Roulette is a casino game whose history dates back over 300 years. It was invented in a primitive form by the 17th-century French mathematician Blaise Pascal in his quest to create a perpetual motion machine, although many other fanciful stories about its origin also exist. By the mid-18th century, the roulette cylinder had been developed into its modern layout and wheel structure, and it became a popular game in casinos and gambling houses throughout Europe.
Roulette players place their chips on a betting mat where the precise location of each bet is indicated by a marker. Bets can be placed on a single number, various groupings of numbers, or color red or black. In addition, a player can bet on whether a particular number is odd or even, or if the numbers are high (19-36) or low (1-18).
The wheel consists of a solid wooden disk slightly convex in shape and around its rim are metal separators called frets that spin to reveal 37 compartments or pockets (called canoes by roulette croupiers) alternately painted in red and black. A single green compartment carries the number 0 on European-style wheels; American roulette wheels have an additional two green zero pockets. The dealer spins the wheel in one direction and then rolls a small ball in the opposite direction around a tilted circular track that runs along the outer edge of the wheel.
When the ball lands in one of the compartments, the dealer pays out winning bets. The payout amounts depend on the type of bet, and are listed on a large betting board adjacent to the table. The payouts are shown in terms of chips, but the actual number of chips is not disclosed until the bet has been won.
Roulette games are regulated by the Gaming Commission of the country in which they are played, and players must be 18 or older to play them. In the US, roulette is played at both land-based and online casinos, and there are also a number of live versions, where players bet in real time and have their bets placed by a human dealer.