Roulette bets are inside (on numbers) or outside (on groups), and each pays in proportion to the numbers covered. On a European wheel a bet covering n of the 37 pockets pays 36/n minus 1 to 1, which is why every standard bet has the same house edge.
The roulette layout can look busy, but it is built from a few simple types of bet. Each is a group of pockets with a fixed payout.
Reading the layout
The numbers 1 to 36 sit in a grid of three columns and twelve rows, colored red and black. The zero is green and sits at the top of the grid. Boxes around the grid cover groups: the dozens, the columns, red or black, odd or even and low or high.
Inside and outside bets
Inside bets go on the numbers themselves or on the lines between them. Outside bets go on the groups around the grid. The table below is for a European wheel and gives the chance of winning each bet in one spin.
| Bet | Numbers covered | Pays | Chance to win on a spin |
|---|---|---|---|
| Straight up | 1 | 35 to 1 | 2.70% |
| Split | 2 | 17 to 1 | 5.41% |
| Street | 3 | 11 to 1 | 8.11% |
| Corner | 4 | 8 to 1 | 10.81% |
| Six line | 6 | 5 to 1 | 16.22% |
| Dozen or column | 12 | 2 to 1 | 32.43% |
| Red or black, odd or even, low or high | 18 | 1 to 1 | 48.65% |
Why the house edge is the same
A bet covering n pockets wins with probability n/37 and pays (36/n − 1) to 1. The average result for a stake of 1 is (n/37) × (36/n − 1) − ((37 − n)/37) = (36 − n − 37 + n)/37 = −1/37, about −2.70%, whatever n is. Choosing a bet changes how often you win and how big the wins are, not the average cost.
A hypothetical example: 100 spins at a stake of 10 each are 1,000 wagered. At 2.70% the average cost is 27, whether the stakes go on single numbers or on red.
What changes with the choice of bet
- Outside bets win often and pay little, so a bankroll moves in small steps.
- Straight-up bets win rarely and pay a lot, so a bankroll moves in large steps.
The two wheels differ in cost, not in layout; see European vs American roulette: house edge. Betting patterns that raise or lower the stake do not change these numbers; see betting systems and the Martingale myth.
See also: Gambling glossary; The gambler's fallacy, explained.
Frequently asked questions
Is any roulette bet cheaper than the others?
On a standard European wheel every standard bet has the same house edge, about 2.70%. The bets differ in how often they win, not in average cost.
What are call bets and neighbours?
They are shorthand for placing several inside bets at once. Each part still pays by the table above, so the edge is unchanged.
