The Type of Game: International or "English" snooker is the most widely played form of snooker around the world. It is generally played on 6ft x12ft English billiard tables, with cushions that are more narrow than on pocket billiard tables and which curve smoothly into the pocket openings.
5ft x 10ft and snooker tables of even smaller playing dimensions may be used for the game.
On a 6ft x 12ft snooker (English billiard) table the playing area within the cushion faces shall measure 11ft 8.5in x 5ft 10in with a tolerance on both dimensions of +/-0.5in.
The height of the table is measured from the floor to the top of the cushion rail, and the height shall measure 34in with an allowable variance of +/-0.5in.
Balls Used: Set of Snooker balls: fifteen object balls that are not numbered and are solid red (called reds), six object balls of other colors that are not numbered (called colors) and a cue ball (called the white ball).
Point values for object balls: red-1, yellow-2, green-3, brown-4, blue-5, pink-6, black-7.
In International Snooker the balls used are 2-1/16in diameter.
The Rack: Play begins with the balls placed as in the diagram above. The pink is spotted on the Pyramid Spot. The apex ball of the triangle of reds is racked as close as possible to the pink without touching it.
Baulk-line and Baulk: A straight line drawn 29" from the face of the bottom cushion and parallel to it is called the Baulk-line and the intervening space termed the Baulk.
The Half Circle: The Half Circle is a semi-circle described in Baulk with its center at the middle of the Baulk-line and with a radius of 11.5in. When the striker has cue ball in hand within the Half Circle he may place the base of the cue ball anywhere on the line or within the Half Circle, and may use his hand or any part of his cue (including the
tip) to position the cue ball--as long as it is judged he is not attempting to play a stroke.
Object of the Game: To score a greater number of points than opponent.
Scoring: Points are scored in two ways: players are awarded points for fouls by the opponent (see Penalties For Fouls below), and by legally potting reds or colors. Each legally potted red ball has a point value of one; each legally potted color ball has a point value as indicated (Balls Used above). A frame ends when all balls have been potted, following the Rules of Play; if, however, only the black (7) ball is left on the table, the frame ends with the first score or foul.
If the players' scores are equal after that scoring, the black is spotted on its original position and the players lag or draw lots for the choice of playing at, or assigning opponent to play at, the black ball with the cue ball in hand within the Half Circle, first score or foul then ends the frame.
Opening Break: Players lag or draw lots for choice of break in the opening frame. In a match format the players alternate the break in subsequent frames. Starting player has cue ball in hand within the Half Circle. He must cause the cue ball to contact a red ball. It is not necessary to send a ball to a rail or into a pocket. Failure to meet this requirement is a foul (see Penalties For Fouls)
A foul is scored and - with all fouls - the incoming player has a choice of (1) accepting the table and becoming the striker, or (2) requiring the offender to break again.
Rules of Play
1. A legally potted ball entitles the striker to continue at the table until he fails to legally pot a ball.
2. On all shots, the striker must comply with the appropriate requirements of Rules of Play 5 and 6. It is not necessary to cause the cue ball or an object ball to contact a cushion or drop in a pocket after the cue ball has contacted a legal object ball (ball on). Failure to contact a legal object ball first is a foul.
3. As long as reds are on the table, the incoming striker (player taking his first stroke of an inning) always has a red as his legal object ball (ball on).
4. Any red balls potted on a legal shot are legally potted balls; the striker need not call any particular red ball(s), pocket(s) or details of how the pot will be played.
5. When the striker has a red ball as his "ball on" (legal object ball), he must cause the cue ball's first contact to be with a red ball. Failure to do so is a foul (See Penalties For Fouls)
6. After the striker has scored a red ball initially, his next legal object is a color, and as long as reds remain on the table he must alternate his play between reds and colors (though within each group he may play a ball of his choice). When reds remain on the table and a color is his object, the striker must (a) designate prior to stroking
which color ball is his object (that specific color is then his "ball on"), and (b) cause the cue ball's first contact with a ball to be with that colored ball. If the striker fails to meet these requirements, it is a foul (See Penalties For Fouls).
7. If the striker's ball on is a red, and he pots a color, it is a foul.
8. If the striker's ball on is a color, and he pots any other ball, it is a foul.
9. Jump shots are illegal in International Snooker. It is a foul if the striker intentionally causes the cue ball to jump (rise from the bed of the table) by any means, if the jump is an effort to clear an obstructing ball.
10. While reds remain on the table, each potted color is spotted prior to the next stroke (see Spotting Balls below for spotting rules). After a color has been spotted, if the striker plays while that ball is incorrectly spotted (and opponent or referee calls it before two such plays have been taken), the shot taken is a foul. If the striker plays
two strokes after such error without its being announced by opponent or referee, he is free of penalty and continues playing and scoring normally as though the spotting error simply had not occurred. The striker is responsible for ensuring that all balls are correctly spotted before striking. If the striker plays while a ball(s) that should be on
the table is not a foul may be awarded whenever the foul is discovered during the striker's inning. Any scoring prior to the discovery of the foul will count.
11. When no reds remain on the table, striker's balls on become the colors, in ascending numerical order (2,3,4,5,6,7). These legally potted colors are not spotted after each is potted; they remain off the table.
