This guide explains where the edge comes from, how European and American wheels differ, and why no amount of clever betting can make it disappear. To see the edge grind a balance down in real time, try our roulette simulator.
What "house edge" actually means
The house edge is the average percentage of each bet the casino expects to keep over the long run. A 2.70% edge means that for every 100 you wager, you should expect to lose 2.70 on average, not on any single spin, but across thousands of them.
It comes entirely from one design trick: the payouts are slightly smaller than the true odds.
Where the 2.70% comes from
A European wheel has 37 pockets: numbers 1 through 36, plus a single green 0. Bet on a single number and your chance of winning is 1 in 37. Fair odds would pay 36 to 1, so that over 37 spins you break even. The casino pays only 35 to 1.
That missing unit is the edge. Worked out:
- Win once in 37 spins: you gain 35.
- Lose 36 times: you lose 36.
- Net over 37 spins: −1 unit on 37 units staked = −1/37 = −2.70%.
Here's the elegant, ruthless part: every bet on a European wheel carries the same 2.70% edge. Red/black, dozens, single numbers, corners, it doesn't matter. The zero is what tips every wager slightly in the casino's favour, and it does so uniformly.
European vs American roulette
The American wheel adds a second green pocket, 00, for 38 pockets total. Everything else looks identical, including the payouts, but that one extra pocket nearly doubles the edge:
| Wheel | Pockets | House edge | Loss per 100 wagered |
|---|---|---|---|
| European (single zero) | 37 | 2.70% | 2.70 |
| American (double zero) | 38 | 5.26% | 5.26 |
The payouts didn't change, but your chance of hitting any given number dropped from 1/37 to 1/38 while the casino still pays 35:1. The rule of thumb is simple: always choose a single-zero wheel if you have the option. Over a long session, the American wheel costs you roughly twice as much.
On American wheels, the five-number "basket" bet (0, 00, 1, 2, 3) is even worse, carrying a 7.89% edge. It's the one bet to avoid entirely.
La partage and en prison: when the edge gets cut in half
Some European and French tables soften the blow on even-money bets (red/black, odd/even, high/low) with two rules:
- La partage: if the ball lands on zero, you lose only half your even-money bet instead of all of it.
- En prison: if zero hits, your even-money bet is "imprisoned" for one more spin. Win it back and you lose nothing.
Either rule cuts the house edge on those even-money bets from 2.70% down to 1.35%, the best deal in the entire game. If you see a French table with la partage, even-money bets there are the most player-friendly wager roulette offers.
Why no strategy beats the edge
This is the question every system promises to answer, and the answer is always the same: it can't. Betting systems change how you bet, never the underlying odds of a spin. The wheel has no memory, so each spin's expected value is fixed at −2.70% regardless of what came before.
You can rearrange your bets to make wins feel more frequent (the Martingale) or to chase hot streaks (the Paroli), but the sum of everything you wager still bleeds 2.70% on average. A negative-expectation game cannot be turned positive by changing the order or size of bets.
The only things genuinely under your control are:
- Which wheel you play (single zero beats double zero).
- Whether the table offers la partage (halves the edge on even-money bets).
- How much you wager in total, since the edge applies to turnover, not to your starting bankroll.
That last point is the most important and the most ignored. A player who wagers 10,000 across a night faces an expected loss near 270 on a European wheel, even if their balance bounces up and down many times along the way. It's turnover, not luck, that the edge feeds on.
Frequently asked questions
Is roulette rigged? A fair, properly run wheel isn't rigged in the sense of cheating. It doesn't need to be. The house edge is built openly into the payouts, and that alone guarantees long-term casino profit without any tampering.
Can I win at roulette? In the short term, absolutely, variance means plenty of players walk away ahead on any given night. Over the long run, the edge makes a sustained profit mathematically impossible without an outside advantage like a biased wheel.
Which roulette bet has the best odds? On a French table with la partage, even-money bets carry just a 1.35% edge, the lowest in the game. On a standard European wheel, every bet is the same 2.70%, so pick whichever you find most fun.
How is the house edge different from RTP? They're two sides of the same number. RTP (return to player) is what the game pays back: a 2.70% edge means a 97.30% RTP. The casino keeps the difference.
The takeaway
The house edge is roulette in a single number. On a European wheel it's 2.70%, on an American wheel 5.26%, and on a French table with la partage it drops to 1.35% on even-money bets. That edge comes from the green zero paying you slightly less than fair odds, it applies to every bet equally, and no system can remove it.
Knowing the number won't make you win, but it will make you a sharper, more realistic player. Watch it work across hundreds of spins in the roulette simulator, and the abstract percentage turns into a balance you can actually see falling.