Roulette is a casino game in which a small ball drops into one of 37 numbered compartments on a spinning wheel. Bets may be placed on a single number, various groupings of numbers, the color red or black, whether the number is odd or even, or if the numbers are high (19-36) or low (1-18). The payout for a winning bet depends on the total amount of chips wagered. Winning bets remain in play for the next spin unless otherwise stated.

The roulette wheel consists of a solid, slightly convex wooden disk with a metal rim. Around the edge are 36 numbered compartments (called canoes by roulette croupiers) painted alternately in red and black. The wheel also has two green compartments on American wheels which carry the signs 0 and 00.

After a ball is released from the spinning wheel, it bounces around the inner rim of the wheel and then falls into one of the compartments. A dealer then places a marker on the winning number and pays out the bets. The marker is then removed and the wheel is spun again.

Many fanciful theories exist as to the origin of the game, including that it was invented by 17th-century French physicist Blaise Pascal in his attempts to create a perpetual motion machine and that it was brought to Europe by Dominican monks from Ancient China. More likely, it is a descendant of the games hoca and portique, with its current layout and wheel structure being developed in France in the 18th century.

One of the most common roulette strategies involves combining bet types to give you the best odds of winning, although this requires a decent bankroll. Another popular strategy is called the James Bond system and involves varying your stakes depending on the results of previous bets.

A good way to minimize your losses is to avoid inside bets, which have a higher house edge than outside bets. Another strategy is to look at the patterns on the tracking board and try to recognize any trends.