Roullete is a casino game in which players place bets on the number or grouping of numbers that they believe will come up when the dealer spins the wheel. Each bet is staked by placing chips on a betting mat, the precise placement of which indicates the bet being made. Bets can be placed on one or more numbers, groups of numbers (such as the second dozen), whether the number is odd or even, and the colour red or black.
The wheel consists of a solid disk, slightly convex in shape and with a series of metal separators around its edge known as frets or canoes. Thirty-six of these compartments, painted alternately in red and black, are numbered non-consecutively from 1 to 36. On European wheels there is also a green compartment numbered 0, and on American roulette wheels two additional green compartments labelled 0 and 00.
Each table carries a placard with a description of the minimum and maximum bets permitted. Players should choose a table within their budget and avoid jumping between different tables, as this can make the game more confusing and their odds of winning less certain. When they have won a round, players should leave their winnings on the table unless they have specifically requested that their money be removed.
Many systems have been proposed for beating roulette, some simple and some complex, but none has been proven to be consistently successful. Some gamblers claim to have gained an advantage by seeking out rigged wheels, but this has not been scientifically proven to be the case.