Chess Clock Rules: Increment, Delay, Blitz and Rapid Explained

"3+2" looks like a sum, and in a way it is. The first number is how many minutes each player starts with. The second is how many seconds each move earns. Everything else about chess time controls, from bullet to world championship classical, is a variation on those two numbers and on how the seconds are added.

This guide covers the rules of the clock itself, the three ways of adding time, how FIDE sorts games into blitz, rapid and standard, and which control suits which kind of game.

What the clock rules say

The FIDE Laws of Chess (the 2023 edition) define a chessclock as "a clock with two time displays, connected to each other in such a way that only one of them can run at a time." A few rules in Article 6 cover most of what casual players need:

Pressing the clock completes your move. After moving, you stop your own clock and start your opponent's (6.2.1).
Use the same hand you moved with to press the clock (6.2.3), and don't keep your finger on it or hover over it.
Pausing is only for getting the arbiter's help (6.11.2). In a friendly game, that translates to "pause for a real problem, not to think".
Running out of time loses, with one big exception: if your opponent couldn't checkmate you by any possible series of legal moves, the game is a draw (6.9). A lone king can't win on time.

Three ways to add time

A clock with no added time is called sudden death: when your time is gone, it's gone. Modern controls almost always add time per move, in one of three ways.

Fischer increment. A fixed amount is added for every move, however quickly you made it. Move fast and you bank time. FIDE's glossary calls this "cumulative (Fischer) mode". It's named after Bobby Fischer, who filed a US patent for a digital clock that added a set amount after each move in 1988 (granted in 1989); the patent's stated aim was to do away with frantic time scrambles.

Bronstein delay. After each move you get back the time you used, up to the delay amount. If you move within the delay, your clock returns to exactly where it was; if you take longer, you get the full delay back. Your clock can never go up.

Simple delay (also called US delay). Each time your clock is started, it waits for the delay before counting down. Move within the delay and your main time doesn't change at all.

Bronstein and simple delay give the same result for every move. The US Chess rulebook says the two are "mathematically equivalent" and differ only in what the display shows while the clock runs. The difference from Fischer is the one that matters: with delay, your main time never goes above what it was at the start of the move. With increment, it can.

Here's what happens to a clock showing 3:00 with a 2-second increment or delay:

Mode	Move takes 1.5 s	Move takes 5 s
Sudden death (no added time)	2:58.5	2:55.0
Fischer +2	3:00.5 (gained time)	2:57.0
Bronstein 2 s	3:00.0	2:57.0
Simple delay 2 s	3:00.0	2:57.0

Among the three ways of adding time, the only difference is the fast move. Fischer rewards it with half a second in the bank; the delay modes just hold you level. In a long endgame where both players are moving instantly, that adds up: under increment, a player with a few seconds left can rebuild a buffer by moving quickly, while under delay they can only hold steady.

One small detail if you're comparing rules and apps: FIDE's glossary describes increment as time "added from the start before each move", while many clocks and apps, ours included, add it when you press after your move. Either way, every move earns the same increment.

Blitz, rapid and standard

FIDE sorts games by the total time each player would use in a 60-move game: the starting time plus 60 times the increment. Because 60 moves × 1 second is 1 minute, the shortcut is easy: add the increment in seconds to the base in minutes.

Blitz: 10 minutes or less per player (Appendix B).
Rapid: more than 10 and less than 60 minutes (Appendix A).
Standard (often called classical): at least 60 minutes per player (Glossary).

FIDE doesn't have a "bullet" category; its blitz covers everything up to 10 minutes. Online sites split it further. Lichess, for example, estimates game length as the starting time plus 40 times the increment, and calls anything up to 179 seconds bullet, up to 479 seconds blitz, up to 1,499 seconds rapid and anything longer classical.

