updated regularly – latest review: October 2026
The house edge is the percentage of every bet that a casino expects to keep over the long run. Every casino game has one, and it is the reason casinos make money even though players win plenty of individual bets. Understanding it helps you compare games, judge bonus offers and set realistic expectations before you play.
What the house edge means
If a game has a house edge of 2.7%, the casino expects to keep, on average, £2.70 of every £100 wagered on it. That is an average over a huge number of bets, not a prediction for your session. In one evening you might win, lose or break even; the edge describes what happens over thousands of rounds.
It is closely related to return to player (RTP), which you will see quoted on slots. The two add up to 100%, so a slot with a 96% RTP has a 4% house edge. Our guide to RTP in slots explains how RTP is measured.
The edge on popular casino games
- European roulette: 2.70%. The single green zero is what gives the casino its edge, since every bet pays slightly less than its true odds.
- American roulette: 5.26%. The extra double zero almost doubles the edge, so European roulette is the better choice when both are available.
- Blackjack: often under 1% if you follow basic strategy, but it depends on the table rules, such as how many decks are used and what blackjack pays.
- Baccarat: about 1.06% on the banker bet (after commission), about 1.24% on the player bet and over 14% on the tie bet.
- Slots: varies by game. Many slots publish an RTP in the mid-90s, which means a house edge of roughly 3% to 6%.
Why it matters for bonuses
The edge is the key to working out whether a casino bonus is worth claiming. If an offer asks you to wager £100 on slots with a 96% RTP, the expected cost of that wagering is about £4. If the bonus is worth more than that, the offer has positive expected value; if not, you are likely to lose more than you gain.
This is why bonus terms that restrict you to low-RTP games, or that need a lot of wagering, can turn a generous-looking headline into a poor deal. Our guides to wagering requirements and casino bonuses go through the maths step by step.
Can you beat the house edge?
Not in the long run, on standard casino games. Betting systems such as doubling your stake after each loss do not change the maths; they only change how your wins and losses are spread out, and they can lead to very large stakes very quickly. Blackjack strategy can reduce the edge but not remove it.
The realistic approach is to choose games where the edge is lower, play within a budget you are happy to spend, and treat any win as a bonus rather than an expectation.
Quick reference
- House edge plus RTP equals 100%.
- A lower edge means you lose less on average per pound wagered.
- Choose European over American roulette, and banker over tie in baccarat.
- Use the edge to estimate the cost of clearing a bonus before you opt in.
18+. Gambling should be fun. Set a budget you can afford to lose, and if it stops being fun, visit BeGambleAware.org or call the National Gambling Helpline on 0808 8020 133.
