Games · Roulette · How to play & odds
How to play roulette — and the real odds
Roulette is the simplest game on the floor to play and one of the most misunderstood to understand. This guide covers every bet and what it pays, what the house edge actually is, and why the wheel always wins in the end — with the numbers computed by our own verified engine.
What this guide covers
We'll start from the wheel itself, walk through every inside and outside bet with its payout and true odds, then get to the part most guides gloss over: what the odds actually are, why nearly every bet on the table shares the exact same house edge, and why no betting system can beat it. Every odds figure here comes from our own analytic solver, not a rule of thumb.
1. How roulette works
A roulette wheel is divided into numbered pockets. You place chips on a betting layout, the dealer spins the wheel and drops a ball, and wherever the ball lands decides every bet on the table. That's it — there are no decisions after the spin, and nothing you did on previous spins changes the next one.
There are two wheels you'll encounter, and the difference between them is one pocket:
- European — 37 pockets: 0 and 1–36. A single green zero.
- American — 38 pockets: 0, 00, and 1–36. A second green zero (the double zero).
That extra 00 doesn't change any payout — but it nearly doubles the house edge. When you can choose, always choose the European (single-zero) wheel. We break the comparison down bet-by-bet in American vs European Roulette.
2. The bets & their payouts
Roulette bets come in two families. Inside bets sit on the numbers themselves — riskier, with bigger payouts. Outside bets sit around the edge on big groups of numbers — safer, with smaller payouts. Here's the full menu, with the win chance and true odds on a European wheel:
Inside bets
| Bet | Covers | Pays | Win chance | True odds |
|---|---|---|---|---|
| Straight up — a single number | 1 | 35:1 | 2.70% | 36 to 1 |
| Split — 2 adjoining numbers | 2 | 17:1 | 5.41% | 17.50 to 1 |
| Street — 3 numbers in a row | 3 | 11:1 | 8.11% | 11.33 to 1 |
| Corner — 4 numbers in a square | 4 | 8:1 | 10.81% | 8.25 to 1 |
| Six line — 6 numbers (two rows) | 6 | 5:1 | 16.22% | 5.17 to 1 |
Outside bets
| Bet | Covers | Pays | Win chance | True odds |
|---|---|---|---|---|
| Red / Black — 18 numbers of a colour | 18 | 1:1 | 48.65% | 1.06 to 1 |
| Odd / Even — 18 numbers | 18 | 1:1 | 48.65% | 1.06 to 1 |
| 1–18 / 19–36 — 18 numbers (low / high) | 18 | 1:1 | 48.65% | 1.06 to 1 |
| Dozen — 12 numbers (1st/2nd/3rd) | 12 | 2:1 | 32.43% | 2.08 to 1 |
| Column — 12 numbers (a vertical column) | 12 | 2:1 | 32.43% | 2.08 to 1 |
Win chance and true odds are for the European wheel (37 pockets); on the American wheel each is slightly worse because of the extra pocket. True odds is what a fair bet would pay — notice it's always a little higher than the actual payout. That small gap, on every bet, is the house edge.
3. The odds: house edge & RTP
Two numbers describe a game's math. The house edge is the casino's long-run cut — the share of each bet you'd expect to lose on average. RTP (“return to player”) is just the flip side: RTP = 100% − house edge.
For standard roulette bets the edge is fixed by the wheel:
| Wheel | House edge | RTP |
|---|---|---|
| European (single zero) | 2.70% | 97.30% |
| American (double zero) | 5.26% | 94.74% |
| American top line (0-00-1-2-3) | 7.89% | 92.11% |
4. Why (almost) every bet has the same edge
Look back at the bets table: a straight-up number and an even-money red bet feel completely different, yet both carry the same 2.70% edge. That's not a coincidence. Each payout is set so the bet would be perfectly fair if the wheel had no zeros — a straight-up number would pay its true 36-to-1, red would pay even money against 18 ways to win and 18 to lose. The green zero (or two) is exactly what tips every bet in the house's favor, by the same proportion.
So switching from single numbers to red, or spreading chips across a dozen, doesn't change your edge at all — it only changes how often you win and how big the swings are. Covering more of the layout raises your hit rate but lowers your payout in exact lockstep; the house's cut never moves. You can prove this to yourself on the table: add bets and the combined edge readout stays glued to 2.70% (or 5.26% on the American wheel).
5. Betting systems & why they don't work
You'll see countless “systems” promising to beat roulette — the Martingale (double your bet after every loss), the Fibonacci, the D'Alembert, and others. They all share one fatal flaw: the wheel has no memory. Each spin is independent, with the same 2.70%–5.26% edge, no matter what came before. No pattern of bet sizes can turn a sum of negative-expectation spins into a positive one — the math simply doesn't allow it.
The Martingale feels like it works because it wins small amounts often — until a losing streak (which will happen) hits the table limit or your bankroll and wipes out every prior gain at once. “Red is due after five blacks” is the gambler's fallacy: the next spin is still a coin-flip-ish ~48.6%, the same as always. Systems change the shape of your wins and losses, never the average.
6. Bankroll & variance
Roulette's appeal is its swings, and they're real: a single straight-up number hits only ~2.7% of the time but pays 35:1, so sessions are streaky and unpredictable. That spread around the average is variance — and it's what you actually feel at the table, far more than the slow grind of the edge.
Which is why bankroll management matters more than any betting trick. Play with money you can afford to lose, keep each bet small relative to your bankroll so a normal cold streak can't bust you, and treat it as paid entertainment — the expected cost per spin is your bet times the edge. Our Simulate tab plots the bankroll trajectory over thousands of spins so you can see exactly how wide those swings get around the downward drift.
7. Next steps
How this simulation works
- Rules modeled
- Single-zero (European, 37 pockets) and double-zero (American, 38) wheels with standard payouts — straight 35:1, split 17:1, street 11:1, corner 8:1, six-line 5:1, top line 6:1, column/dozen 2:1, even-money 1:1. No La Partage / En Prison rules.
- Assumptions
- Win chance and true odds shown are for the European wheel; the American wheel is slightly worse per the extra pocket. Each spin is independent and uniform over the wheel's pockets.
- Mathematical basis
- Every odd and edge is computed by our roulette analytic solver (house edge = (N − w·(payout+1)) ÷ N), the displayed source of truth, at build time. Reference edges: European 2.70% (1/37), American 5.26% (2/38), American top line 7.89% (3/38).
- Engine version
- roulette engine 1.0
- Validation
- Unit-tested (every bet's edge, the top-line special case, exact combination distributions, seeded reproducibility, 100k-spin convergence, settlement, validation).
- Last reviewed
- Independently reviewed for math and code correctness; every reported finding was addressed and regression-tested.