Roullete (French for “little wheel”) is a casino game where a ball is spun around a numbered and colored wheel to make bets on the outcome of the spin. The payout odds of different types of bets are based on probability. Players can choose to place bets on a single number, various groupings of numbers, whether they are odd or even, and the color red or black. The bets that are placed on the numbers are called inside bets and those that are placed on other sections of the wheel or betting layout are called outside bets.

A roulette wheel consists of a solid wooden disk slightly convex in shape and with thirty-six compartments, painted alternately black and red and numbered nonconsecutively from 1 to 36, plus two green compartments on American wheels that carry the signs 0 and 00. A croupier – who is sometimes known as a dealer – operates the wheel. The croupier also places chips on the table to indicate the bets to be made. The house gets its edge from the fact that if the winning number is a zero or 00, all outside bets lose. Bets are also placed on whether the winning number will be in the first dozen (1-18), the second dozen (12-18) or the third dozen (19-36). These bets are called “even money” and pay out at 2-1.