Roulette Basics: American vs. European Wheels and Bet Types
Roulette is often introduced as the simplest game on the casino floor — pick a number or a color, watch the wheel spin, see what happens — and mechanically that's true. What rarely gets explained clearly is that "roulette" isn't actually one game with one house edge. Two wheels that look almost identical at a glance produce a meaningfully different cost to play, and the difference comes down to a single extra pocket that most new players never notice until someone points it out.
In this guide
The one difference that matters most: 37 pockets or 38
A European roulette wheel has 37 pockets: the numbers 1 through 36, plus a single green 0. An American wheel has 38: the same 1 through 36, plus both a green 0 and a green 00. That single extra pocket is the entire reason American roulette is a worse game mathematically, because every payout on the table is still calculated as if there were only 36 non-zero numbers to divide among. Adding a second zero pocket increases the house's edge without changing what any winning bet pays out.
| Wheel | Pockets | House edge (standard bets) |
|---|---|---|
| American | 38 (1-36, 0, 00) | 5.26% |
| European | 37 (1-36, 0) | 2.70% |
| European with La Partage | 37 (1-36, 0) | ~1.35% on even-money bets only |
That gap is enormous by casino-game standards — nearly double the house edge for what looks like a cosmetic difference in the wheel's layout. If a casino floor (or an online casino's game lobby) offers both versions, choosing the European wheel is close to a strictly better decision every time, all else being equal.
Inside bets: betting directly on numbers
Inside bets are wagers placed on or touching specific numbers on the betting layout, and they pay more because they're less likely to hit. On a European wheel, here's what each pays and its true odds against:
| Bet | Numbers covered | Payout | Win probability (European) |
|---|---|---|---|
| Straight up | 1 number | 35 to 1 | 2.70% |
| Split | 2 adjacent numbers | 17 to 1 | 5.41% |
| Street | 3 numbers in a row | 11 to 1 | 8.11% |
| Corner | 4 numbers in a block | 8 to 1 | 10.81% |
| Six line | 6 numbers (two rows) | 5 to 1 | 16.22% |
Notice that every single one of these bets carries the identical 2.70% house edge on a European wheel (or 5.26% on American) once you run the math, regardless of which specific inside bet you choose. Roulette is unusual among casino games in that nearly every bet on the table carries the same edge — the payout odds are simply scaled to match each bet's true probability, so no combination of inside bets gives you a mathematical advantage over another.
Outside bets: betting on groups
Outside bets cover larger groups of numbers and pay less as a result, but they hit far more often, which is why they're the more popular choice for players who want a longer, steadier session rather than the big swings of a straight-up number bet.
- Red or black: pays even money (1 to 1), covers 18 numbers.
- Odd or even: pays even money, covers 18 numbers (0 and 00 are neither).
- Low (1-18) or high (19-36): pays even money, covers 18 numbers.
- Dozens (1-12, 13-24, 25-36): pays 2 to 1, covers 12 numbers.
- Columns: pays 2 to 1, covers 12 numbers arranged in a vertical column on the layout.
The even-money bets — red/black, odd/even, high/low — are the ones that matter most for the rules covered next, since they're the only bets eligible for La Partage or en prison at most casinos that offer those rules.
La Partage and en prison: the rules that cut the edge further
Some European-wheel tables, more commonly found online and at select physical casinos, add a rule that specifically softens the blow when the ball lands on 0. Under La Partage ("shared," in French), a player who has an even-money bet working when 0 hits gets half of that wager back instead of losing the whole thing. Under the related en prison rule, instead of returning half the bet immediately, the wager stays "imprisoned" for one more spin — if it wins on that next spin, the original stake is returned in full with no additional payout; if it loses, the house keeps it.
A worked example: the real cost of 100 spins
Say you bet $10 on red for 100 spins. On a standard American wheel with a 5.26% house edge, your expected loss over that stretch is roughly $10 x 100 x 0.0526, or about $52.60. Move to a European wheel with no special rule and a 2.70% edge, and the same session's expected loss drops to about $27. Add La Partage on that European table, cutting the effective edge on the red bet to roughly 1.35%, and the expected loss falls again to about $13.50 — less than a quarter of what the same $1,000 in total action would have cost you on the American wheel.
None of this changes what happens on any individual spin — the ball doesn't know or care which wheel it's on, and any given spin can win or lose regardless of house edge. What changes is the long-run average across many spins, which is exactly why the wheel you choose matters more the longer you plan to play.
Myths worth retiring before you sit down
Roulette attracts more betting folklore than almost any other casino game, and most of it doesn't survive contact with how the wheel actually works. A few worth naming directly: a number that hasn't hit in a while is not "due" — each spin is an independent event with no memory of previous results, so a wheel that hasn't landed on 17 in forty spins is exactly as likely to land on 17 next spin as it was on the first spin of the night. Betting systems like the Martingale (doubling your bet after every loss to "guarantee" recovering losses on the next win) don't change the underlying house edge either; they change the shape of your risk, trading a higher chance of a small win for a smaller chance of a catastrophic loss when a long losing streak meets a table betting limit or your own bankroll ceiling. And a "hot" or "cold" table has no physical basis on a properly maintained, regularly inspected wheel — the perception comes entirely from how streaks look in hindsight, not from any real bias in the equipment. For more on how roulette's house edge stacks up against other table games, see our house edge guide, and for general session budgeting, see our bankroll management guide.
Frequently asked questions
Is European roulette always better than American roulette?
For the player, essentially yes on the math alone — the lower house edge applies to every bet on the table, not just certain ones. The only reason to choose American roulette is availability, since not every physical casino floor offers a European wheel.
Do all roulette bets really carry the same house edge?
On a standard wheel with no special rules like La Partage, yes — every bet from a single straight-up number to the largest outside bet carries the identical house edge for that wheel type, because payouts are scaled to match each bet's true probability of hitting.
What's the difference between La Partage and en prison?
La Partage immediately returns half your even-money bet if 0 hits. En prison instead holds your full original bet for one more spin — you get it back in full if that next spin wins, or lose it if that spin loses. Both apply only to even-money outside bets and produce a similar long-run benefit to the player.
Can a betting system like Martingale beat the house edge over time?
No. Progressive betting systems change how your losses and wins are distributed across a session, but they don't change the wheel's underlying probabilities, so the house edge stays exactly the same over the long run regardless of how you size your bets from spin to spin.