🏛️Official — WCF
Loading OpenSourceSports…
Call your own burned stone immediately
If a sweeper accidentally touches a moving stone with their broom, they are expected to call the infraction on themselves immediately rather than waiting for the opposing team to notice. Self-reporting fouls is central to curling's honor code and treated as one of the most fundamental obligations a player has.
Concede when mathematically eliminated
When a team cannot possibly win given the remaining ends and stone differential, the losing skip is expected to extend a handshake to concede rather than force the opposing team to play out meaningless ends. Refusing to concede in a clearly lost position is considered disrespectful and contrary to the spirit of the game.
Remain still and silent during a player's delivery
All players and bystanders should be quiet and motionless while a player is in the hack preparing to deliver. Talking, moving in the shooter's peripheral vision, or making distracting noise mid-delivery is a significant breach of etiquette regardless of which team is affected.
Pre-game and post-game handshake with 'good curling'
Teams shake hands with every member of the opposing team before the first end, exchanging the phrase 'good curling.' A second handshake follows the final end. This ritual is universally observed from recreational club leagues to the Olympics and frames every contest as one between respectful competitors.
Curling stones are made of dense, polished granite. The majority of competition stones are crafted from granite quarried on Ailsa Craig, a small volcanic island off the coast of Ayrshire, Scotland.
Why people argue about this
People often assume that all curling stones are made from granite quarried in Scotland, forgetting that Ailsa Craig is a small island off the coast, leading them to believe there's only one source of these stones. The reality is much more diverse with many countries producing their own granite for curling stones worldwide.
Key Fact: Curling stones are made of dense, polished granite sourced from Ailsa Craig and Trefor, Wales. Weight is between 17.24 kg to 19.96 kg including handle and bolt.
Why people argue about this
People often assume that curling stones are just regular granite rocks found anywhere, which leads them to misunderstand their unique composition and sourcing from Ailsa Craig in Scotland and Trefor in Wales. They overlook the specific criteria for density, weight, and manufacturing process detailed by the rule, leading to confusion about what constitutes a legal stone under WCF standards.
Purpose: Sweeping the ice surface ahead of a moving stone to influence its speed and trajectory.; Construction: Modern brooms use a carbon fibre or fibreglass shaft with a fabric pad head. Traditional corn brooms are rarely used in competition.; WCF Approval: All broom heads must comply with WCF ...
Why people argue about this
People often assume that brooms are essential for curling, a fundamental part of the game's strategy and execution. However, they misunderstand that the WCF’s official equipment guidelines specifically exclude brushes from their list of required items, leading to confusion about what is truly necessary for playing the sport.
Slider shoe: Worn on the sliding foot (left foot for right-handed deliverers). The sole is coated with Teflon or a similar low-friction material to allow a smooth glide during delivery.; Gripper shoe: Worn on the hack (push-off) foot. The sole features a high-traction rubber coating for grip on i...
Why people argue about this
People often assume that curling footwear is just regular shoes for safety reasons, forgetting that there's a specialized type of boot designed specifically for ice use in curling. They overlook the fact that these boots are crucial for maintaining balance and control on the slippery ice surface, which can lead to misunderstandings about why they're required.
Stopwatch: Used by the skip or vice-skip to time stone speed (split times between hog lines) for weight judgement.; Measuring device: Used by officials to determine which stone is closest to the tee when it cannot be determined visually.; Eye on the Hog: Electronic sensor embedded in the stone ha...
Why people argue about this
People often assume that the WCF's 2.4 Additional Equipment section covers all sorts of non-standard equipment like custom brooms or specialized clothing, which it clearly doesn't address. The confusion arises because they interpret "additional equipment" as anything not traditionally part of a curling set, forgetting that this specific rule is strictly about stones and their specifications.
Curling is played on a carefully prepared rectangular sheet of ice with the following dimensions: Length: 150 ft (45.72 m) from hack to hack.; Width: 15 ft 7 in (4.75 m) standard; maximum 16 ft 5 in (5.0 m).
