Roullete or simply Roulette is a casino game in which a ball is dropped into a revolving wheel that has numbered slots. The player makes a bet on which number, section or color the ball will land in and if they win the bet they are paid according to their betting odds. There are a variety of bets one can place, including single numbers, various groupings of numbers, red or black and whether the number is odd or even.

The game of Roulette as it is known today originated in 17th century France and probably combined elements of the earlier games hoca and portique, along with Biribi, an Italian game that involved predicting which numbered ticket would be drawn from a bag. Roulette was not widely played until the late 18th century when it was introduced in gambling dens across the United States and France.

A Roulette wheel consists of a solid wooden disk slightly convex in shape with a metal perimeter. Around the rim are thirty-six compartments, called canoes by croupiers, painted alternately red and black and numbered nonconsecutively from 1 to 36. On European wheels a separate green compartment carries the sign 0. A second additional green compartment on American roulette wheels carries the sign 00.

Before the roulette wheel is spun, players make their bets by placing chips on a roulette table. The precise placement of the chips indicates the bet being made. The symmetries of the wheel and table are such that, for example, all the low red numbers and all the high black numbers are together on one side of the zero, while on the other is the 29-7-28-12-35-3-26-0-32 sequence (known as the second dozen). Based on these symmetries it is possible to construct bets with good odds of winning.