Roulette is a casino game based on a wheel and ball. It is one of the oldest and most popular games in gambling establishments all over the world. It has its origins in France and was invented by French mathematician Blaise Pascal in the 17th century.

The game consists of a table with a circular betting mat, a wheel with 36 numbered divisions and a ball that spins around it. Before the ball is spun, bets are placed on specific numbers on the betting mat using chips. When the ball is hit, the chip on that number wins.

A player can place bets on a single number, groupings of numbers, whether the numbers are red or black, high (19-36) or low (1-18). The winning bet is paid out according to the odds.

There are many variations of the game, but the most common is European roulette. This version of roulette has a lower house edge and is a favorite of players both in physical casinos and online.

European roulette has a higher chance of winning than American roulette but the same house edge. The main difference between these two versions is that European wheels only have a single zero pocket, which automatically makes the house edge smaller.

Another interesting aspect of European roulette is the symmetries of the numbers on the wheel. All the low red numbers and low black numbers are on one side of the zero, while all the high red numbers and high black numbers are on the other. These symmetries make the odds of winning much more favorable, even though it is not as simple as it seems.

In addition, the symmetries also mean that you can win on certain bets with a high probability. These include the bets on 29-7-28-12-35-3-26-0-32, which pays out at 2-1 odds.

Some other bets in roulette include line bets, column bets, corner bets and even bets. In most cases, these bets pay out at even money, but sometimes they pay out at odds of 2-1.

The most commonly betted numbers in roulette are the numbers 1 to 36. These are usually divided into two groups: inside bets and outside bets.

The inside bets are the ones that have a specific location on the betting mat, while the outside bets are the ones that are located on any of the three sections of the table. These bets can be made by placing chips in the exact position indicated on the betting mat.