The basic rules of pool depend on the particular pool discipline, so there is no single universal rulebook covering every game called pool. Eight ball, nine ball, ten ball, straight pool and English pool have different objectives, ball arrangements and foul procedures. Nevertheless, most pool games share a common framework. Players use a cue to strike a cue ball, which must then contact object balls and, in many situations, result in a legally pocketed ball or a legal defensive outcome.
The balls are normally arranged in a rack before the opening break. Players alternate visits to the table, and a successful legal scoring shot generally allows the same player to continue. A foul normally ends the player's visit and gives the opponent a defined advantage, often ball in hand. The precise meaning of a legal shot must always be interpreted under the rules of the specific discipline.
The opening break is a major part of most pool games. Object balls are arranged in a prescribed rack pattern, and the breaking player attempts to strike the rack with sufficient force to separate the balls and create legal scoring opportunities. Different rulesets establish requirements concerning how many balls must reach cushions, whether a ball must be pocketed, what happens if the cue ball is pocketed, and whether particular balls have to occupy specified positions in the rack.
In some games, pocketing a ball on the break allows the breaker to continue, while in others the break outcome determines how the table is subsequently played. Because break rules vary significantly, a player should know the governing rules before assuming that a particular break result automatically wins, loses or establishes a group.
After the break, the basic objective depends on the game. In eight ball, players usually play either solids or stripes and must legally clear their group before attempting the eight ball. In nine ball, the lowest numbered object ball remaining must be contacted first, but the player may legally pocket a higher numbered ball through a combination if the first contact requirement is satisfied.
In ten ball, the same lowest ball principle applies with additional requirements concerning called shots under common rules. Straight pool generally permits players to choose the object ball and pocket, subject to the applicable calling rules. These different objectives show why the phrase basic rules of pool must be treated as a family of rules rather than a single procedure.
A legal shot normally requires the cue ball to be struck with the cue tip and then to make the required first contact with an object ball. In rulesets that require a ball to be pocketed or a ball to contact a cushion after the first legal contact, failure to meet the requirement can result in a foul. The exact requirements vary.
Players also cannot generally touch or move balls illegally with their hands, clothing or equipment, and intentionally manipulating the table outside permitted shot procedures is prohibited. The cue ball must be controlled so that the stroke does not produce an unauthorised double hit, push stroke or other illegal contact. These rules exist to ensure that the result of each shot comes from a controlled cue action rather than physical manipulation of the balls.
Fouls are an important part of basic pool rules because they provide the main mechanism for penalising illegal play. Common fouls include pocketing the cue ball, contacting the wrong object ball first, failing to make the required cushion contact after legal contact when no ball is pocketed, touching a ball accidentally or deliberately, and playing an illegal stroke.
Under many modern American rulesets, a standard foul gives the incoming player ball in hand, allowing the cue ball to be placed in a permitted location before the next shot. Some games or local rules impose different penalties, and English pool rules can differ substantially from American rules. A player should therefore distinguish official tournament rules from informal house rules, which can produce different outcomes for identical shots.
Winning conditions also vary. In eight ball, the player who legally pockets all of their assigned group and then legally pockets the eight ball wins, subject to rules concerning fouls and illegal eight ball shots. In nine ball, the player who legally pockets the nine ball wins the rack, provided all required first contacts were legal. This means a nine ball can sometimes be legally pocketed early through a combination shot.
In straight pool, the winner is normally the player who reaches the predetermined point total first. Because winning conditions differ, a player must understand not just how to make a legal shot but what constitutes a winning shot and what circumstances cause immediate loss under the particular ruleset.
Safety play is also permitted in many pool disciplines and provides an important alternative to attacking. A player may deliberately leave the opponent without an easy scoring opportunity, provided the safety is legal under the applicable rules. In games with called shots, a defensive declaration may be required or specifically recognised by the rules. Strategic safety play can involve hiding the cue ball, blocking an object ball, sending balls towards cushions, or leaving an awkward angle.
The purpose is to reduce the opponent's chance of making a successful continuation while improving the player's future position. Pool is therefore not simply a race to pocket balls. At competitive level, players continually decide whether an attacking shot or a defensive shot produces the greater expected advantage.
The basic rules of pool are therefore best summarised as a framework rather than a single universal sequence: rack the balls correctly, make a legal break, follow the objective of the chosen discipline, make the required first contact, satisfy any cushion or pocketing requirements, continue shooting when entitled, accept the appropriate penalty after fouls, and win according to the discipline's specific victory condition. The most important practical rule is to identify which ruleset is being used before play begins.
World Pool Association rules, other national governing body rules, professional tournament regulations and informal house rules can differ on breaks, called shots, push outs, fouls, three foul situations and loss of game. A technically correct understanding of pool therefore requires both the general framework and the exact laws governing the chosen game.
