Curling is played by two teams of four on a rectangular strip of ice called a sheet. Each team delivers eight stones per end, alternating with the opposition, toward a set of concentric rings called the house. When all sixteen stones have been thrown, one team scores: one point for every stone it has closer to the centre of the house than the opponent's nearest stone. The other team scores nothing. Repeat ten times and the higher total wins.
Two things make this harder than it sounds. The stone rotates as it is released and therefore curves, or curls, roughly a metre over its journey, so almost every shot is played on an arc around other stones. And the ice is not flat in the way a table is flat: it is sprayed with droplets that freeze into a texture called pebble, which wears down as the game goes on and changes how far and how much every stone travels. Teams sweep in front of a moving stone to manage exactly that.
Scoring at a glance
Core rules
The sheet and the house
A championship sheet is 45.72 metres long and up to 5 metres wide, with a house at each end made of concentric rings 12, 8 and 4 feet in diameter around a central button. The tee line runs through the centre of each house, the back line marks the far edge beyond which a stone is out of play, and the hog line sits 21 feet in front of the tee line, giving 72 feet of open ice between the two hog lines. Behind each house are the hacks, the footholds from which stones are delivered.
Delivering a stone
The thrower settles into the hack, pushes forward while sliding on a slippery-soled shoe, and releases the stone with a gentle rotation, two or three turns over its whole journey, which makes it curl. The release must happen before the hand crosses the near hog line; at elite level this is policed by handles with electronic sensors that light up if the stone is still held. A delivered stone must also cross the far hog line to stay in play, and must come to rest short of the back line.
Sweeping
Two sweepers may brush the ice in front of a running stone, briefly melting the pebble to reduce friction. Good sweeping can carry a stone several metres further than it would otherwise travel and straighten its path, so it is the main way a team corrects a shot that has been thrown slightly light or slightly wide. Only the throwing team may sweep its own stone between the tee lines; behind the far tee line one opposition player, usually the skip, may sweep it too.
Scoring an end
Once all sixteen stones are thrown, the team with the stone nearest the button scores, and keeps scoring for every additional stone it has closer than the opponent's best. Only stones touching the house count. Measurements are taken with a calibrated measuring stick when the eye cannot separate two stones. The team that scores throws first in the next end, which means scoring costs you last-stone advantage: the hammer always passes to the team that did not score.
The hammer
The hammer is the last stone of an end, and it is the single most valuable asset in the game because it lets a team react to everything the opposition has already done. It is awarded at the start of a game by the last stone draw, a pre-game shot in which each team draws to the button and the closer average wins. Thereafter it moves with the score. If an end is blanked, with nobody scoring, the hammer stays where it is, which is why a team with the hammer will often deliberately blank rather than take a single point.
The free guard zone
Stones that come to rest short of the house but past the hog line sit in the free guard zone. Under the five-rock rule, adopted by World Curling for the 2018-19 season, the first five stones of an end cannot be removed from play if they are in that zone; touching one and knocking it out means the thrown stone is removed and everything is put back. The rule exists to stop the stronger team simply clearing the ice, and it forces cluttered, high-scoring ends.
Order of play and roles
The lead throws the first two stones and is usually the team's best guard and draw specialist, plus a full-time sweeper. The second throws the next two and does the heaviest hitting and sweeping. The third, or vice-skip, throws stones five and six and holds the broom for the skip. The skip throws the last two, calls every shot from the house, and agrees the final score with the opposing vice-skip. Any player can be designated the skip without throwing last, an arrangement several elite teams now use.
Time, extra ends and conceding
Championship curling is played on thinking time: each team gets 38 minutes for a ten-end game, its clock running only while it decides and delivers. Running out of time loses the game. If the score is tied after the scheduled ends, teams play extra ends until somebody scores, with the hammer determined by the last end played. Concession is normal and expected: a team that believes it cannot win shakes hands, and games routinely end after eight or nine ends.
Fouls & penalties
Hog line violation
If the thrower has not released the handle before it reaches the near hog line, the stone is removed from play immediately. At world and Olympic level the call is made by an electronic handle, first used at the world championships in the mid-2000s, which reads the thrower's hand and shows a green or red light on the stone. At club level it is a judgement call, usually made honestly by the thrower without any prompting.
Burned stone
Touching a stone while it is running, with a brush, a foot or clothing, is called burning it. Convention rather than the umpire governs the remedy: if the touch happened before the stone reached the tee line, the non-offending skip may remove it; after the tee line, the skip may place all affected stones where they would have finished. Players are expected to declare their own burns, and doing so is one of the sport's strongest social norms.
Displaced stationary stones
If a stationary stone is knocked out of position by a player rather than by a thrown stone, it is put back where it was. If a running stone is then affected by that displacement, the non-offending team chooses whether to remove the thrown stone and reset everything, or to leave the result as it lies, or to place all stones where they judge they would have come to rest. The choice always belongs to the team that did not cause it.
Free guard zone infraction
Removing a protected guard from play before five stones have been delivered is the most common tactical infraction. The penalty is complete restoration: the delivered stone is taken off, the guard goes back where it was, and any other stone moved is replaced. Since 2023-24 the related no-tick rule has gone further at international events, protecting a centre guard from being nudged sideways as well as from being removed outright.
Sweeping infractions
Sweeping the wrong stone, sweeping an opponent's stone before it crosses the tee line, or brushing an opponent's stone behind the tee line when they have not finished sweeping it are all infractions, penalised by removal of the offending team's stone or by replacement of the affected one. Equipment is regulated too: since 2016 only a single approved brush-head fabric may be used in sanctioned events, a direct product of the Broomgate dispute.
Time expiry
A team that exhausts its thinking time loses the game on the spot, regardless of the score. The clock stops while stones are travelling and while the ice is being cleared, and starts again once the previous shot is complete, so the penalty falls squarely on indecision rather than on slow delivery. In tightly refereed events, running low on time visibly changes strategy: teams stop debating marginal options and take the simple shot.
Match format
Elite four-player events are round robins followed by playoffs. The world championships run a thirteen-team round robin over nine days, with the top six advancing to qualification games, semifinals and a final. The Olympic tournament uses ten teams in a single round robin, then semifinals, a bronze game and a final. National championships such as Canada's Brier and Scotties Tournament of Hearts use pools and a page playoff, a bracket that gives the top two seeds a second chance.
Mixed doubles is a separate discipline with its own world championship since 2008 and Olympic status since 2018. Two players, one of each gender, deliver five stones per team over eight ends, with one stone of each colour pre-placed before every end, giving six in play. One player throws the first and last stone, the other the middle three. Once per game each team may use a power play, shifting the pre-placed stones to one side of the sheet to open up scoring.
Keep exploring
More in this category
Golf
A six-century test of nerve where the only opponent is the ground, the wind, and yourself.
🎯Darts
A sport played on a target the size of a dinner plate, where the arithmetic never stops and the last dart is always the hardest.
🎱Snooker
Twenty-two balls, six pockets barely wider than they are, and the most pitiless scoreboard in sport.