Wheel · Numbers · Chance
Roulette
Roulette settles every bet from the pocket in which a ball comes to rest. A European wheel has 37 pockets numbered 0–36; an American wheel adds 00 for 38 pockets. The zero—and double zero—creates the house edge because payouts remain based on odds slightly more favourable than the true probabilities.
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The game at a glance
The game at a glance
Complete sequence of play
Complete sequence of play
- 01
Place chips
Before no more bets, chips are placed on a number or betting area. A chip across several lines corresponds to a precise combination of adjacent layout numbers.
- 02
Spin
The wheel turns and the ball travels in the opposite direction. Once no more bets is called, stakes should not be moved or added.
- 03
Result
The pocket where the ball settles determines every winning wager. The dealer marks it, clears losing chips and pays winners.
- 04
Next round
The marker is removed and another spin begins. Previous results may be displayed but do not alter the probability of the next spin.
Reference table
Standard payouts
| Bet | Numbers covered | Net payout |
|---|---|---|
| Straight up | 1 | 35 to 1 |
| Split | 2 | 17 to 1 |
| Street | 3 | 11 to 1 |
| Corner | 4 | 8 to 1 |
| Dozen / column | 12 | 2 to 1 |
| Even-money bet | 18 | 1 to 1 |
Understand before staking
Understand before staking
Inside bets
Straight-up, split, street, corner and six-line bets cover one, two, three, four or six layout numbers. The quoted payout is normally net winnings with the original stake returned. A straight-up bet pays 35 to 1 even though its chance is one in 37 or 38; that gap creates the edge.
Outside bets
Red/black, odd/even and low/high cover 18 numbers but normally lose to zero. Dozens and columns cover twelve. These bets win more often and pay less than a single number without removing the edge. No arrangement of simultaneous bets produces a guaranteed profit over all pockets.
La partage and en prison
Some French or European tables apply la partage, returning half an even-money stake when zero appears. En prison may keep it for the next spin. These rules reduce the edge on specified even-money bets, but they must be explicitly posted and do not apply across the layout.
Streaks and martingales
Ten reds in a row do not make black due. With a fair wheel every spin retains the same probabilities. Doubling after losses creates frequent small recoveries but rapidly produces very large stakes, table-limit problems and severe cumulative loss. It changes the shape of risk, not the mathematical edge.
Official sources to consult
These references cover the jurisdiction stated in their titles. Applicable rules, variants and payouts remain those of the specific game and jurisdiction.
Worked example · Explicit assumptions
Why two wheels are not equivalent
A single-number bet paying 35:1 on 37 equally likely pockets has expectation (35 − 36) / 37 = −1/37, about −2.70% per euro. With 38 pockets and the same payout, it is (35 − 37) / 38 = −2/38, about −5.26%.
Assumptions: balanced wheel, identical payout and no special rule. A martingale changes neither pockets nor payouts and introduces large-stake risk.
Understand and check the calculationsCheck understanding · Explicit assumptions
Does a streak change the next number?
Assume a balanced 37-pocket wheel and independent spins. Red occurred five times. What is the next chance of number 7?
Show the calculation and its limits
It remains 1/37, about 2.7027%. Previous outcomes do not change that probability under these assumptions. A number probability does not describe bet profitability.
FAQ
Frequently asked questions
What is the basic principle of Roulette?
Roulette settles every bet from the pocket in which a ball comes to rest. A European wheel has 37 pockets numbered 0–36; an American wheel adds 00 for 38 pockets. The zero—and double zero—creates the house edge because payouts remain based on odds slightly more favourable than the true probabilities.
Which rules should I check before playing Roulette?
Before no more bets, chips are placed on a number or betting area. A chip across several lines corresponds to a precise combination of adjacent layout numbers. Also check the exact variant, payment table, stake and session cost before playing.
Does understanding Roulette make it profitable?
No. Understanding the rules helps prevent mistakes but does not remove chance, costs or the house edge.