the pool

Pool, also more formally known as pocket billiards (mostly in North America) or pool billiards(mostly in Europe and Australia), is the family of cue sports and games played on a pool table having six receptacles called pockets along the rails, into which balls are deposited as the main goal of play. Popular versions include eight ball and nine ball. An obsolete term for pool is six pocket.

There are hundreds of pool games. Some of the more well known include eight ball, nine ball, ten ball, straight pool, one pocket and bank pool.
There are also hybrid games combining aspects of both pool and carom billiards, such as American four ball billiards, cowboy pool and bottle pool.

1 Eight ball

2 Nine ball

3 Three ball

4 One pocket

5 Bank pool

The following General Rules apply to all the games covered by these rules except when contradicted by specific game rules. In addition, the Regulations of Pool Billiards cover aspects of the game not directly related to the game rules, such as equipment specifications and organization of events.
The games of Pool Billiards are played on a flat table covered with cloth and bounded by rubber cushions. The player uses a stick (pool cue) to strike a cue ball which in turn strikes object balls. The goal is to drive object balls into six pockets located at the cushion boundary. The games vary according to which balls are legal targets and the requirements to win a match.

It is the players responsibility to be aware of all rules, regulations and schedules applying to competition. While tournament officials will make every reasonable effort to have such information readily available to all players as appropriate, the ultimate responsibility rests with the player.

The lag is the first shot of the match and determines order of play. The player who wins the lag chooses who will shoot first.
The referee will place a ball on each side of the table behind the head string and near the head string. The players will shoot at about the same time to make each ball contact the foot cushion with the goal of returning the ball closer to the head cushion than the opponent.

A lag shot is bad and cannot win if the shooter?s ball:

(a) crosses the long string;
(b) contacts the foot cushion other than once;
(c) is pocketed or driven off the table;
(d) touches the side cushion; or
(e) the ball rests within the corner pocket and past the nose of the head cushion.
In addition, a lag will be bad if any non object ball foul occurs other than 6.9 Balls Still Moving.

The players will lag again if:

(a) a player?s ball is struck after the other ball has touched the foot cushion;
(b) the referee cannot determine which ball has stopped closer to the head cushion; or
(c) both lags are bad.

The equipment must meet existing WPA equipment specifications. In general, players are not permitted to introduce novel equipment into the game. The following uses, among others, are considered normal. If the player is uncertain about a particular use of equipment, he should discuss it with the tournament management prior to the start of play. The equipment must be used only for the purpose or in the manner that the equipment was intended.
(a) Cue Stick ? The player is permitted to switch between cue sticks during the match, such as break, jump and normal cues. He may use either a built in extender or an add on extender to increase the length of the stick.
(b) Chalk ? The player may apply chalk to his tip to prevent miscues, and may use his own chalk, provided its color is compatible with the cloth.
(c) Mechanical Bridges ? The player may use up to two mechanical bridges to support the cue stick during the shot. The configuration of the bridges is up to the player. He may use his own bridge if it is similar to standard bridges.
(d) Gloves ? The player may use gloves to improve the grip and/or bridge hand function.
(e) Powder ? A player is allowed to use powder in a reasonable amount as determined by the referee.

Balls are spotted by placing them on the long string as close as possible to the foot spot and between the foot spot and the foot rail, without moving any interfering ball. If the spotted ball cannot be placed on the foot spot, it should be placed in contact (if possible) with the corresponding interfering ball. However, when the cue ball is next to the spotted ball, the spotted ball should not be placed in contact with the cue ball; a small separation must be maintained. If all of the long string below the foot spot is blocked by other balls, the ball is spotted above the foot spot, and as close as possible to the foot spot.

When the cue ball is in hand, the shooter may place the cue ball anywhere on the playing surface and may continue to move the cue ball until he executes a shot. Players may use any part of the cue stick to move the cue ball, including the tip, but not with a forward stroke motion. In some games and for most break shots, placement of the cue ball may be restricted to the area behind the head string depending on the rules of the game, and then 6.10 Bad Cue Ball Placement and 6.11 Bad Play from Behind the Head String may apply.
When the shooter has the cue ball in hand behind the head string and all the legal object balls are behind the head string, he may request the legal object ball nearest the head string to be spotted. If two or more balls are equal distance from the head string, the shooter may designate which of the equidistant balls is to be spotted. An object ball that rests exactly on the head string is playable.

In games in which the shooter is required to call shots, the intended ball and pocket must be indicated for each shot if they are not obvious. Details of the shot, such as cushions struck or other balls contacted or pocketed are irrelevant. Only one ball may be called on each shot.
For a called shot to count, the referee must be satisfied that the intended shot was made, so if there is any chance of confusion, e.g. with bank, combination and similar shots, the shooter should indicate the ball and pocket. If the referee or opponent is unsure of the shot to be played, he may ask for a call.
In call shot games, the shooter may choose to call ?safety? instead of a ball and pocket, and then play passes to the opponent at the end of the shot. Whether balls are being spotted after safeties depends on the rules of the particular game.

A ball may settle slightly after it appears to have stopped, possibly due to slight imperfections in the ball or the table. Unless this causes a ball to fall into a pocket, it is considered a normal hazard of play, and the ball will not be moved back. If a ball falls into a pocket as the result of such settling, it is restored as closely as possible to its original position. If a settling ball falls into a pocket during or just prior to a shot, and this has an effect on the shot, the referee will restore the position and the shot will be replayed. The shooter is not penalized for shooting while a ball is settling.