In this game, the numbers on a wheel go up to 36. With American roulette, the wheel contains 38 numbers, from 00 to 36 while in both European and French roulette, the wheel only has 37 numbers – from 0 to 36.
The house edge is notably higher with American roulette because essentially, you have a 1 in 38 chance of the ball landing on your number instead of just a 1 in 37 chance as in European and French roulette. This is only true for number bets though, not black or reds.
The numbers are also laid out differently with the American variation, and what’s commonly referred to as side bets are called ‘pattern bets’ in European and French versions.