Why people argue about this
People often assume that the exact dimensions of 45'6" x 178' are strictly adhered to across all curling rinks worldwide, but in reality, there's a bit more leeway and local variations can occur due to factors like climate and maintenance resources. The rule allows for some flexibility to accommodate different conditions without compromising the integrity of the game.
Played on a prepared ice sheet with specific markings.
Why people argue about this
People often assume that curling is played on a perfectly smooth ice surface with no markings at all, which leads them to misunderstand the importance of the "3.1 Venue Specifications" rule. In reality, this rule emphasizes the need for a prepared ice sheet with specific markings like hog lines and house circles to ensure fair play and consistent scoring across different venues.
Hack: A rubber foothold embedded in the ice at each end, from which players push off during delivery. The hack is positioned on the centre line, behind the back line.; Back line: A line drawn across the width of the sheet at each end, positioned 6 ft (1.83 m) behind the tee line. A stone that com...
Why people argue about this
People often assume that the four concentric rings forming the house in curling are solely for decorative purposes, which leads them to overlook their crucial role in determining scores. Actually, these rings delineate where the rocks (the ice skated discs) must land to score points, and they're a fundamental part of how teams calculate their game's outcome.
The house is the circular scoring area at each end of the sheet, consisting of four concentric rings: Button: The centre point (tee), marked by the intersection of the tee line and centre line.; 4-foot ring: 4 ft (1.22 m) diameter.; 8-foot ring: 8 ft (2.44 m) diameter.
Why people argue about this
People often assume that the rings in the house are merely decorative borders around the scoring area, forgetting their crucial role in determining points. However, these rings actually define where stones must be thrown for a point to count, creating a precise geometry that can lead to complex score calculations and disputes over whether a stone landed within the correct ring.
The ice surface is maintained at approximately −5°C (23°F). After being levelled flat, the ice is pebbled — fine water droplets are sprayed onto the surface and allowed to freeze, creating a textured finish of small bumps.
Why people argue about this
People often think that the pebbled surface is purely for aesthetic purposes, making it seem like a decorative touch rather than crucial for gameplay. However, the actual confusion arises because the texture of the ice surface significantly affects how stones glide and skid during play, impacting accuracy and strategy.
The Free Guard Zone (FGZ) is the area between the hog line and the tee line, excluding the house itself. Stones resting in this zone during the first five deliveries of an end are protected under the Free Guard Zone rule (see Section 5).
— Section 5
Why people argue about this
People often assume that stones in the Free Guard Zone are only protected if they're touching the house at the start of play, but actually, any stone resting there during the first five deliveries is safeguarded, regardless of whether it's near the house or not.
Teams of 4 players: Lead, Second, Third (Vice-Skip), and Skip. Mixed Doubles: 2 players per team.
Why people argue about this
People often assume that mixed doubles curling teams can have more than two players since they see singles and triples formats in other sports. However, under WCF rules, mixed doubles must stick to a standard of just two players per team, with one male and one female player serving as Lead and Second respectively, while the Skip remains unchanged from traditional four-person teams.
A standard curling team consists of four players, each with a designated role and throwing order: Lead: Throws the first two stones for the team. Typically responsible for placing guards and early draws. Sweeps for all other teammates.; Second: Throws stones three and four. Often plays takeouts o...
Why people argue about this
People often assume that in Mixed Doubles curling, both team members must deliver exactly 5 stones each throughout the entire game of 8 ends, which they mistakenly believe is a requirement for winning. However, this isn't true; teams can distribute their stone deliveries however they choose as long as each player gets to throw at least one stone per end.
In Mixed Doubles, each team consists of one male and one female player. Each player delivers 5 stones per end (10 total per team across an 8-end game).
Why people argue about this
People often assume that mixed doubles curling teams can switch genders between games, thinking it's a gender-neutral format where either partner could be male or female each time. But actually, the WCF rules clearly state each team must have one man and one woman throughout the entire competition, with no flexibility in who plays which position based on game results.
Chief Umpire: The senior official responsible for final rule interpretation and dispute resolution. Has authority to forfeit a game in cases of unsportsmanlike conduct or repeated time violations.; Deputy Chief Umpire: Assists the Chief Umpire and oversees assigned sheets.; Game Umpires: Assigned...
