Roulette (which means ‘little wheel’ in French) is a casino game that involves spinning a numbered wheel. A small ball is thrown onto the wheel while it is in motion and, if the ball stops in a number – or a grouping of numbers, or whether they are red or black or even or odd – the player wins. The game is easy to learn, and a number of different systems have been devised for playing it (and winning at it).

There are a few things to know before you play. Firstly, it is important to set your budget before you begin. Once you have determined how much money you are willing to risk, choose a table within that budget. Each table will carry a placard that describes the minimum and maximum bets allowed. Ideally, you should begin by wagering on ‘outside bets’, as these are cheaper and offer a greater chance of hitting than the inner numbers.

Once you have placed your bets, the croupier will spin the wheel. Then, he will drop the ball into one of the pockets marked on the roulette wheel. The players then wait as the ball bounces around the wheel and settles into a pocket marked with a particular number. If you made a bet on that number, you win.

The physics of roulette are complex, but the basics of the game are simple. The cylinder is made from a solid wood disc slightly convex in shape and, around its rim, are metal partitions called frets or separators (and sometimes canoes by croupiers). Thirty-six of these compartments are painted alternately red and black and numbered nonconsecutively from 1 to 36; on European wheels, there is also a green compartment labelled 0, and on American wheels two green ones labelled 0 and 00.

The symmetries of the wheel make the odds of winning 2-1 in any bet on a single number, or a range of numbers (the first dozen or second dozen). There are other, more complex, symmetries, such as the fact that all the high red numbers and the low black ones appear together on one side of the zero, or that the number 29-7-28-12-35-32-6-0 contains no numbers between 13 and 24 (which is known as the third tier). The material used to make the ball has an effect on its behaviour; a smaller, light ceramic ball makes more revolutions and jumps more unpredictably than a big ivorine one.