Roullete is a casino game in which players bet on a single number or various groupings of numbers, the colors red or black, whether the number is odd or even, or if the numbers are high (19-36) or low (1-18). Bets are made by placing chips on a betting mat. Once all bets have been placed, a ball is spun around the roulette wheel and if the bet hits the chosen number or grouping the player is paid according to the odds of that selection.

A typical roulette table has a large round betting area where the bets are placed by laying down chips, the precise location of which indicates the specific bet being made. Depending on which bet is being made, the odds for that bet are calculated based on probability. Bets that are placed on the numbers are referred to as inside bets while those that are not are called outside bets.

The roulette wheel is a solid wooden disk slightly convex in shape with a series of metal partitions, or frets, on its perimeter that divide it into thirty-six compartments painted alternately red and black. There is a single green compartment numbered zero on European-style wheels and, for the American version of the game, a second extra green division labelled 00.

The roulette ball is spun and, when it comes to rest, the dealer places a marker on the winning bet to indicate which number or grouping was hit. The dealer then pays the winners their winnings, takes the losing bets and re-positions the chips on the betting board to begin a new round of play.