Why people argue about this
People often assume that coaches can only whisper instructions to players during timeouts, which they believe is too restrictive. In reality, the rule explicitly states no communication is allowed during live play or on the ice surface, leading to confusion about what exactly constitutes "live play.
Each team may have a designated coach who can communicate with players only during timeouts and between ends. Coaches are not permitted on the ice surface or in the field of play during live play.
Why people argue about this
People often assume that coaches are only banned from the ice during timeouts because they believe it's about preventing them from giving live instructions. However, the real issue is actually keeping them out of harm’s way; coaches can get injured by pucks or rocks if they're not careful, and this rule aims to protect their safety rather than restrict their communication methods.
Free Guard Zone (FGZ): the first 5 stones of each end (3 per team in alternation) that come to rest in the FGZ (between hog line and tee line, excluding the house) may not be removed by the opposing team. Violation: removed stone is replaced, offending stone removed.
Why people argue about this
People often assume that if a stone is touching the edge of the Free Guard Zone (FGZ), it can be removed by the opponent team. However, the actual rule states that only stones that have already come to rest completely within the FGZ cannot be moved; stones partially in or on the edge are not affected. This distinction often leads to confusion and disputes during matches.
A standard game consists of 10 ends (8 ends in Mixed Doubles). Each end is analogous to an inning in baseball: both teams deliver all their stones, and then the end is scored.
Why people argue about this
People often assume that each end of a curling game is like one inning in baseball, where only one team gets to throw all their stones. But actually, both teams have an equal turn to deliver all their stones per end, making it more akin to a full cycle of play rather than just the batting side's turn.
The team that delivers the last stone in an end is said to have the hammer. This is a significant strategic advantage.
Why people argue about this
People often assume that having the hammer is just about who throws last, but they overlook how it fundamentally changes gameplay - teams with the hammer can strategically place their final stone in advantageous positions, forcing opponents to guess where to position theirs, creating a dynamic imbalance.
The delivery is the fundamental action in curling: Starting position: The player places one foot in the hack and positions the stone on the ice ahead of the hack.; Backswing and slide: The player draws the stone back, then pushes forward from the hack into a gliding lunge, sliding along the ice o...
Why people argue about this
People often assume that the "5.3 Stone Delivery" is just about how you slide the stone down the ice, but actually it encompasses all aspects of delivering the stone, including grip, release, follow-through, and even the angle at which you deliver it to ensure proper curling action. It's more than a physical motion; it's a strategic decision that can affect the entire game.
Sweeping is a critical skill that allows players to influence a stone's speed and trajectory after release: Mechanics: Sweepers vigorously brush the ice surface directly in front of the moving stone. This friction heats the pebble, creating a thin film of water that reduces friction between the s...
Why people argue about this
People often assume that sweeping is just about making a stone glide smoothly across the ice without realizing its true purpose: to control the speed and direction of the stone after it's released from the player's broom. They mistakenly believe it’s merely an aesthetic or maintenance task, but in reality, it's a strategic element crucial for scoring points.
The Free Guard Zone (FGZ) rule is one of the most important strategic rules in modern curling. During the first 5 stones of each end (the first 5 delivered stones, regardless of team), any stone that comes to rest in the Free Guard Zone (between t...
Why people argue about this
People often think that only their team's stones can be in the Free Guard Zone (FGZ), but in reality, both teams' stones are allowed there as long as they're legal throws. The confusion arises because players and coaches sometimes misinterpret the rule to mean it must always be empty for their team’s advantage.
Pre-placed stones: Before each end, one stone per team is pre-positioned — one as a guard in the centre line at the Free Guard Zone, and one in the back of the 8-foot ring on the centre line.; Power Play: Each team may use a Power Play once per game (not in extra ends). When invoked, the pre-plac...
Why people argue about this
People often assume that the thinking time clocks are meant for players to rest between their shots, when in reality they're there to ensure both teams have a fair amount of time to strategize and decide their next move, helping maintain game flow without letting one team dominate with longer decision times.
