ONLINE ROULETTE TYPES
There are three types of Roulette wheels:
The American Wheel
This wheel has 38 partitions that are numbered from 1 to 36 plus 0 and 00 (see roulette layout link for the image of the wheel). Even numbers are red and odd numbers black. "0" and "00" are green. With extra "00" partition the house has an good advantage of 5.26% (Whenever 0 or 00 are hit, all bets lose.). This means that for every $100 bet the casino make $5.26. There is also "Five Number Bet" which gives the casino a 7.89% edge over the player. The betting numbers are 0, 00, 1, 2, 3 at the same time. It is the worst bet in roulette, never make "five number bet". American roulette are more popular in North American casinos, however, you can find there European roulette too.
The European Wheel
This wheel has 37 partitions that are numbered from the 1 to 36 and 0. With having only 1 zero the house has an advantage of 2.70%. This means that for every $100 bet the house is making $2.70 profit. In the European roulette the house advantage is twice less then in American wheel game. That's why the European wheel is much more popular and you can win much easily playing single zero game.
To make your life even better, the casinos and especially online casinos have a rule called "en prison" (or also called "La Partage" rule) which is similar to the Atlantic City casino rule. If you make an even-money outside bet and the ball lands on 0 you either lose half the bet or your bet is "imprisoned" and you have to let it ride on the next spin. The casino edge on this bet is cut in half to 1.35% which makes it one of the best bets in the casino and almost four times better than the same bet when it's made on a standard American double-zero roulette wheel.
However, the average house edge for a roulette with en prison rule does not decrease too much - the edge is 2.63%. The roulette with "en prison" rule also called "French roulette". You can find this French roulette game version at Microgaming online casinos.