Roullete (French for ‘wheel’) is a casino game in which a small ball is thrown onto a numbered wheel and spun until it settles on one of the numbers. The player can then bet on that number or various groupings of numbers, the color red or black, or whether it is odd or even or one of two value ranges. The odds of hitting a particular number remain unchanged from spin to spin, regardless of what happened previously.

Roulette is played on a table marked off with numbers from 1 to 36 and sometimes one or two zeros. It is surrounded by several other sections affording players a variety of betting opportunities, and has in the center a revolving dishlike device called a roulettewheel into which a small ball is dropped to come to rest in one of the 37 or 38 compartments on the wheel.

The earliest known version of the game was devised in the 17th century by Blaise Pascal, the French mathematician and philosopher, as part of his efforts to develop a perpetual motion machine. The modern roulette wheel, with its alternating red and black numbers and a single green compartment for the zero, was introduced a century later in France.

When a player decides to place a bet, they give their money to the dealer (or croupier) who gives them coloured chips of that denomination. The chips have a different colour for each player to make it easier for them to identify their own bets. The dealer will also ask each player what amount they would like to designate for each chip.

During the time that bets are being placed, the croupier spins the roulettewheel and then drops the small ball into one of the pockets on the wheel. All bets are still active at this point, so players can continue placing bets on their favourite number or groups of numbers until the croupier announces that no more bets can be made.