Roulette Rules Explained
Roulette looks simple from the outside — a wheel, a ball, a number — but every spin sits on top of a complete mathematical system. Fixed payouts. A constant house edge. Bet types with identical expected value but very different volatility. This page covers the rules in full: how a round flows, which bets exist, what each pays, and why the wheel you choose matters more than any strategy you bring with you.
The Anatomy of a Roulette Round
Every round of roulette — physical or online, live dealer or RNG — follows the same four-phase sequence. Knowing the rhythm matters less for outcomes than for table etiquette, but it is the foundation everything else sits on.
The Table — Inside vs Outside
The betting layout splits into two areas. Inside bets sit on the numbered grid itself. Outside bets cover the boxes around it. The split looks like a choice between “risky” and “safe” — it is not. Both sides carry the same 2.70% house edge on a European wheel. What changes is variance: how often you win and how big the payouts are when you do.
Inside Bets — Full Reference
Six standard inside bet types exist on a European table. They differ in coverage and payout but share an identical house edge. The choice between them is a variance question, not a value question.
| Bet type | Numbers | Payout | Win % (EU) | Chip placement |
|---|---|---|---|---|
| Straight Up | 1 | 35:1 | 2.70% | Centre of any numbered square |
| Split | 2 adjacent | 17:1 | 5.41% | Line between two adjacent numbers |
| Street | 3 (one row) | 11:1 | 8.11% | Outer edge of a row |
| Corner (Square) | 4 | 8:1 | 10.81% | Centre of a four-number square |
| Six Line | 6 | 5:1 | 16.22% | Edge where two rows meet |
| Trio (EU/FR only) | 3 incl. zero | 11:1 | 8.11% | Intersection of 0 and two numbers |
All probabilities are calculated on a 37-pocket European wheel. To model exact returns at your own stake, use the interactive payout calculator.
Outside Bets — Full Reference
Outside bets cover larger groups in the boxes around the number grid. They win more often than inside bets and pay proportionally less. One detail catches new players regularly: zero is not covered by any outside bet. When zero lands, every outside bet loses — unless La Partage or En Prison is in play.
| Bet type | Numbers | Payout | Win % (EU) |
|---|---|---|---|
| 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% |
Where the House Edge Comes From
The zero pocket is the entire source of the casino’s mathematical advantage in roulette. Payouts are priced as if there are 36 numbers on the wheel — but there are 37 (European) or 38 (American). That extra pocket, averaged across every possible outcome, is the edge.
The practical math: every €100 you wager, the casino expects to keep €2.70. Over 500 spins at €10 per spin (€5,000 total wagered) the expected loss is €135. No betting system changes this; systems redistribute when and how your wins and losses arrive, never the underlying expectation. The deep dive lives in the house edge analysis.
Regional Variants — Why the Wheel Matters
The wrong table will literally double the casino’s advantage. Variant choice outranks any strategy or system decision.
| Variant | Pockets | House edge | Best for |
|---|---|---|---|
| French + La Partage | 37 | 1.35% | Even-money players — lowest edge available |
| European | 37 | 2.70% | All players — global default |
| American | 38 | 5.26% | Avoid if European is on offer |
| Triple Zero | 39 | 7.69% | Never — always pick a standard wheel |
Frequently Asked Questions
Is there a limit to how much I can bet on a single position?
Yes. Every table has a minimum and maximum per position, and these limits matter most for progression systems. A Martingale starting at €100 hits a €50,000 table cap after only nine consecutive losses on an even-money bet. Always check both limits before sitting down — and model your worst case with the payout calculator.
Can the dealer influence where the ball lands?
In regulated land-based casinos and licensed live dealer rooms, the equipment is audited regularly to prevent any kind of bias. Wheels are tested and replaced on a maintenance schedule. Randomness is the legal requirement. “Dealer signature” — the theoretical idea that a consistent spin technique could produce predictable landing zones — is covered in our advantage play breakdown.
What is the En Prison rule?
En Prison is a French rule that applies only to even-money bets when zero lands. Instead of losing, the bet is “imprisoned” for one more spin. If the next spin wins, the original stake comes back — no profit. If it loses, the stake is gone. Mathematically identical to La Partage: both cut the edge on even-money bets from 2.70% to 1.35%.
Does the green zero count as even or odd?
Neither. Zero is a separate category — not red, not black, not odd, not even, not high, not low. That is precisely why every outside bet loses when zero lands, and precisely where the house edge lives. La Partage on a French table is the only mechanic that gives anything back.
How do roulette strategies interact with the rules?
Betting systems operate inside the ruleset — they never change the math. Table limits constrain progression systems like Martingale and Fibonacci. The variant choice sets the base edge. La Partage benefits even-money strategies specifically. No system produces a long-term advantage. The full side-by-side comparison sits in the strategy index.
What is the Five Number Bet on American roulette?
The Five Number Bet covers 0, 00, 1, 2 and 3 — only available on American wheels. It pays 6:1. It is the only standard bet in roulette with a worse edge than its own table: 7.89% vs the 5.26% on every other American wager. Nobody recommends it. Cover the zero pockets with separate straight-up bets on 0 and 00 if you must.