Control	FIDE total	FIDE category	Lichess estimate	Lichess category
1+0	1 min	Blitz	60 s	Bullet
2+1	3 min	Blitz	160 s	Bullet
3+0	3 min	Blitz	180 s	Blitz
3+2	5 min	Blitz	260 s	Blitz
5+3	8 min	Blitz	420 s	Blitz
10+0	10 min	Blitz	600 s	Rapid
10+5	15 min	Rapid	800 s	Rapid
15+10	25 min	Rapid	1,000 s	Rapid
90+30	120 min	Standard	6,600 s	Classical

Note 10+0: online it's rapid, but under FIDE's "10 minutes or less" wording it's blitz.

In the US, US Chess uses the same "minutes plus seconds" sum to decide which rating a game counts for: more than 65 minutes is regular, 30 to 65 is dual-rated, more than 10 and less than 30 is quick, and 5 to 10 minutes is blitz.

Common presets and when to use them

1+0 and 2+1 (bullet). Mostly an online format. On a real board, a minute each means pieces flying and clocks being slammed; fun, but not a test of chess.

3+2 (blitz). The control used for the FIDE World Blitz Championship in 2025. The two-second increment means a won position can almost always be converted without losing on time. It's the best default for a quick game between club players.

5+3 and 5+0 (blitz). A bit more room to think. Without an increment, the last minute is often decided by speed rather than chess.

10+5 (rapid). A good club-night game: long enough for real thought, short enough to fit several rounds in an evening.

15+10 (rapid). The control for the FIDE World Rapid Championship in 2025. Generous enough to play proper chess with little risk of losing on time.

30 minutes with 5 seconds delay. Written "G/30 d/5", it's one of the standard examples in the US Chess rulebook, which treats a 5-second delay as standard for regular and dual-rated games and 3 seconds for quick games. Choose delay over increment if you want clocks that never grow.

90+30 (standard). 90 minutes plus 30 seconds a move gives each player 120 minutes over 60 moves. FIDE's rating regulations require at least 60, 90 or 120 minutes per player for a 60-move game, depending on the players' ratings (below 1800, 1800 to 2399, and 2400 and above), so 90+30 qualifies at every level.

What if there's no increment?

Sudden death is fine for casual play, but it produces scrambles where the player with more time wins a lost position. FIDE has a fallback for standard and rapid games played without increment: under Guidelines III, a player with less than two minutes left may ask for a five-second increment to be added for both players. That request also counts as a draw offer. If you're setting up a game at home, the simpler answer is to add a small increment from the start.

Picking a control for your game

Teaching a beginner: 15+10 or longer, or no clock at all. The clock is a second skill.
Club players, one evening: 10+5 for a few serious games, 3+2 for a lot of quick ones.
Over the board: always use some increment or delay; it removes most arguments about flags in won positions.

Try it

Our free chess clock runs on a phone or laptop between the two players, with presets from bullet to classical and Fischer, Bronstein, delay or no added time. It shows which FIDE category your settings fall into, works with the Shift keys and Space on a keyboard, and keeps exact time even if the screen dims or you switch apps. The time control lives in the link, so you can share a setup: 3+2 blitz, 10+5 rapid or 30 minutes with 5 seconds delay.

For timed practice away from the board, such as puzzle sprints, the interval timer runs rounds with rests in between.

Sources

FIDE (2023). FIDE Laws of Chess, taking effect from 1 January 2023: Article 6 (the chessclock), Appendix A (rapid), Appendix B (blitz), Guidelines III (games without increment) and Glossary. handbook.fide.com
FIDE (2024). FIDE Rating Regulations, effective from 1 March 2024, Article 1 (rate of play). handbook.fide.com
FIDE (2025). Regulations for the FIDE World Rapid & Blitz Championships 2025. handbook.fide.com
US Chess Federation (2024). US Chess Federation's Official Rules of Chess, 7th edition, online edition: rules 5B (delay and increment) and 5C (ratable time controls). new.uschess.org
Fischer, R. J. (1989). Digital chess clock. US Patent 4,884,255, filed 5 August 1988, granted 28 November 1989. Google Patents
Lichess. Frequently asked questions: time controls. lichess.org