CurlTi.me/Learn/Rules and officials
The rulebook, clocks and umpires
The rules of curling are seventy pages, free to download, and unusually well written. Almost nobody reads them. Here is the map, and the three chapters worth knowing by heart.
Last updated 2026-08-18
The document#
The Rules of Curling and Rules of Competition is published by World Curling, revised every July, and free. It is about seventy pages and it is organised so that a specific question is answerable in under a minute — once you know which chapter to open.
| Rule | Subject | What is in it |
|---|---|---|
| R1 | Sheet | Every dimension, in metres and feet. |
| R2 | Stones | Weight, size, damage, what happens when one breaks. |
| R3 | Teams | Composition, alternates, and the elaborate procedures for a player who cannot finish. |
| R4 | Position of players | Where everybody stands, and the penalty for standing wrong. |
| R5 | Delivery | The hack, the hog line release, wrong stone, wrong order, too many stones. |
| R6 | Free guard zone | The five-rock rule. |
| R7 | No-tick shot | The loophole closer. |
| R8 | Sweeping | Who may sweep what, where, and what counts as a violation. |
| R9 | Touched moving stones | Burned stones — the largest and most-consulted rule. |
| R10 | Displaced stationary stones | The other half of the same problem. |
| R11 | Equipment | Ice damage, electronics, hog line sensors, delivery sticks. |
| R12 | Scoring | Counting, measuring, ties, concession, arriving late. |
| R13 | Interrupted games | When the building has a problem. |
| R14–R17 | Wheelchair, wheelchair mixed doubles, mixed, mixed doubles | The other disciplines. |
| R18–R19 | Prohibited substances, inappropriate behaviour | Short, and rarely needed. |
| C1–C10 | Rules of Competition | Uniforms, practice, game length, timing, time-outs, stone assignment, rankings, umpires. |
Two structural things worth knowing. The R chapters are the game and apply anywhere the rules are adopted; the C chapters are how World Curling runs its own competitions and mostly do not apply at your club. And there is a full glossary at the back, which settles more arguments than any other four pages in curling — the terms it defines are marked in our glossary too.
The clock#
Competitive curling is timed like chess, not like football. Each team has a budget of thinking time, and it runs only while that team is deciding.
- 38 minthinking time, ten-end game
- 30 mineight-end game
- 22 minmixed doubles
- 4:30added per extra end
When it runs, exactly#
Your clock starts once all of the following are true:
- every stone has stopped, or crossed the back line;
- any stones displaced by the other team's violations are back where they belong;
- the other team has relinquished the playing area — their skip has moved behind the back line, and their thrower and sweepers are at the sides.
It stops the instant your stone reaches the tee line at the delivery end — the hog line in wheelchair curling.
Delivering and sweeping are free. Only deciding costs you. So a team under time pressure does not throw faster — it stops discussing, which is exactly the pressure the system is designed to apply.
Breaks, time-outs and running out#
- Between ends: one minute, clocks stopped. Mixed doubles gets an extra 30 seconds because somebody has to place the positioned stones.
- Halfway: five minutes, after the fifth end in a ten-end game. Seven minutes in wheelchair mixed doubles.
- Team time-out: one per game, plus one per extra end. Sixty seconds, plus a travel-time allowance set by the chief umpire so a coach can reach the sheet. Signalled with a "T" with the hands, and only by a player on the ice, and only while your own clock is running.
- Technical time-out: for a ruling, an injury, or similar. Clocks stop. Called by a team or an umpire.
- Running out: you forfeit. A stone that reaches the tee line before time expires counts as delivered in time.
There is also a rule for teams that are simply dawdling without being short of time: if an umpire warns a team for unnecessary delay, and the next stone has not reached the tee line within 45 seconds, that stone is removed from play.
Timing errors are handled generously and asymmetrically, which is a nice piece of drafting: a team whose clock ran wrongly gets double the error time added back, while a team whose clock failed to run has nothing deducted — the time is added to the opponent instead.
Measuring#
The measure pivots on the pin at the centre of the house and swings out to the nearest part of each stone. Distance is always measured from the tee, never between stones.
