The Basic Rules of Roulette
Roulette is one of the easiest casino games to learn and one of the most rewarding to understand in depth. A wheel spins, a ball lands, a result follows. Inside that simplicity lives a complete mathematical system: defined bets, exact payouts and odds, and a casino edge that never moves. This page covers every rule, every bet, every payout in full.
How Roulette Works
Every round follows the same five-step sequence, whether the wheel is physical or digital, live dealer or RNG-driven.
The Wheel and the Table
The wheel and the betting layout are two separate physical objects that represent the same set of numbers. A European wheel holds 37 pockets numbered 0–36. Zero is green. The other numbers alternate red and black. The numbers are not laid out in sequential order around the wheel — they follow a standardised pattern that distributes high and low, red and black, odd and even as evenly as possible. An American wheel adds a second green pocket (00), bringing the total to 38 and pushing the casino’s edge from 2.70% to 5.26%. The full mechanics live on the double zero wheel page.
| Component | European | American |
|---|---|---|
| Total pockets | 37 | 38 |
| Green pockets | 1 (zero) | 2 (0 and 00) |
| Red pockets | 18 | 18 |
| Black pockets | 18 | 18 |
| House edge | 2.70% | 5.26% |
Inside Bets — Numbers Only
Inside bets are placed directly on the number grid — on specific numbers or the lines between them. They cover fewer numbers, win less frequently, and pay considerably more when they do hit. Every inside bet on a European wheel carries the same 2.70% edge — what differs is risk profile and payout size. The complete side-by-side comparison of all 11 wager types is on the roulette bet options page.
Straight Up
A single-number bet. Chip goes in the centre of any numbered square, zero included. Pays 35:1. Win probability: 2.70% (1 in 37). The highest paying and lowest probability bet on the table.
Split Bet
A two-number bet on adjacent squares. Chip sits on the line between them — horizontally or vertically. Pays 17:1. Win probability: 5.41%.
Street Bet
Three consecutive numbers in one horizontal row. Chip goes on the outer edge of the row. Pays 11:1. Win probability: 8.11%. A European layout has 12 possible street bets.
Corner Bet (Square Bet)
Four numbers forming a square on the grid. Chip sits at the centre intersection where all four meet. Pays 8:1. Win probability: 10.81%.
Trio Bet
A three-number bet that includes zero. Only two combinations exist: 0-1-2 or 0-2-3. Chip goes at the intersection of zero and the two numbers. Pays 11:1. European and French wheels only — not available on American.
Six Line (Double Street)
Six numbers across two adjacent rows. Chip sits at the outer edge where the rows meet. Pays 5:1. Win probability: 16.22%. A staple in combination betting and a common building block for grid-based systems.
| Bet type | Numbers covered | Payout | Win probability | Chip placement |
|---|---|---|---|---|
| Straight Up | 1 | 35:1 | 2.70% | Centre of number |
| Split | 2 | 17:1 | 5.41% | Line between two numbers |
| Street | 3 | 11:1 | 8.11% | Outer edge of row |
| Trio | 3 (incl. 0) | 11:1 | 8.11% | Intersection of 0 and two numbers |
| Corner | 4 | 8:1 | 10.81% | Centre of four-number square |
| Six Line | 6 | 5:1 | 16.22% | Edge where two rows meet |
Outside Bets — Red, Black and Beyond
Outside bets sit in the boxes around the number grid. They cover large groups of numbers, win more often than inside bets, and pay proportionally less. Even-money wagers pay 1:1 — the smallest payout ratio on the table but with the highest hit rate. One critical detail: the single zero is not covered by any outside bet. When zero lands, every outside bet loses (unless La Partage or En Prison applies).
Even-Money Bets (1:1)
Three bet types pay 1:1 and each cover 18 numbers. Win probability: 48.65% on a European wheel.
- Red / Black — all 18 red numbers or all 18 black numbers.
- Odd / Even — all odd numbers or all even numbers. Zero counts as neither.
- Low / High — numbers 1–18 (Low) or 19–36 (High).
Dozen and Column Bets (2:1)
Both cover 12 numbers and pay 2:1. Win probability: 32.43%.
- Dozen — 1st Dozen (1–12), 2nd Dozen (13–24) or 3rd Dozen (25–36).
