Roullete is a casino game in which players bet on the outcome of a spinning wheel. There are many different types of bets, including single-number bets, groupings of numbers and color bets (red or black). There is also an option to bet on whether a number is odd or even, high or low. The game of roulette is popular both in land-based and online casinos, with variations including multiball games with up to three balls, no-zero wheels and mini-roulette versions with a smaller wheel and the ability to bet on just 12 numbers.
The modern roulette wheel is a solid, convex disk with grooved segments or compartments around the circumference, into which a small ball is spun. The compartments are painted alternately red and black and numbered 1 to 36 in a seemingly random pattern, with a special green division marked 0 on European wheels. On American tables there is a second green division marked 00, which significantly increases the house edge over the European game.
During the course of a game, players place bets by laying chips on a special betting mat, the precise location of the chip showing which particular bet is being made. Prior to the spin of the wheel, the dealer clears the table of losing bets and places a marker on the winning number. The chips are then re-staked on the same bet.
Successful roulette strategies often involve prediction of which compartment the ball will come to rest in as it slows down and finally drops into one of the numbered slots. This can be achieved by looking for an imbalance in the machine, whether through sloppy maintenance or, as in some cases, intentional tampering to give gamblers an advantage.
The game is played with a ball that is released in the opposite direction of the revolving wheel. Bets are placed against the house on the numbers that will appear, and may be placed individually or as groups or a combination of both. The odds of a bet are based on the probability that each segment will contain the winning number.
In addition to a simple bet on a single number, other bets include odd or even numbers, black or red, and the groups of numbers (the dozen and the straight). Some of these bets have additional pay-offs such as the en prison rule, which pays out 35:1 if the losing bet is a color or number. While some gamblers have developed complex systems for predicting where the ball will fall, most simply play by chance and rely on their luck to win. A large portion of the money won by roulette is collected by professional gamblers. There are no guarantees of winning, and if you do win, it is important to cash out your chips as quickly as possible and to avoid dipping into them for future bets.