There are three prominent versions of roulette: American roulette, European roulette, and French roulette. All three are similar as far as the basics, with a few differences on the numbers on the wheel, the table layout and the betting.
In French roulette, there are special bets you can use that are known as call bets, or announced bets. Many casino players feel that having these additional bets available makes the game more interesting.
The “French bets” are based on which series of numbers are next to each other on the wheel, and you can bet on Voisins du zéro (the 17 numbers around the 0 on the wheel), Jeu zéro (a smaller set of numbers near 0), Le tiers du cylindre (the numbers in the third of the wheel across from the 0), and Orphelins (orphans, all the numbers not in one of the other sets). Of these bets, the Tier bets are by far the most popular.
Many people also feel that playing French roulette gives the players better odds than playing the American or European versions of the game. A couple of reasons for this are the La Partage and En Prison rules, which combine to give the players better odds. These rules are not usually used in American roulette.
La Partage means that when you bet on the even odds bets (like red or black, odd or even), if a 0 is spun on the wheel, you lose only half of your bet. In American roulette, you lose the full bet. En Prison is a variation of this. If you bet on an even money bet, and a 0 comes up on the wheel, you can choose to keep your bet for the next round. The croupier marks your bet to show that it “in prison”, and you can play that same bet again for another round.