European Roulette and American roulette are the two variants that you would point to, to highlight the subtle changes that slightly alter the way you can play. There are only two factors, the first is the number of numbers represented. The European game has a single zero and runs up to number 36, which is a total of 37 numbers. The American game matches this but also has an additional double zero option, therefore, players have a total of 38 numbers. The European wheel has no order of numbers, it is random. However, the American wheel does have a system where the sequence of numbers is found to be directly on the opposite side of the wheel.