Definition of legal

As in many other sports, "legal" means not causing or likely to cause a foul (the opposite being illegal). A legal hit is one in which the requirements for a non-foul hit are met (e.g., in nine-ball, the lowest-numbered ball on the table was hit by the cue ball first, and at least one object ball was pocketed, or any ball reached a cushion, after the hit on the first object ball.). A legal shot is one in which no foul of any kind was involved (e.g. there was not a double hit by the cue, the player's bridge hand did not move a ball, etc.). A legal stroke is one in which the cue stroke obeyed the rules (e.g. the shooter did not perform an illegal jump shot by scooping under the cue ball with the cue tip). A legal ball is a ball-on, an object ball at which it is permissible for the player to shoot. And so on. The term can be used in many ways consistent with these examples ("legal pocket" in one-pocket, "legal equipment" under tournament specifications, etc.).

24 Random Essential Billiards Terms

Either of the two longer rails of a billiards or pocket billiards table, bisected by a center pocket and bounded at both ends by a corner pocket. Also called a long rail.
Describes the propensity of a player losing small sums of money at gambling to suddenly sharply increase the stakes; often continuing to lose until broke. Compare Chasing one's money.
The Higher Education Snooker and Pool Council is a voluntary, not-for-profit organisation established to promote cue sports in institutions of higher education on the island of Ireland.
To apply chalk to the tip of your cue before a shot.
This is English that turns into reverse English after contact with the object ball. This will close up the angle on a bank.
The use of the correct amount of cue ball speed in position play to achieve proper shape for a subsequent shot.
This is the final object ball you need to pocket in order to win a game of one pocket.

1- A tip tool with fine, sharp points used to roughen the cue tip to better hold chalk after it has become hardened and smooth from repeated impacts with the cue ball. Tappers are firmly tapped on or pressed against the tip. Scuffers serve the same purpose, but are used differently.

2- Describes a shot where one has a chance to miscue. Usually heard in reference to long draw shots. As in, "It's a tip-tapper!".

This is the portion of the joint that actually connects the two sides of the cue, often called the pin or male end. This comes in a number of different sizes and shapes which some believe has an influence on the hit of the cue stick.
In snooker, a phrase used to describe a situation where the player has an easy pot and in general the balls are in a position to go on to make a sizeable break.
The lamentable practice of not following through with the cue straight, but veering off in the direction of the shot's travel or the side english is applied, away from the proper aiming line; a common source of missed shots.
The World Pool-Billiard Association (WPA) is the international governing body for pocket billiards (and also sactions rules and events for carom billiards games as well, in cooperation with other bodies). The group was formed in 1987, and was initially headed by a provisional board of directors consisting of representatives from the United States, Japan, Sweden, and Germany.
A pool room employee who plays with a good degree of skill.
A point bead on a scoring string.
The Union Mondiale de Billard (French for World Union of Billiards) is the world governing body for carom (carambole) billiard games. The organization was founded in Madrid, Spain on 1 June 1959, and is dedicated to promoting the modern carom billiards games. The UMB monitors and controls international carom competitions and tournaments, and organizes an annual World Three-cushion Billiards Championship.
National Amateur Pool League.
This is the red colored object ball in carom games.
In snooker, any of the 15 balls worth 1 point each that can be potted in any order. During the course of a break a player must first pot a red followed by a colour, and then a red and colour, etc., until the reds run out and then the re-spotted six colours must be cleared in their order. Potting more than one red in a single shot is not a foul - the player simply gets a point for each red potted.
In blackball, one of two groups of seven object balls that must be potted before the black. Reds are spotted before yellows, if balls from both group must be spotted at the same time. Compare stripes; contrast yellow ball.
In carom billiards, the object ball that is neither player's cue ball.
This is when you aim at one particular object ball that is not meant to go in the pocket, but is instead meant to contact another object ball which will continue the combination process or be pocketed.
Random method for pairing of opponents when setting up a bracket system for a tournament.
Alternate name for the cue ball.
In carom billiards games, a term for the opponent's cue ball, which for the shooting player is another object ball along with the red.
This is the ball that sits in the front, or apex, position in the rack.
A bank shot is when the shooter (player) bounces the cue ball or the object ball (after it is hit by the cue ball) off a rail in an attempt to make the shot. A successful bank shot will result in sinking the object ball or a defense that will make it very difficult for the opponent to attempt their shot.
A ball positioned near a pocket so that a particularly positioned object ball shot at that pocket will likely go in off it, even if aimed so imperfectly that if the warrior was absent, the shot would likely result in a miss. Usually arises when a ball is being banked to a pocket.
Used in snooker in reference to the position of the cue ball. It is "below" the object ball if it is off-straight on the top cushion side of the imaginary line for a straight pot (e.g. he will want to finish below the black in order to go into the reds).