Roulette House Edge

The casino odds in a roulette game are set by 35 to 1. This means that when you win the house pays you $35 and you get to keep your original $1 bet. The house edge is the amount the player loses on average to any bet made. If you bet on a single number in the European roulette game there is a probability of 1/37 that you win 35 times the bet, and a 36/37 chance that you will loose the bet. In European roulette the house edge is 2.70%. The green squares on the roulette wheel and on the table are the only house edge. When you place an outside bet you will always lose when 0 or 00 shows. The house also has an edge on inside bets where you have a 36 to 1 chance at winning a straight bet on a single number and the pay out is always set at 35 to 1.

Demonstration

To demonstrate the house edge in roulette, imagine placing straight $1 beter on all numbers 1-36 on a roulette table including single and double zero to assure a win. You would only get back 35 times your original bet of $1 having spent $38. Many people think that the green numbers are "house numbers" and that by betting on them the house edge increases. However, while the house's advantage comes from the existence of the green numbers they are no more or less likely to come up than any other number.

Dutch players can find a roulette strategie translation here.