The Sheet
The playing surface is called the sheet. A regulation sheet is 42.07 m (138 ft) long and 4.32 m (14 ft 2 in) wide. The ice is not smooth. It's covered in tiny rounded bumps called pebble, which reduce surface contact so the stone can glide and curl.
Knowing the zones and lines is essential to understanding every broadcast call and strategy discussion.
Key Lines
- Hack: the rubber foothold you push off from when delivering. There's one at each end.
- Hog line: a thick line roughly 10 m (33 ft) from the hack. You must release the stone before the near hog line, and the stone must cross the far hog line, or it's removed from play.
- Tee line: the line running through the centre of the rings at each end, perpendicular to the sheet.
- Back line: behind the rings. A stone that fully crosses the back line is removed.
- Centre line: runs the full length of the sheet down the middle.
The House
The house is the target. Two concentric rings painted on the ice at each end. Stones must be at least partially within the outer ring (touching or inside) to count in scoring.
- Button — the very centre dot. The bullseye.
- 4-foot ring — the innermost coloured ring surrounding the button.
- 8-foot ring — middle ring.
- 12-foot ring — outermost ring. A stone must be at least partially inside this ring to be in play for scoring.
The Guard Zone
The space between the far hog line and the front of the 12-foot ring, but not inside the house itself — is called the guard zone. Stones placed here act as shields. The first four stones of every end placed in this zone receive special protection (see Free Guard Zone).
Curling Ice uses exact WCF measurements for all sheet elements. Every ring, line, and hack is to scale. If you've stood on a real sheet, you'll recognize the geometry immediately.
The Rocks
Each Rock (also called a stone) weighs 19.1 kg (42 lbs) and is carved from dense granite. The bottom is hollow, only a narrow running band contacts the ice, which minimizes friction and allows the stone to travel a long distance from a relatively gentle push.
The handle on top is grasped during delivery and rotated at release to impart spin. That spin causes the stone to drift sideways as it slows, this drift is called curl.
Each team has 8 rocks per end, coloured differently from the opponent. 16 rocks total travel down the sheet each end.
Two rock sizes are available. Standard scale uses regulation dimensions relative to the sheet. The 2× size has larger stones that are easier to aim on a small phone screen — same physics, bigger tap target.
Delivery & Weight
Throwing a stone is called the delivery. You start in the hack, slide forward on the ice, and release the stone before it reaches the near hog line. The handle (turn) you apply at release determines which direction the stone curls.
In-turn vs. Out-turn
For a right-handed player: in-turn is a clockwise rotation at release. The rock curls to the right as it slows. Out-turn is counter-clockwise. The stone curls left. Left-handed players are mirror-image. In every end you choose which turn to use based on which path you need.
Weight
Weight is curling's word for how hard you throw, or how FAST the rock moves. In practice, how far the stone travels. Weight is the most fundamental skill in the sport. All strategy is built on the assumption that the throwing team can execute the right weight consistently.
Weight names run from slowest to fastest:
| Weight Name | Where it stops | Common use |
|---|---|---|
| Far Guard / Bumper | Just past the far hog line; well short of the house | Long guard to protect a stone deep in the house |
| Guard | Between the hog line and front of the house | Standard guard placement |
| Draw | Somewhere in the house, ideally the button | Scoring position; the bread-and-butter shot |
| Hack Weight | Dies near or at the far hack after impact | Controlled takeout that stays in or near the rings |
| Normal / Board Weight | Rolls to the back boards after a hit | Clean removal; shooter exits, cleared stone exits |
| Hit Weight | Through the house and well past | Hard takeout; less curl, straighter path |
| Peel Weight | The fastest. both stones exit the sheet | Removing a guard so no stones remain in the guard zone. 'peeling' them off the sheet into oblivion. |
Enable the Weight Hint in Settings to see your estimated weight zone during delivery. It's derived from your split time the pace of your swipe from back line to hog line — and maps directly to the names in the table above.
Sweeping
Two players on each team act as sweepers. They run alongside the stone and scrub the ice in front of it with brooms. It looks frantic; the effect is real and significant.
What Sweeping Does
Vigorous sweeping generates a small amount of heat that temporarily softens the pebble. This does two things:
- Reduces friction the stone travels further. A well-swept stone can travel 1–3 metres more than an unswept one.
- Reduces curl the path straightens. The stone still curls, but less.
This gives the team enormous real-time control over where a stone ends up. A shot that looks narrow can be swept wide; a short shot can be swept to reach the house. Sweeping decisions are called by the skip (or vice for the skip's shots).
Who Calls It
The skip watches the stone travel and calls "sweep!" when they want maximum effort, or "off!" (sometimes "whoa!") to stop. For the skip's own shots, the vice holds the broom and makes the calls.
In Curling Ice, sweeping reduces friction by up to 50% and cuts curl by up to 65% at maximum effort. Both values tunable in the Ice Physics settings. Swipe across the ice in front of the moving stone to sweep.
Ends & Scoring
How an End Is Played
A game is divided into ends (comparable to innings in baseball). In competitive play there are 8 or 10 ends. Each end, both teams alternate throwing their 8 stones — one at a time, starting with the lead. The order within a team is always lead (stones 1–2), second (3–4), vice (5–6), skip (7–8). The team with hammer throws last.
Scoring
After all 16 stones have been thrown, the end is scored. Only one team can score per end.
Count all the stones belonging to one team that are closer to the button than the nearest stone of the other team. Those stones score 1 point each. Stones must be at least partially within the 12-foot ring to count.
Example: Red has three stones in the house. Yellow has two. Yellow's closest stone is further from the button than Red's three closest stones. Red scores 3 that end.