- Column — one of three vertical columns of 12 numbers on the layout. The numbers in each column are not sequential — check the table.
| Bet type | Numbers | Payout | Win probability |
|---|---|---|---|
| Red / Black | 18 | 1:1 | 48.65% |
| Odd / Even | 18 | 1:1 | 48.65% |
| Low (1–18) / High (19–36) | 18 | 1:1 | 48.65% |
| Dozen (1st / 2nd / 3rd) | 12 | 2:1 | 32.43% |
| Column | 12 | 2:1 | 32.43% |
Special Rules: La Partage and En Prison
Both rules apply only to even-money outside bets, and only when the ball lands on zero. They are standard on French Roulette tables and occasionally available on European tables. Both cut the edge on even-money bets from 2.70% to 1.35% — the lowest figure in standard roulette.
Announced and Call Bets
Announced bets cover specific sections of the physical wheel rather than positions on the betting grid. They exist on European and French tables only — never American. Players call them out by name to the croupier and they are placed as multi-chip combinations. Many online tables include a racetrack interface for direct placement.
| Bet name | Numbers covered | Chips required |
|---|---|---|
| Voisins du Zéro (Neighbours of Zero) | 0, 2, 3, 4, 7, 12, 15, 18, 19, 21, 22, 25, 26, 28, 29, 32, 35 | 9 |
| Tiers du Cylindre (Third of the Wheel) | 5, 8, 10, 11, 13, 16, 23, 24, 27, 30, 33, 36 | 6 |
| Orphelins (Orphans) | 1, 6, 9, 14, 17, 20, 31, 34 | 5 |
| Neighbours Bet | Any number plus 2 each side on the wheel — 5 numbers | 5 |
The House Edge Explained
The house edge is the casino’s mathematical advantage on every bet. In roulette it comes from one place: payouts are priced as if there are 36 numbers on the wheel, but the wheel actually holds 37 (European) or 38 (American). That extra pocket is where the edge lives.
On a straight-up bet, the fair payout would be 36:1. The casino pays 35:1. That one-unit gap, averaged across every possible outcome, becomes the 2.70% margin.
Practical math: every €100 wagered, the casino expects to keep €2.70. Over 1,000 spins at €10 per spin — €270 of expected losses. No betting system changes this. Systems redistribute when and how much you win and lose, never the underlying expectation. The full per-variant breakdown lives in the house edge analysis, and any individual scenario can be modelled with the payout calculator.
Which Variant Should You Play?
The variant choice is the single biggest decision you make at a roulette table. It outweighs every betting system and every strategy.
| Variant | Pockets | House edge | Best for |
|---|---|---|---|
| French Roulette + La Partage | 37 | 1.35% | Even-money players — best edge available |
| European Roulette | 37 | 2.70% | All players — global default |
| American Roulette | 38 | 5.26% | Avoid if European is offered |
| Mexican / Triple Zero | 39 | 7.69% | Novelty only — always avoid |
Simple decision tree: French with La Partage if available and you favour even-money bets. Otherwise European. American only when no single-zero alternative exists in the venue. Never Mexican or Triple Zero when a standard wheel sits at the same stakes.
Table Etiquette
At a physical casino, etiquette is expected. Online, most rules are enforced by the interface itself — but knowing them explains how the game is meant to flow.
Frequently Asked Questions
How many numbers are on a roulette wheel?
A European wheel has 37 numbers: 0 through 36. An American wheel has 38: 0, 00 and 1 through 36. A Mexican (Triple Zero) wheel has 39. Fewer zero pockets means a lower house edge — always pick the wheel with the fewest.
What is the best bet in roulette?
Every bet on a European wheel carries the same 2.70% edge — no bet is mathematically better than another. The choice is about variance, not value. Low variance and long sessions: even-money outside bets. Single-spin payout maximisation: straight-up numbers. Balance between the two: six lines or corners. No bet beats the underlying edge.
What happens when zero lands?
Every outside bet loses — red/black, odd/even, high/low, dozens, columns. Inside bets placed directly on zero pay 35:1 like any other number. If La Partage is in effect, even-money outside bets get half the stake back. If En Prison is active, even-money bets are locked for one more spin.
Can you bet on every number at once?
Yes, but it does not help. A €1 straight-up bet on all 37 European numbers costs €37 in total. Exactly one wins and pays €35 — leaving a €2 loss every spin. The edge is built in regardless of coverage. The only way to lower it is choosing a better variant or finding a La Partage table.
What is the Gambler’s Fallacy?
The false belief that past results affect future spins. After ten consecutive reds many players think black is “due.” It is not. Each spin is independent — the wheel carries no memory. The probability of red or black on the next spin is always 48.65%, no matter what the previous 100 spins did.
Do roulette strategies work?
Betting systems like Martingale, Fibonacci and D’Alembert manage variance and session structure — they do not change the house edge. A well-applied system extends play time on a fixed budget and produces more consistent sessions. None of them yields a long-term mathematical advantage. The full comparison sits in the strategy index.