Roulette is a casino game in which a ball spins around a wheel with numbered pockets and players make bets on what number or type of bet will appear. The game has a long and colorful history in casinos and gambling houses worldwide. Its simple rules and relatively low house edge make it a popular game with both casual gamblers and serious betters. It can be found in many online casinos as well.

Roulette games vary from one casino to the next, but most feature a small wheel with numbered pockets into which a small ball is released. The game of roulette evolved in the 18th century, and its popularity spread from France to the rest of Europe. It is now a staple of most land-based and virtual casinos.

The game of roulette is based on probability, the study of how likely it is that a particular event will occur. Specifically, the game is based on the fact that there are thirty-six compartments in the roulette wheel, which are alternately painted red and black and numbered nonconsecutively from 1 to 36. On European-style wheels, there is a 37th compartment that is painted green and carries the sign of 0. On American-style wheels, there are two green compartments on opposite sides of the zero.

Players place bets on the outcome of a single revolution of the roulette wheel by placing chips on a betting mat, with the precise location of the chip indicating the bet being placed. Bets on six numbers or less are known as “Inside bets”, while those on 12 or more are called “Outside bets”.

There are a variety of theories on the origin of roulette, including that it was invented by French mathematician Blaise Pascal in the 17th century. Regardless of its exact beginnings, the modern roulette wheel and table were developed in the late 18th century, and it quickly became popular in the casinos and gambling houses of Europe.

Roulette tables are usually marked with a placard describing the minimum and maximum bets allowed. Players should choose a table that allows them to play within their budget, and should always be aware of the house edge. Also, it is important to understand that the material of the roulette ball has a significant impact on its performance. For example, a small ceramic ball may make more revolutions on the wheel and jump around more unpredictably before landing on a number than a large ivorine ball.