The object of roulette is to correctly guess which number a small marble will land on when the roulette wheel slows or stops. The roulette table consists of a wood and metal bowl-shaped wheel, about three feet in diameter, and a table layout for placing bets. The wheel is divided into thirty-eight pockets numbered 1 through 36, plus 0 and 00. The 0 and 00 pockets are green; of the remaining pockets, half are red and half are black. The dealer, or croupier, spins the wheel and releases a small white ball that travels in the opposite direction around the top of the wheel. As the ball loses velocity, it falls into the bowl of the wheel and skips over the buffers that separate each pocket, eventually coming to rest in one pocket. Most roulette tables in U.S. casinos allow up to six people to play at one time.