Roulette has a relatively high house edge, generally 5.26%. The casino game with the lowest house edge is craps. If you play only the pass line, the house edge is 1.414…%. There’s a better craps bet, don’t pass, which has a house edge of 1.36%.

Most casino games have a fixed edge and it is always in the house’s favor, unlike blackjack, in which the advantage swings back and forth between dealer and player. The house has the edge more often than the player and that is how they make money against most players. Betting more when the edge is in the player’s favor and less when not is essentially what counting cards is about. When the edge is in the player’s favor can be ascertained by counting cards. But counting cards is not easy, and the golden age of blackjack is long over, that is, casinos look for and bar card counters, who need elaborate preparations and also modify their play to escape notice, thereby lowering their already minuscule edge. Because the house always has the best of it, there are no professional roulette players, but you can very easily reduce the house edge. You have to look for the best games. Roulette gets its edge by not paying the true odds against an event happening.

Roulette wheels have one or more zeros that make this happen. An American (double 0) roulette wheel has 38 slots (36 numbers plus 0 and 00). So, if you bet, for example, on the number 11, it ought to pay 37 to 1 (because any number has a 1 in 38 chance of coming up), but it pays only 36 to 1. If you play that number 38 times for $1, it should come up once, but when it does, you get paid $36. In 38 tries (over the long run), you bet $38 and win $36, for a net loss of $2. The house edge, then, is 2/38 (as a decimal, 0.0526315…, or about 5.26%). If you make one of the even money bets (red/black, odd/even, 1-18/19-36), in 38 spins (again, over the long run), black comes up 18 times, red comes up 18 times, 0 once, and 00 once, so you bet $38 and win $36, that is, you have a net loss of $2 for the same house edge. Every bet on the American roulette wheel has the same house edge, except one. The First Five bet, on 0, 00, 1, 2, and 3, pays 6 to 1, and the house edge is 7.89%. You don’t ever want to make that bet.But you can do better than that. European (single 0) roulette wheels have only one zero. A European roulette wheel has 37 slots (36 numbers plus 0). So, if you bet, for example, on the number 11, it ought to pay 36 to 1 (because any number has a 1 in 37 chance of coming up). If you play that number 37 times for $1, it should come up once, but when it does, you get paid $36. In 37 tries (over the long run), you bet $1 37 times and win $36 once, for a net loss of $1. The house edge, then, is 1/37 (as a decimal, 0.027027…, a repeating decimal, or about 2.7%). If you make one of the even money bets (red/black, odd/even, 1-18/19-36), say you bet black, in 37 spins (again, over the long run), black comes up 18 times, red comes up 18 times, and 0 once, so you bet $37 and win $36, that is, you have a net loss of $1 for the same house edge.