(The black (7) ball is an exception in the case of a tie score; see Scoring.)
Illegally Potted Ball: Reds illegally potted are not spotted; they remain off the table. Colors illegally potted are spotted. (See Spotting Balls)
Object Balls Jumped off the Table: Reds jumped off the table are not spotted and the striker has committed a foul. Colors jumped off the table are spotted and the striker has committed a foul. (See Penalties For Fouls)
Spotting Balls: Reds are never spotted. Colors to be spotted are placed as at the start of the game. If a color's spot is occupied (to mean that to spot it would make it touch a ball), it is placed on the spot of the highest value color that is unoccupied. If all spots are occupied, the color is spotted as close as possible to its original spot on a straight line between its spot and the nearest point on the top (foot) cushion.
Cue Ball after Jumping off the Table: Incoming player has cue ball in hand within the Half Circle. When cue ball is in hand within the Half Circle (except the opening break), there is no restriction (based on position of reds or colors) as to what balls may be played; striker may play at any ball on regardless of where it is on the table.
Touching a Ball: While balls are in play it is a foul if the striker touches any object ball or if the striker touches the cue ball with anything other than the tip during a legal stroke.
Snookered: The cue ball is snookered when a direct stroke in a straight line to any part of every ball on is obstructed by a ball or balls not on. If there is any one ball that is not so obstructed, the cue ball is not snookered. If in-hand within the Half Circle, the cue ball is snookered only if obstructed from all positions on or within the Half
Circle. If the cue ball is obstructed by more than one ball, the one nearest to the cue ball is the effective snookering ball.
Angled: The cue ball is angled when a direct stroke in a straight line to any part of every ball on is obstructed by a corner of the cushion. If there is any one ball on that is not so obstructed, the cue ball is not angled. If angled after a foul the referee or player will state "Angled Ball", and the striker has the choice to either (1) play from that position or (2) play from in hand within the Half Circle.
Occupied: A spot is said to be occupied if a ball cannot be placed on it without it’s touching another ball.
Touching Ball: If the cue ball is touching another ball which is, or can be, on, the referee or player shall state "Touching Ball." Thereafter the striker must play away from it or it is a push stroke (foul). No penalty is incurred for thus playing away if (1) the ball is not on; the ball is on and the striker nominates such ball; or (3) the ball is on
and the striker nominates, and first hits, another ball. [If the referee considers that a touching ball has moved through an agency other than the player, it is not a foul.]
Push Stroke: A push stroke is a foul and is made when the tip of the cue remains in contact with the cue ball (1) when the cue ball makes contact with the object ball, or (2) after the cue ball has commenced its forward motion. Provided that where the cue ball and an object ball are almost touching, it shall be deemed a legal stroke if the cue ball hits the finest possible edge of the object ball.
Miss: The striker shall to the best of his ability endeavor to hit the ball on. If the referee considers the rule infringed he shall call foul and a "miss." The incoming player (1) may play the ball(s) as they lie, or (2) may request that the ball(s) be returned to the original position and have the offending player play the stroke again. Note: if the ball
on cannot possibly be hit, the striker is judged to be attempting to hit the ball on.
Free Ball: After a foul, if the cue ball is snookered, the referee or player shall state "Free Ball." If the non-offending layer takes the next stroke he may nominate any ball as on. For this stroke, such ball shall be regarded as, and acquire the value of, the ball on. It is a foul should the cue ball fail to first hit, or - except when only the pink and black remain on the table - be snookered by, the free ball. If the "free ball" is potted, is is spotted, and the value of the ball on is scored. if the ball on is potted it is scored. If both the "free ball" and the ball on are potted, only the value of the ball on is scored.
If a foul is committed:
1. the player who committed the foul incurs the penalty prescribed (which is added to the opponent's score), and has to play again if requested by the next player. Once such a request has been made it cannot be withdrawn.
2. should more than one foul be committed in the same stroke the highest value penalty shall be incurred.
3. any ball improperly spotted shall remain where positioned, except that if off the table it shall be correctly spotted.
Penalties for Fouls
The following are fouls and incur a penalty of four points or the higher one prescribed:
1. value of the ball on - by striking:
a) when the balls are still moving from the previous shot.
b) the cue ball more than once (double hit).
c) without at least one foot on the floor.
d) out of turn.
e) improperly from in hand within the Half Circle.
f) the cue ball to miss all object balls.
g) the cue ball to enter a pocket.
h) a snooker with free ball.
i) a jump shot.
2. value of the ball on or ball concerned - by causing:
a) a ball not on to enter a pocket. b) the cue ball to first hit a ball not on. c) a push stroke. d) by striking with a ball not correctly spotted.
e) by touching a ball with other than the tip of the cue. f) by forcing a ball off the table.
3. value of the ball on or higher value of the two balls by causing the cue ball to hit simultaneously two balls other than two reds or a "free ball" and the ball on.
4. penalty of seven points is incurred if - the striker
a) after potting a red commits a foul before nominating a color.
b) uses a ball off the table for any purpose.
c) plays at reds in successive strokes.
d) uses as the cue ball any ball other than the white one.