed move |
| 10+5 | Ten minutes | Five seconds per completed move |
| Untimed | No live countdown | No clock budget to manage |
Worked example: spending time with an increment
Suppose your clock shows thirty seconds in a game with a three-second increment. You spend seven seconds choosing and completing a move. That leaves twenty-three seconds before the increment, then twenty-six after it is credited. If your next move takes only one second, the three-second addition can leave you with more time than you had at the start of that turn.
This does not give you permission to run out first and recover with an increment afterwards. The move must meet the game’s time and completion rules. Online servers decide when a move is accepted; physical events have their own clock and flag-fall procedures. Check how your particular clock displays and applies the increment rather than relying on a last-second assumption.
A delay does not behave like an increment
With a simple delay, the main time does not start decreasing until the delay period has been used. Imagine thirty seconds remaining and a five-second delay. A move taking three seconds leaves the main allowance at thirty. A move taking eight seconds uses the five-second delay plus three seconds of main time, leaving twenty-seven.
Unused delay is not saved up as extra main time for a later move. By contrast, a credited increment can build your remaining allowance when you move quickly. Clock hardware and event descriptions may distinguish specific delay systems, so confirm the actual setting instead of treating every “extra five seconds” description as identical.
Build a calm physical-board routine
In normal over-the-board play, make the board move first, then press your side of the clock with the same hand. Do not press before completing the move or hold a finger over the button while thinking. The interval before you press normally belongs to your time. Practise this sequence slowly so the clock does not distract you from placing the piece correctly.
A valid game-ending move, such as checkmate, ends the game without needing a further clock press to create the result. If there is a disagreement about timing, legality or which event happened first, preserve the position and ask the arbiter. Do not invent a penalty, repeatedly press buttons or change the clock settings yourself.
Running out usually loses, with a precise exception
Under FIDE rules, failing to complete the required moves in time normally loses. The exception is when the opponent cannot checkmate your king through any possible legal sequence. That is a draw. The question is not who has more material, who was winning, or whether the opponent can force mate against perfect defence.
A bare king cannot deliver checkmate, so a player facing only a bare king does not lose on time under that rule. Two knights illustrate the opposite distinction: they can participate in a legal mating position against a bare king, despite generally lacking a forced mate. With other material or blocked positions, possible-mate analysis can be subtler than counting pieces.
Worked example: possible mate is enough
The diagram shows White’s king on f7, knights on f6 and g6, and Black’s king on h8. The knight on g6 checks h8. White’s king covers g8 and g7, and the knight on f6 covers h7. Black is checkmated. This is evidence that a legal mating arrangement with two knights exists, not a claim that White can force it from any two-knight position.
The pictured game has already ended, so no clock should still be deciding its result. Use it only to understand the word “possible” in the timeout rule. A claim that “two knights cannot force mate, therefore every timeout must be a draw” confuses two different tests.
Online clocks are live even during review
In online play, the service’s accepted move and server timing determine the live result. A connection problem, an animation or a local display does not itself prove that the clock stopped. Check the platform’s reconnection and timing policies. Never assume you can pause a rated or multiplayer game by leaving the page or looking at a different board.
Studying an earlier move also does not pause a live opponent game. Treat a historical board as a review view while the actual match continues. Theme Chess beta offers untimed play, 5+3 and 10+5 presets; its timeout check uses material-based rules rather than an exhaustive solver for every FIDE possible-mate exception. The general FIDE explanation here is not a promise of complete tournament adjudication by the beta.
Blitz and rapid labels can depend on the rule set
FIDE speed categories account for the initial time plus sixty increments. For example, 5+3 gives five minutes plus three more minutes from sixty increments: eight minutes for classification, within blitz. A 10+5 control gives ten plus five minutes: fifteen minutes, within rapid. This calculation classifies the control; it does not guarantee the actual game will last sixty moves.
FIDE’s rapid band is above ten and below sixty minutes per player on that basis; blitz is ten minutes or less. Websites may use their own labels for categories such as bullet or may classify a boundary differently. Read the actual time control when comparing games rather than assuming a category name tells the whole story.
A little extra clarity
Common questions
What does 5+3 mean?
Usually five minutes of initial time for each player plus a three-second increment per completed move. Confirm the exact settings before starting.
Can my remaining time increase?
Yes, with an increment. If a move takes less time than the increment credited for it, your remaining allowance can grow.
Does running out always lose?
Not under FIDE rules. It is a draw if the opponent cannot possibly deliver checkmate through any legal sequence. Online platforms may implement their own adjudication procedures.
Does reviewing an earlier move stop a live clock?
No. A historical board view is for study, not a pause request. The live match and its clock continue unless an actual game rule or authorised pause says otherwise.
Should beginners start with very fast games?
A comfortable time allowance usually gives you more room to check legality and learn from decisions. Add speed after you can handle the board and clock routine confidently.
Sources and further reading
Official rules and the references used for this guide.
Written by the Theme Chess team. Explanations help you learn; the linked rules remain the reference for formal play.