Blank End
If no stones are in the house after measuring, or the teams cancel each other out, it's a blank end — no score. The team that had hammer keeps it for the next end. This is intentional: a team with hammer that can't score a good number sometimes chooses to blank rather than take one, preserving the hammer advantage.
Steal
When the team without hammer scores, it's called a steal. A steal is one of the most prized outcomes in curling — it scores points and takes hammer away from the opponent.
Positions on the Team
A curling team has four players, each with a defined role and throwing order.
Opens each end. Sets up guards, draws to scoring position early, or peels opponent guards. Sweeps for all teammates.
Builds on the lead's setup — adding guards, filling scoring positions, or making takeouts. Also sweeps.
A critical role. Holds the broom and calls sweeping for the lead and second. Discusses and agrees on the score at the end of each end. Calls sweeping for the skip's shots.
The captain. Holds the broom for lead, second, and vice shots. Calls the strategy and line. Throws the last two shots — including hammer if the team has it.
The Hammer
The hammer is the last stone of the end — the single most valuable positional advantage in curling. The skip who throws hammer has the final word on the position of stones. No opponent can respond.
Who Gets Hammer?
The team that did not score in the previous end receives hammer in the next one. If the end was blanked, the team that had hammer keeps it. This means the losing team is continuously rewarded with last-stone advantage — the game is self-correcting.
Why It Matters Strategically
Almost every strategic decision in a game flows from whether you have hammer:
- With hammer: you aim to score 2 or more. Scoring just 1 is often considered a failure ("forced to take one") because you give hammer to your opponent.
- Without hammer: you try to steal (score without hammer) or force the opponent to take only 1 — then you receive hammer next end having effectively won the exchange.
- Blanking: with hammer and no good scoring opportunity, blanking the end preserves hammer for a better end later.
The fastest way to understand hammer strategy is to play with it. After a few matches in Curling Ice you'll instinctively start blanking ends and appreciating steals in a way no article can fully convey.
Shot Types
Every shot in curling belongs to one of two families: draws (the stone stops somewhere useful) or takeouts (the stone removes another stone and usually exits). Within those families, dozens of named shots describe specific targets and outcomes.
A stone delivered to rest in or near the house. The most important shot in curling — everything else in the draw family is a variation of it.
A draw that stops in the guard zone (between the hog line and the house) to protect a stone sitting behind it. Guards force the opponent to work around them.
A draw that curves around an existing guard to rest behind it — protected from a straight-line takeout. Requires precise weight and ice reading.
A gentle hit on your own stone to nudge it back further in the house — typically to button position. Low weight, delicate execution.
Hitting your own stone (or a teammate's) to move it forward into a better scoring position. The shooter carries the raised stone deeper into the house.
A shot with enough weight to remove an opponent's stone. The shooter often rolls to a useful position after impact rather than exiting cleanly.
A takeout that removes the opponent's stone and then rolls the shooter to a strategic position — often hiding behind a guard or into scoring position.
A takeout that removes two or three opponent stones in one shot, usually by crashing the first stone into the second. High reward, higher risk.
A fast takeout of a guard — both the shooter and the guard exit the sheet. Used to open up a cluttered guard zone and force a draw game.
An extremely precise draw that stops touching, or nearly touching, an opponent's stone in the house — making it very hard to remove cleanly without also moving the freeze stone.
The Shots Catalog in Curling Ice documents all major shot types with diagrams and interactive scenarios you can run from inside the app.
The Free Guard Zone
The Free Guard Zone (FGZ) rule is modern curling's most strategically significant rule. It was introduced specifically to prevent teams from peeling every guard and producing low-scoring, boring games.
The Rule
The first four stones of each end cannot be removed from play if they come to rest in the guard zone — between the hog line and the outside edge of the rings, but not inside the house. If a team attempts to remove such a stone (with a takeout or peel), the violation is called: the thrown stone is removed, and the guard is replaced exactly where it was.
Strategic Impact
This changes everything. Teams can now build a guard game in the early stones of an end knowing those guards are protected. The team without hammer uses this to set up a come-around or freeze situation. The team with hammer must navigate around those guards rather than simply peeling them away.
The FGZ is the reason modern championship curling features complex early-end guard battles and why the game rewards strategic thinking so heavily.
Curling Ice enforces the FGZ rule in match mode. Violations are called automatically — the shooter is removed and the guard is replaced. This is the real rule; the game doesn't soften it.
Basic Strategy
Once you understand the positions, shots, and FGZ rule, the strategy flows naturally from one central question each end: do we have hammer?
Playing With Hammer
With hammer your goal is to score 2 or more. Start by drawing into the four-foot ring early. Protect that stone with a centre guard. Your opponent will try to remove your scoring stones; keep replacing them and adding guards. By the time you throw your last two stones, you want a partially open path to the button with scoring stones already in the house. Scoring 1 is acceptable only late in a close game where a blank would give your opponent hammer at a critical moment.
Playing Without Hammer
Without hammer you're trying to either steal (score) or force your opponent to take just 1. Set up centre guards immediately — the FGZ protects them. Try to get a stone around those guards and close to the button. Force the opponent to execute difficult shots. Even if you don't steal, forcing them to take 1 and receiving hammer next end is a winning exchange.
When to Blank
Blanking an end is not an accident — it's a strategic choice. If you have hammer but the end develops poorly (too many opponent stones, no clean path), deliberately throw the last stone through without scoring to keep hammer for a better setup next end.
Reading the Score
In the final ends, strategy shifts dramatically based on the score. A team down by 3 with two ends left must try for multi-point steals even at great risk. A team up by 2 with hammer in the last end will blank rather than score one and give the opponent a final-end steal attempt. Score awareness changes every shot decision.
Quick-Reference Glossary
Every term from this guide, alphabetically.