The game is played with three balls of equal size and weight, one red, one white, and one spot-white. The diameter of a ball must be not less than 21⁄16 inches, nor more than 23⁄32 inches. The diameter of a match ball, under National Rules, is 25⁄64 inches.
The choice of balls and order of play is, unless mutually agreed upon, determined by "stringing" (i.e., playing from baulk up the table, so as to strike the top cushion). The striker whose ball stops nearest the lower cushion may take which ball he likes, and play, or direct his opponent to play, as he may deem expedient. In stringing, under National Rules, the players must both play at the same time.
The red ball is, at the opening of every game, placed on the billiard spot, and must be replaced after being pocketed or forced off the table. If the billiard spot be occupied, the red ball must be placed on the pyramid spot, or, if that also be occupied, on the centre spot.
When any player plays from baulk, he must place his ball within the half-circle, or on the line that contains it.
Whoever breaks the balls (i.e., leads off) must play out of baulk, though it is not necessary that he shall strike the red ball, and he may give a miss in or out of baulk. But, if in baulk, he must first strike a cushion out of baulk. No player who is in hand is allowed to strike any ball in baulk, or on the baulk-line, unless his ball has first struck a cushion out of baulk. Should, however, a ball be out of baulk, the player in hand may strike any part of that ball without his own ball necessarily going out of baulk.
The player continues to play until he ceases to score, when his opponent follows on.
The various strokes are as under: