There are two different types of roulette versions offered by casinos:
European Roulette which has 37 number slots on the roulette wheel.
American Roulette which has 38 number slots on the wheel.
American roulette game the wheel has 38 different slots where the ball may end up landing. Each number slot has an equal chance of becoming the winning number. A winning bet on one single number has a 35-1 payout. This means that the original bet is not lost and 35 times that amount is earned.
European live casino roulette game the wheel has 37 different slots where the ball may land and each number also has an equal chance of winning. The payout of a single number bet also has a 35-1 payout. The odds of the bet are what determine the payout. American roulette game the odds of landing on a single number bet are 37-1 and european wheel which is 36-1.
In American roulette there is a probability of 1/38 that the player wins 35 times the wager, and a 37/38 chance that the player loses their bet. The house advantage is: −1×37/38 + 35×1/38 = −0.0526 (5.26% house edge)
For European live roulette, a single number wins 1/37 and loses 36/37. The house advantage is: −1×36/37 + 35×1/37 = −0.0270 (2.70% house edge)