Draw: A stone delivered to come to rest at a specific location, typically in the house.; Guard: A stone placed in front of the house to protect a scoring stone behind it.; Takeout: A stone delivered with enough weight to remove an opponent's stone from play.
Why people argue about this
People often assume that the thinking time clocks are meant for players to strategize their shots more freely, essentially giving them an extended period to think without a strict limit. However, the actual purpose is to ensure fair play by keeping each team's decision-making process within a controlled timeframe, preventing any unfair advantage through prolonged deliberation.
At WCF international events, thinking time clocks are used to manage the pace of play.
Why people argue about this
People often assume that thinking time clocks in curling are for players to nap during their turn, which is incorrect. Actually, these clocks ensure each team has a set amount of time to plan their shots, reducing delays and speeding up gameplay without compromising strategy or fairness.
After all 16 stones (10 in Mixed Doubles) have been delivered in an end, the vice-skips from each team jointly determine the score. Only one team can score per end.
Why people argue about this
People often assume that if their team has more stones closer to the house at the end of an end than their opponent's, they automatically get all the points for scoring in that end. But actually, it’s about whose vice-skip judges which stones are valid and worth points based on distance from the center circle, not just counting how many they have.
After all 16 stones are delivered in an end, the team with the stone closest to the tee (center) scores. That team scores one point for each stone closer to the tee than the opponent's closest stone.
Why people argue about this
People often assume that if their stone is closer to the tee than their opponent's, they automatically score a point for each additional inch of distance, but actually, it's just one point awarded for being closer overall—no matter how much further ahead your stone is from the opponent’s. The exact measurement isn’t what counts; it’s who has the closest stone at the end.
A stone must be touching or within the 12-foot ring (the outermost circle of the house) to be eligible for scoring. The ring lines themselves are part of the house.
Why people argue about this
People often assume that as long as a stone is touching the 12-foot ring (outer circle), it's automatically in play for scoring. But actually, the lines of the 12-foot ring are part of the house and can't be used to determine eligibility; only stones touching or within this area are considered eligible for points.
If no stones from either team are in the house at the conclusion of an end, the end is blanked (no score is recorded). The team that had the hammer retains it for the next end.
Why people argue about this
People often assume that if no stones from either team are in the house at the end of an end, it means they get a point for having the hammer, which is incorrect. Actually, the key misunderstanding here is thinking that just because neither side has scored doesn't mean you keep the hammer; rather, the end is blanked entirely, and the team with the hammer goes first in the next end regardless.
If the score is tied after the regulation number of ends (10 or 8), extra ends are played until one team leads at the conclusion of an end. Each team receives 4 minutes 30 seconds of additional thinking time per extra end.
Why people argue about this
People often assume that extra ends are only for scoring purposes, thinking they'll just play out until someone wins by a single point. But actually, it's about maintaining fairness with equal thinking time, so teams get 4 minutes and 30 seconds per end regardless of how many more they have to play.
A team may concede the game at any point by offering a handshake to the opposing skip. Concession typically occurs when the score deficit is too large to overcome in the remaining ends.
Why people argue about this
People often assume that conceding is only about score deficit, thinking it's a binary decision based on how close they are to winning. But actually, it can happen at any point in the game when either team feels their efforts won't change the outcome significantly enough for them to risk losing by default if they don’t concede.
The delivering player must release the stone before it reaches the near (delivery-end) hog line. If the stone is not released in time, it is removed from play.
Why people argue about this
People often argue that they can't release their stone before it hits the hog line if doing so would be a foul. But actually, the key point is about when the stone must be released - not necessarily where it's released from. The rule emphasizes timing over position, leading to misunderstandings.
Key Fact: Hog Line Violation - If a stone touches near hog line, delivering player must release before reaching it. Verdict: Infraction results in removal from play if not released in time; Eye on the Hog system detects violations automatically.
Why people argue about this
People often assume that if a stone barely brushes near the hog line, it's automatically an infraction, forgetting that the delivering player must release before reaching it. They miss understanding that only if they don't manage to do so in time does it result in removal from play, not just brushing against the line itself.
If a moving stone is touched by a player, their equipment, or their clothing, it is considered a burned stone. The Spirit of Curling requires the offending team to immediately declare the infraction.
