Roulette is a gambling game in which players place bets on the outcome of a spin of a numbered wheel. The wheel has 37 or 38 compartments marked red and black, with a single green division labeled zero (on American tables there is an extra green compartment labelled 00 which makes the game a worse proposition financially than its European counterpart). The players place bets on what number the ball will land in by laying down chips on a betting mat, the precise placement of the chip marking the bet being made. The bets on six or fewer numbers are called Inside bets while those on 12 or more are known as Outside bets.

The game was probably invented by a French mathematician at the end of the 17th century, Blaise Pascal, who was then working on a perpetual motion machine. His experiments with probability resulted in the wheel and its modern layout. The wheel was later brought into the United States, where it became popular in casinos and gambling dens due to its simplicity of operation and absence of devices designed to enable cheating.

Before each spin of the wheel, the dealer will announce “No more bets, please.” Then the ball is released into the spinning wheel. As it spins, it will bounce around the various compartments until it lands in one of them. If the player has bet on that number, or the color of the number (red or black), or an even-money bet such as Odd or Even, they win.

While it is possible to make a profit from the game, it is unlikely for any individual to consistently gain an edge over the house, and professional gamblers are usually barred from playing in land-based casinos. This is because a reputable casino will not allow anyone to play at a table with a system that violates their terms of business.

A popular strategy for winning at roulette involves using a Fibonacci mathematical sequence. This enables players to picture how much they need to win, and then to increase their bet amounts accordingly, ensuring that they do not exceed their bankroll. It is also possible to bet on a single number, which pays out at a rate of 36 chips for every dollar wagered. The payout for this bet varies depending on the location of the number, with zero costing 17 chips and number 1 paying out 392 chips.