The timing restriction is the part people get wrong. A measuring device may only be used once the last stone of the end has come to rest — with two narrow exceptions, both about legality rather than score:
- to determine whether a stone is in play at all;
- before the second, third, fourth or fifth stone of an end, to determine whether a stone is in the free guard zone or the no-tick zone.
Until then, stones are judged by eye. This is why you see skips crouching and squinting rather than reaching for equipment: they are not being traditional, they are following R2(i).
When the device will not fit, and exact ties#
If two stones are so close to the tee that a measuring device physically cannot be used, the call is made visually. If no decision can be reached at all, the stones are considered equal, and:
| What the measure was for | Result of an exact tie |
|---|---|
| Deciding which team scored | The end is blanked. |
| Deciding an additional point | Only the stones already closer count. |
One player from each team may watch any measurement. And if somebody displaces a stone before the score has been agreed, the non-offending team gets the benefit of whatever the measurement might have given them — which is a nicely blunt way of removing any incentive to knock the measure over.
When a stone moves that should not have#
Two chapters, R9 and R10, cover the whole space between them, and the taxonomy is worth learning because the answers genuinely differ.
| What happened | Where | What happens |
|---|---|---|
| Your team touches a moving stone | Between the delivery tee line and the far hog line | The touched stone is removed immediately, by your team. A double touch by the thrower before the near hog line is not a violation. |
| Your team touches a moving stone | Inside the far hog line | Everything stops. The other team chooses: remove the touched stone, leave everything as it lies, or place all stones where they judge they would have finished. |
| The other team touches your moving stone | Before the far hog line | If it was the delivered stone, you throw it again. If not, it is placed where your team reasonably judges it would have stopped. |
| The other team touches your moving stone | Inside the far hog line | Your team places all stones where you reasonably judge they would have finished. |
| A stationary stone is displaced and it would not have mattered | Anywhere | It goes back, replaced by the non-offending team. |
| A stationary stone is displaced and it would have altered a moving stone’s course | Anywhere | The non-offending team chooses from three options, including placing every stone where they judge it would have ended up. |
| An external force — anything not caused by either team | Anywhere | Stones are put where they would have finished. If the teams cannot agree, the stone is redelivered. If they cannot agree on that either, the end is replayed. |
The non-offending team decides, and the remedy is restoration rather than punishment. Curling almost never awards a penalty; it puts the position back and carries on. This is a direct consequence of the Spirit of Curling, which assumes the offence was an accident and that the offender reported it.
Umpires#
Curling has umpires, and mostly does not use them. Officiated play is defined as one game umpire per sheet for an entire session, and that happens at major competition and essentially nowhere else. Every league game, every bonspiel, every Tuesday night in every club in the world is played without an official on the ice.
Where umpires do exist, their job is narrower than a referee's in most sports. They rule when asked, they watch for sweeping violations, they run the timing, they conduct measurements, and they stop the clocks whenever they intervene. They do not adjudicate burned stones they did not see, because they are not expected to see them.
What umpires do enforce actively is sweeping. In officiated play, a first sweeping violation earns a warning to the whole team, and any subsequent violation by that team in the same event costs the stone. That escalation across an entire event, rather than a game, is a direct legacy of Broomgate.
Where local rules differ#
The World Curling rules apply to "any game or competition to which they are made applicable by the curling organisation having jurisdiction" — which is a polite way of saying your club can do what it likes.
In practice, the differences you will actually meet:
- Delivery sticks. Banned in World Curling competition outside wheelchair events; welcome in most clubs.
- Ends. Eight almost everywhere, ten only at the top.
- Clocks. Rare below national level. Most league games are timed by the lights going off.
- National variations. Curling Canada, for instance, publishes its own rules for domestic play, and has historically differed from the international ones — most famously by keeping a three-rock free guard zone until 2002.
Sources#
- Primary The Rules of Curling and Rules of Competition World Curling, 2025Everything on this page. Thinking time and the clock are C6; time-outs C7; measuring R12(d)–(f) and R2(i); touched and displaced stones R9 and R10; umpires C10 and the officiated-play definition in the glossary.
- How does the game clock work in curling? Olympics.comA plain-language version of the timing rules, useful if you are watching rather than playing.