Roulette has offered glamour, mystery, and excitement to casino-goers since the 17th century. Its simple rules and relatively low house edge make it an attractive game for beginners, but it also offers a surprising level of depth for serious bettors.
The name “roulette” derives from the French diminutive for little wheel. In the game, players place bets on various fields which include one or more numbers, groups of numbers, the colors red and black, whether a number is odd or even, and so forth. Many casinos offer several forms of the game, including the popular mini roulette which uses a smaller wheel and has only 12 figures instead of the standard 36.
A croupier spins a small ball in a metal cup on a revolving disk called a roulette wheel. Its rim is divided into thirty-six compartments painted alternately red and black, with two green ones (or, on American wheels, 0 and 00). There are also a few other markings on the roulette wheel that distinguish it from others.
The rim of the roulette wheel is dotted with metal pins that divide the wheel into segments. A spherical ball, which may be made from ivory or from synthetic materials such as resin or Teflon, is dropped into the center of the wheel. When the wheel stops spinning, the ball lands in one of the compartments marked with the corresponding numbers or symmetries. The symmetries of the European wheel are 29-7-28-12-35-3-26-0-32, while that of the American wheel contains a sequence of 30-8-36-18-22-29. The symmetries are created by the fact that the first twelve of the thirty-six numbers on each side contain high black and low red numbers, while the second dozen has only low red and high black numbers. Regardless of which version of the game is played, a mathematical advantage can be gained by seeking out rigged wheels and betting against them.