Roulette is simple: a ball is spun around a numbered wheel, and you bet on where it will land. The variety comes from the number of different bets you can place, from a single number to half the table.
A European roulette wheel has 37 pockets: the numbers 1 to 36, coloured red and black, plus a single green zero. An American wheel adds a second green pocket, the double zero, making 38. That extra pocket matters — see the odds section below.
Outside bets lose when the ball lands on zero. Some European tables return half of even-money bets on zero (called "la partage"); check the rules on your table.
Payouts are set as if zero did not exist. A straight-up bet pays 35:1, but on a European wheel the true odds are 36:1. That gap gives European roulette a house edge of about 2.70% on almost every bet. On an American wheel with the extra double zero, the house edge rises to about 5.26%. If you have the choice, a single-zero wheel is the cheaper game.
Systems such as Martingale (doubling your bet after every loss) change how your wins and losses are spread, but not the house edge. A long losing streak can reach the table maximum or your budget quickly, so these systems add risk rather than removing it.
Even-money bets such as red/black or odd/even win most often (18 of 37 numbers on a European wheel), but they carry the same house edge as other bets.
American roulette has an extra double-zero pocket, which raises the house edge from about 2.70% to about 5.26%.
No. Each spin is independent, and previous numbers do not affect the next result.
Zero is neither red nor black, odd nor even. When it comes up, outside bets lose (or lose half on la partage tables), which is where the house edge comes from.
18+ only. Gamble responsibly.