Why people argue about this
People often assume that touching a moving stone is just a minor infraction like in other sports, forgetting that in curling, it's considered a "burned stone" which means the whole play is nullified and they must start over from the beginning. They overlook how crucial maintaining the flow of the game is for teams playing against time constraints.
If a team removes an opponent's stone from the Free Guard Zone during the protected period (first 5 delivered stones per end, or first 3 in Mixed Doubles), the delivered stone is removed and the displaced FGZ stone is restored to its original position. All other affected stones are also restored.
Why people argue about this
People often assume that if a stone is removed from the Free Guard Zone (FGZ) by mistake during an end, it can simply be put back in place without affecting other stones. However, the rule stipulates that all affected stones must be restored to their original positions, not just the one mistakenly moved. This oversight leads to confusion about which stones need to be adjusted and how many.
If a player delivers a stone out of the designated rotation order and the error is noticed before the next stone is delivered, the stone is removed and redelivered by the correct player. If the error is not noticed until after the next delivery, p...
Why people argue about this
People often assume that if they notice the error after the next stone is delivered, it's too late to correct it, but actually, as long as the mistake is spotted before the subsequent player's turn, the offending stone can still be removed and redelivered by the right person. The confusion arises because the timing of noticing the error affects whether a correction can be made.
A stone that completely crosses the back line or touches the side line (or boards) is immediately removed from play. A stone that comes to rest between the hog lines without reaching the far hog line is also removed (unless it has contacted a stone already in play).
Why people argue about this
People often think that if a stone barely touches the back line or side lines, it stays in play as long as it hasn't hit another stone. But actually, the rule states that any stone touching either boundary is removed from play unless it has already contacted a stone already on the ice, which could be considered part of its trajectory.
If a team's thinking time expires on the game clock, the team forfeits the game. This is strictly enforced at WCF international events.
Why people argue about this
People often assume that a time violation means they've been playing too slowly, when in reality it's about waiting for their opponent to start play after throwing an stone. The confusion arises because they misinterpret "thinking time" as how long they spend deliberating on each shot, not the wait period between shots where both sides are ready and just need the clock to tick down.
Illegal broom heads: Use of non-approved broom head material results in disqualification from the event.; Unsportsmanlike conduct: Deliberate interference, abusive language, or repeated refusal to comply with officials' instructions may result in forfeiture of the game or expulsion from the compe...
Why people argue about this
People often assume that a green light means the stone was released at exactly the right time, which can lead them to overlook the fact that even if it's green, touching the hog line before release still disqualifies the stone, unlike in other sports where timing is more forgiving.
Footwear: All players and officials must wear clean, appropriate curling footwear. Slider guards must be worn when not delivering to prevent accidental falls.; No running: Running on the ice surface is strictly prohibited. Players must walk carefully, especially when moving between ends.; Awarene...
Why people argue about this
People often assume that warming up is only for preventing injury during a game, forgetting its importance in preparing muscles specifically for demanding movements like the deep lunge required for stone delivery. They overlook how core strength, particularly in the lower body and shoulders, plays a crucial role in safely executing this technique to avoid strain injuries.
Clean footwear required to prevent falls. Ice surface maintained between games.
Why people argue about this
People often assume that the 'clean footwear' requirement in curling is solely about hygiene, forgetting that it's crucial for preventing falls on the ice, which could be dangerous during a slippery game. The confusion arises because they overlook how clean shoes help athletes maintain their balance and control on the moving surface between games.
Brooms: Brooms must not be thrown, slammed, or used in any manner that could damage the ice surface or endanger other players.; Stones: Players must not drop or kick stones. Stones should be placed gently on the ice when being positioned.; Stabiliser devices: Players using delivery sticks or stab...
Why people argue about this
People often assume that warming up is just for preventing injury, forgetting its role in improving performance and technique. Thus, they might overlook how proper warm-up exercises can actually enhance their ability to perform a deep lunge effectively and safely, reducing strain on their hips, knees, and quads during the crucial stone delivery phase of the game.
