What is house edge in roulette
House edge in roulette is the mathematical advantage the casino holds on every bet placed at the table, expressed as a percentage of the wager. It comes from the layout of the wheel and the way payouts are set relative to the true odds of a number coming up. The edge does not predict what happens on any single spin — it describes the average result the casino expects over a very large number of bets.
Where the edge comes from
Roulette pays out as if the wheel had fewer numbers than it actually does. A single number bet on a wheel with 37 or 38 pockets pays 35 to 1, but the real probability of hitting one number is 1 in 37 or 1 in 38. That gap between the true odds and the payout odds is the source of the house edge. It applies uniformly to inside bets (single numbers, splits, corners) and outside bets (red/black, odd/even, columns, dozens) alike, because the payout structure is built around the same imbalance.
Why the number is a percentage, not a fixed sum
The edge is quoted as a percentage of each wager rather than a fixed amount, because it scales with how much is staked. A £10 bet and a £100 bet carry the same percentage disadvantage; the higher stake simply multiplies the expected loss in absolute terms over time. This is why the edge is useful for comparing games or bet types, but tells nothing about the outcome of an individual spin, which remains random and independent of previous results.
Related: House Edge in Craps: Why It Changes With Every Bet and How Does House Edge Work: 9 Things to Understand.
Why the edge is not the same on every wheel
Roulette house edge depends on the roulette variant and the specific table rules in use. A wheel with a single zero pocket has a different edge from one with a double zero, because the extra pocket changes the probability of any given number without changing the payout. Some tables add further pockets or rule variations, which shift the edge again. Different roulette types can have different house edges, so a blanket figure for "roulette" without naming the variant is incomplete.
Rules that adjust the edge on European tables
Certain single-zero tables include additional rules that reduce the edge on even-money bets specifically (red/black, odd/even, high/low), applied only when the ball lands on zero. Where such a rule is in force, it either returns half the stake or carries the bet forward to the next spin instead of losing it outright. These rules do not apply to inside bets and are not present on every table, so the exact terms should be confirmed on the table's own rules display or the operator's official information before play.
Table: how variant affects the edge
| Wheel type | Zero pockets | Effect on house edge |
|---|---|---|
| Single-zero wheel | 1 | Lower edge than double-zero wheels, on both inside and outside bets |
| Double-zero wheel | 2 | Higher edge across all bet types, due to the extra pocket |
| Single-zero with reduced-edge rule on even-money bets | 1 | Lower edge specifically on even-money outside bets when the rule applies |
| Triple-zero or other added-pocket variants | 3 or more | Higher edge than both single- and double-zero wheels |
Exact percentage figures are not listed here because they depend on the paytable and rule set of the specific game in play; these are printed in the game's own information screen or rules sheet and should be checked there directly.
What the edge does and does not mean in practice
The edge describes the casino's expected long-run profit across many bets from many players, not a schedule of losses for one person's session. A player can win on any given spin, series of spins, or entire session, because each spin is an independent event with no memory of what came before. No betting progression, timing method, or pattern-tracking approach changes the underlying probabilities or the built-in edge; the edge is a property of the game's rules, not of how or when a bet is placed. Roulette, like other casino games, is intended for adult players, and understanding the edge is a matter of realistic expectation rather than a way to overcome it.
Frequent questions
Does the house edge mean a loss on every spin?
No. It is a long-run average calculated across a large number of bets, not a guarantee applied to any single spin. Short-term results can vary widely in either direction from what the edge would suggest.
Can betting systems reduce the house edge?
No betting system changes the probabilities built into the wheel or the payout table. Progressive staking patterns change how quickly money moves between player and casino, but not the underlying edge itself.
Why do some roulette tables feel more generous than others?
Different roulette types can have different house edges because of the number of zero pockets and any additional rules applied to even-money bets. A table with fewer zero pockets or a favourable zero rule carries a lower edge than one without.
Where can the exact house edge for a specific game be found?
The precise figure depends on the variant and rule set in use, and is not identical across all roulette games. It is listed in the game's paytable or rules information, or can be confirmed directly with the operator running the table.