🏛️Official — WCF
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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.
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, per Rule R2(i).; Eye on the Hog: Electronic sensor embedded...
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.
Under Rule R1(a), the length of the ice sheet from the inside edges of the back boards is a minimum of 45.720 m (150 ft), and the width from the inside edges of the side lines is a maximum of 4.750 m (15 ft 7 in). If an existing facility cannot ac...
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.
Rule R1(b) sets out the markings at each end of the sheet, drawn from side line to side line: Tee line: Maximum width 13 mm (1/2 in), placed so its centre is 17.375 m (57 ft) from the middle of the sheet.; Back line: Maximum width 13 mm (1/2 in), with its outside edge 1.829 m (6 ft) from the cent...
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.
Rule R1(d) provides that a centre hole (tee) is placed at the intersection of each tee line and centre line. With the tee as centre, there are four concentric circles at each end of the sheet: the outer circle has a radius of 1.829 m (6 ft, the 12...
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.
Under Rule R6(a), a stone that comes to rest between the tee line and the hog line at the playing end, excluding the house, is within the Free Guard Zone (FGZ). Stones resting in this zone are protected under the FGZ rule until the delivery of the sixth stone of the end (R6(b); 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.
Under Rule R3(a), a team is composed of four players, each delivering two stones in consecutive order in each end while alternating with an opponent.
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.
Under Rule R17(a), a Mixed Doubles team is composed of two players, one male and one female; alternates are not permitted, and a team must forfeit any game it fails to complete with both players participating for the entire game. Per R17(d), each team delivers 5 stones per end.
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 (see Rules of Competition, Section C10). Has authority to forfeit a game in cases of unsportsmanlike conduct or repeated time violations.; Deputy Chief Umpire: Assists the Chief Umpire and oversees ...
— Section C
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.
A standard game consists of 10 ends (8 ends in Mixed Doubles, per R17(c)). 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. Under Rule R5(a), unless predetermined or decided by the Last Stone Draw (LSD), teams use a coin toss to determine which team delivers the first stone of the first end; th...
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, governed by Rule R5: Starting position: The player places one foot in the hack and positions the stone on the ice ahead of the hack. Right-handed deliveries are made from the hack on the left of the centre line, and left-handed deliveries from th...
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. Under Rule R6(a)–(b), a stone that comes to rest between the hog line and the tee line at the playing end, excluding the house, is deemed to be within the FGZ.
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.
Power Play: Once per game, when it holds the decision on placement, a team may invoke the Power Play (not available in extra ends). The in-house stone (Position B) is moved to either side of the house, with its back edge on the tee line at the point where the 8-foot and 12-foot rings meet; the gu...
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.
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.
Under Rule R5(e), the delivering player must clearly release the stone from the hand before it reaches the near (delivery-end) hog line. If the stone is not released in time, it is immediately removed from play by the delivering team; if it is not...
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.
Rule R9 governs touched moving stones. Between the tee line at the delivery end and the hog line at the playing end, if a moving stone is touched by the team to which it belongs, or by their equipment, the touched stone is removed from play immedi...
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 before the delivery of the sixth stone of the end, the delivered stone is removed and the displaced FGZ stone is restored to its original position by the non-offending team; any other ...
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.
Rule R8(a) of the WCF's August 2026 Rules of Curling prohibits specific sweeping techniques: raising the brush head in front of a moving stone, depositing debris in front of a moving stone, or failing to finish a sweeping motion to the side of the...
Why people argue about this
People often think that they can sweep a stone by raising their broom head in front of it while it's moving, but actually, the rule states you're only allowed to move your brush side-to-side and finish each stroke behind the stone. The confusion arises because sweeping too close or directly at the stone is permitted as long as debris isn't deposited or brushing technique isn't used improperly.
If a player delivers a stone out of proper rotation, under Rule R5(j) the end continues as if the mistake had not occurred: the player who missed a turn delivers the last stone for that team in tha...
Why people argue about this
People often assume that if a player delivers a stone out of order in curling, their team automatically loses the end, which is incorrect. Actually, the confusion arises because under Rule R5(j), the game continues as if nothing happened, and it's up to the next eligible player on the team to deliver the last stone for that end.
A stone that completely crosses the outside edge of the back line at the playing end is removed from play immediately (R2(g)). A stone that touches a divider or a side line is removed from play immediately and prevented from entering an adjacent sheet (R2(h)).
Why people argue about this
People often think that if a stone barely touches the side line, it's still okay as long as it doesn't completely cross over. But actually, according to R2(h), any stone that even brushes against or touches the side line is removed from play immediately and can’t enter an adjacent sheet, regardless of how close they were to crossing.
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 thinking time is about how long they spend deciding their next move on the ice, which can be a few seconds. However, the 7.7 Time Violation actually refers to the time allowed for each end of play, not decision-making duration, and it's crucially enforced as a strict rule at WCF international events because any violation results in an immediate forfeit.
Illegal broom heads: Use of non-approved broom head material results in disqualification from the event.; Prohibited substances: Under Rule R18, use of performance-enhancing drugs without a therapeutic use exemption, whether taken knowingly or otherwise, is prohibited; violators are disqualified ...
Why people argue about this
People often assume that the material of their broom heads is allowed if they've never heard of a list of approved materials, leading to disputes at events. The confusion arises because the WCF does not provide a comprehensive list of approved broom head materials, leaving athletes and officials guessing about what's permissible.
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.
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.
Under Rule R1(a), the length of the ice sheet from the inside edges of the back boards is a minimum of 45.720 m (150 ft), and the width from the inside edges of the side lines is a maximum of 4.750 m (15 ft 7 in). If an existing facility cannot ac...
— 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.
Under Rule R3(a), a team is composed of four players, each delivering two stones in consecutive order in each end while alternating with an opponent.
— Section C
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, per R17(c)). 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.
Under Rule R5(e), the delivering player must clearly release the stone from the hand before it reaches the near (delivery-end) hog line. If the stone is not released in time, it is immediately removed from play by the delivering team; if it is not...
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.