Three-cushion is the purest test in carom billiards: score by driving your cue ball off at least three cushions and into both object balls. Here are the official UMB rules — the valid carom, scoring, fouls, the break and the match format.
The valid carom
You play with three balls on a pocketless table: your cue ball, your opponent's cue ball (the other white/yellow) and the red. Both whites and the red serve as object balls.
A valid three-cushion carom requires that, after you strike your cue ball, it:
- contacts both object balls, and
- touches at least three cushions before it reaches the second object ball.
The order is otherwise free: the cushions and the first object-ball contact may happen in any sequence, as long as three distinct cushion contacts are completed before the cue ball touches the second object ball. Hitting the same cushion more than once counts each time.
Scoring & innings
- Each valid carom scores 1 point.
- A player continues at the table as long as they keep scoring. A miss ends the turn — one turn is an inning.
- A player's average is points ÷ innings; 1.5+ is elite, the amateur target is around 0.5.
The opening break
To start, the balls are spotted: the red on the foot spot, the opponent's cue ball on the head spot, and the breaker's cue ball beside it (within a ball's width). The breaker must play the red ball first. A lag (banking to the near cushion) decides who breaks.
Fouls
A foul ends your turn and scores nothing; the balls stay where they stop (no penalty points in three-cushion). Common fouls:
- Failing to complete a valid carom.
- The cue ball or any ball leaving the table.
- Touching a ball with anything other than the cue tip.
- Double hit or push shot (tip stays on the cue ball).
- Shooting before all balls have stopped, or out of turn.
- Not having at least one foot on the floor.
- Time foul — exceeding the shot clock.
Match format
- UMB matches are played to a set number of points — typically 40, rising to 50 from the quarter-finals at major events.
- A shot clock (usually 40 seconds, with one time-out extension per visit) keeps play moving.
- The equal-innings rule gives the player who started second a final equalizing inning, so both have the same number of turns.
Equipment rules
Matches use a pocketless 2.84 m × 1.42 m heated table and three 61.5 mm balls (white, yellow, red). The full specifications — cue, balls, cloth and table — are in the equipment guide.
Other carom games
- Libre (free game): no cushion requirement — simply carom off both object balls. Restricted "balk" zones (corner boxes) stop endless nursing.
- Balkline (47/2, 71/2): the table is divided by lines; only a limited number of shots is allowed with both object balls inside a balk space.
- One-cushion: at least one cushion before the second object ball.
- Artistic billiards: a fixed program of set trick shots scored by difficulty.
Practise the rules free in 3ball
Reading the rules is one thing; feeling a three-cushion route is another. 3ball enforces the real carom rule with accurate physics, shows whether each shot is valid, and lets you replay classic positions free in your browser.