In the game, players may choose to place bets on either a number, a range of numbers, the color red or black, or whether the number is odd or even. To determine the winning number and color, a croupier spins a wheel in one direction, then spins a ball in the opposite direction around a tilted circular track running around the circumference of the wheel. The ball eventually loses momentum and falls on to the wheel and into one of 37 (in European roulette) or 38 (in American roulette) colored and numbered pockets on the wheel.

 

The pockets of the roulette wheel are numbered from 1 to 36, alternating between red and black. There is a green pocket numbered 0. In American roulette, there is a second green pocket marked 00. Pocket number order on the roulette wheel adhere to the following clockwise sequence:

Single-zero wheel : 0-32-15-19-4-21-2-25
17-34-6-27-13-36-11-30-8-23-10-5-24-16-33
1-20-14-31-9-22-18-29-7-28-12-35-3-26

Double-zero wheel : 0-28-9-26-30-11-7-20
32-17-5-22-34-15-3-24-36-13-1-00-27-10-25
29-12-8-19-31-18-6-21-33-16-4-23-35-14-2