The definition, without the hedging
The house edge is the share of every wager a casino keeps on average over a very large number of bets. A game with a 4% house edge returns 96 cents of every dollar staked across millions of rounds and keeps four.
It is expressed as a percentage of turnover, not of your deposit, and that distinction is where most players misjudge it. Stake 100 dollars ten times over an evening and you have wagered 1,000 dollars, not 100. At a 4% edge the expected cost of that session is 40 dollars, not four.
This is also why session length matters more than stake size for total cost. A small bet repeated often costs more than a large bet placed once.
House edge and RTP are the same number
Return to player is the complement: RTP plus house edge equals 100%. A 96% RTP game has a 4% edge. A 99% RTP game has a 1% edge.
Operators quote RTP because a large number sounds generous. We publish both, and lead with the edge, because a 3% difference in RTP is a 75% difference in what the game costs you. Framed as 96% against 99%, the gap looks marginal. Framed as four dollars against one, it is not.
| Casino | Games | Average RTP | House edge | Cost per $100 wagered |
|---|---|---|---|---|
| Duelbits | 272 | 96.33% | 3.67% | $3.67 |
| Rainbet | 315 | 96.32% | 3.68% | $3.68 |
| Shuffle | 286 | 96.31% | 3.69% | $3.69 |
| Bcgame | 218 | 96.27% | 3.73% | $3.73 |
| Gamdom | 205 | 96.26% | 3.74% | $3.74 |
| Stake | 1377 | 96.17% | 3.83% | $3.83 |
House edge is 100 minus the average reported RTP, so the cost column is what the maths implies you pay per $100 staked over the long run. It is not a session prediction, and it excludes any rakeback the casino returns.
Typical edges by game
Roughly, and before any variation in rules:
Blackjack with basic strategy: 0.5% or less. The lowest edge on a casino floor, and the only major game where your decisions change it.
Baccarat, banker bet: around 1.06%.
Craps, pass line: around 1.41%.
European roulette, single zero: 2.7%. American roulette with a double zero doubles that to 5.26%, which is the clearest example of a rule change costing a player real money.
Online slots: typically 2% to 6%, clustering near 4%.
Keno and most side bets: often above 10%, sometimes far above.
The pattern: games requiring a decision tend to charge less than games that do not.
What the edge does not tell you
It says nothing about a single session. Variance dominates over any realistic number of bets, which is precisely why casinos can offer games where players regularly win.
Two games at identical edge can also feel completely different. A low-volatility slot pays small amounts often; a high-volatility one pays rarely and larger. Same expected cost, entirely different experience and entirely different bankroll requirement.
And the edge assumes you play the game correctly. In blackjack, poor decisions add several percentage points to the theoretical figure, which means the published edge describes a player you might not be.
How to use this
Compare the edge, not the bonus. An operator returning part of its edge on every bet changes your cost permanently; a welcome offer changes it once and usually costs more to unlock than it hands over. Our page on cost of play ranks operators on this basis, and wagering requirements does the arithmetic on the alternative.
Then check the build. The same game can run at different returns at different casinos, and the gaps we found in same game, different RTP reach two percentage points, which dwarfs the difference between operators in any overall ranking.