Ice maintenance: The ice surface must be properly maintained between games, including re-pebbling and temperature monitoring. Deteriorated ice with excessive frost, uneven pebble, or pooling water must be addressed before play resumes.; Ventilation: Curling facilities must maintain adequate venti...
Why people argue about this
People often assume that warm-up exercises are optional for curlers because they believe their physical conditioning will suffice without additional preparation. However, the deep lunge required in stone delivery does place significant strain on lower body muscles, and a proper warm-up is crucial to prevent injuries like pulled quadriceps or strained hips and knees.
Players should perform appropriate warm-up exercises before taking the ice, particularly for the lower body, core, and shoulders. The deep lunge required for stone delivery places significant strain on the hips, knees, and quadriceps.
Why people argue about this
People often assume that warming up is only about loosening muscles before a game starts, forgetting its importance in preparing for specific movements like the deep lunge required in curling stone delivery. They overlook how crucial it is to condition their lower body and core specifically for such intense physical demands without injury risks.
Curling stones are made of dense, polished granite. The majority of competition stones are crafted from granite quarried on Ailsa Craig, a small volcanic island off the coast of Ayrshire, Scotland.
Why people argue about this
People often assume that all curling stones are made from Ailsa Craig granite simply because it's mentioned in the official rules, but actually, while most competition stones do come from there, other high-quality granite sources exist as well, making this a general guideline rather than an absolute rule.
Curling is played on a carefully prepared rectangular sheet of ice with the following dimensions: Length: 150 ft (45.72 m) from hack to hack.; Width: 15 ft 7 in (4.75 m) standard; maximum 16 ft 5 in (5.0 m).; Hack: A rubber foothold embedded in the ice at each end, from which players push off dur...
— Section 5
Why people argue about this
People often assume that the exact dimensions of 152 cm (60 inches) for each end of the playing area are strictly adhered to without room for variation, but in reality, there's a bit more flexibility allowed by the WCF. The rule states "carefully prepared," which allows some leeway in how precisely those dimensions can be achieved and maintained throughout the game.
A standard curling team consists of four players, each with a designated role and throwing order: Lead: Throws the first two stones for the team. Typically responsible for placing guards and early draws. Sweeps for all other teammates.; Second: Throws stones three and four. Often plays takeouts o...
Why people argue about this
People often assume that each team only gets 5 stones per end in total across all ends of an 8-end game, thinking it's a fixed limit for both teams combined. But actually, this is per player; each female player delivers 5 stones (as does the male player), making it 10 stones per team, not 5.
A standard game consists of 10 ends (8 ends in Mixed Doubles). Each end is analogous to an inning in baseball: both teams deliver all their stones, and then the end is scored.
Why people argue about this
People often assume that each end in curling is like a full game of baseball with 9 innings, forgetting that an end ends once all stones are thrown for both teams, regardless of score. The confusion arises because they mix up the concept of "ends" as scoring periods versus individual throws by players.
After all 16 stones (10 in Mixed Doubles) have been delivered in an end, the vice-skips from each team jointly determine the score. Only one team can score per end.
Why people argue about this
People often assume that both teams get to argue about which stones count for score, but in fact, only one team scores per end based on the vice-skips' decision, leading to disagreements over whose points are valid even when they've been correctly counted by the scorer.
The delivering player must release the stone before it reaches the near (delivery-end) hog line. If the stone is not released in time, it is removed from play.
Why people argue about this
People often assume that if their stone barely clears the hog line before stopping, it's still in play as long as they were aiming for a valid shot. But actually, the rule strictly states that the delivering player must release the stone well before it reaches the hog line; otherwise, it gets removed from play, regardless of where it stops afterward.
Players should perform appropriate warm-up exercises before taking the ice, particularly for the lower body, core, and shoulders. The deep lunge required for stone delivery places significant strain on the hips, knees, and quadriceps.
Why people argue about this
People often assume that warming up is only about physical fitness, forgetting its crucial role in preventing injuries like those from deep lunges required for stone delivery. They overlook how proper warm-up exercises can significantly reduce strain on key areas like hips, knees, and quadriceps, leading to misunderstandings about the necessity of such pre-game preparation.