Roulette is named after a French word, literally meaning "small wheel". Players can choose to place an assortment of bets on the table - a number, a block or range of numbers, the colour red or black, or an odd or even number. To determine the winning number and colour, the croupier spins a wheel in one direction then throws a ball in the opposite direction, along a circular groove running around the top of the wheel. When the ball eventually slows down, it falls into one of 37 equally-sized coloured and numbered pockets set into the wheel, from which the winning bets are revealed.

The returns can be significant if a stake is placed on the single winning number, but a player can double his or her stake simply by selecting one of the 50/50 options (e.g. red or black, odd or even).