More-stable and slower-burning collodion mixtures were eventually prepared using less concentrated acids at lower temperatures for smokeless powder in firearms. It is played using a cue stick, one white ball (the cue ball), fifteen red balls and six colours: a yellow (worth two points), green (three points), brown (four points), blue (five points), pink (six points) and black ball (seven points). Further up the table is the pink ball, which sits midway between the blue spot and the top cushion, followed by the red balls (one each), what is billiards placed in a tightly-packed triangle behind the pink. Finally, the black ball is placed on a spot 12.75 inches from the top cushion on a full-size table. If there is no room this side of the spot, it will be placed as close to the spot as possible in a straight line towards the bottom cushion, without touching another ball. Some players (most often amateurs) place the balls in numeric order but for the 9 ball; from the top of the triangle down and from left to right, i.e., the 1 on the foot spot, followed by the 2 then 3 in the second row, and so on.

If there is no available spot, it is placed as close to its own spot as possible in a direct line between that spot and the top (black end) cushion, without touching another ball. In both one-pocket and bank pool all fifteen object balls are racked entirely at random, with the center of the apex ball placed directly over the foot spot. The first ball must be placed at the apex position (front of the rack and so the center of that ball is directly over the table's foot spot). The most common shape of a rack is that of an equilateral triangle. A rack (sometimes called a triangle) is a piece of equipment that is used to place billiard balls in their starting positions at the beginning of a pocket billiards game. The 8 ball must be in the center of the rack (the second ball in the three-balls-wide row). At that time, the fourteen pocketed balls are racked with no apex ball, and the rack is so placed so that if the apex ball were in the rack, its center would rest directly over the table's foot spot.

In the initial rack in straight pool, fifteen balls are racked in a triangular rack, with the center of the apex ball placed over the foot spot. When you hear people talk of sidespin in pool, they’re talking about English (sometimes spelled english) under a different name. While offensive shots are crucial for winning games in 8 pool, it’s equally important to have a solid understanding of defensive or safety shots. Unlike traditional racks, template racks are left on the table during the break shot and removed at the players' earliest convenience. Play then continues with the cue ball shot from where it rested and the fifteenth ball from where it rested prior to racking. There are a total of 500 points available to a player, representing the combined value of a perfect score on all 76 shots, although not all games are played with the full shot catalogue. Traditional racks are in the form of triangular frames, usually made from wood, plastic or metal. For this reason, template racks are almost never used for games where it is common to slow-break (i.e. not create a large spread of balls) since it is significantly more likely that the rack will interfere with slow-rolling balls.

Diamond-shaped frames are sometimes used for the game of nine-ball (although a triangular rack can also be used) and template racks come in a variety of shapes. A number of rules have developed which detail what must be done when one or both of the cue ball and fifteenth object ball are either in the rack area at the time an intragame rack is necessary, or are in such close proximity to the intragame racking area, that the physical rack cannot be used without moving the one or the other. Rack may also be used as a verb to describe the act of setting billiard balls in their starting positions (e.g. "to rack the balls"), or as a noun to describe a set of balls that are in their starting positions (e.g. "a rack of balls", more often called a pack or a pyramid in British English). Because the game is played to a number of points normally far in excess of the fifteen points total available in the initial rack (in tournament play, one-hundred fifty points), multiple intragame racks are necessary. Wood tables, particularly those made of MDF, are more susceptible to warping from environmental conditions like humidity and temperature changes.