House Edge Explained: How Casinos Turn a Profit
Updated on July 11, 2026 by the editorial team
Casinos do not need to cheat to make money. Every game carries a small built-in margin called the house edge, and that margin is how the business stays open while still paying out plenty of winners. This guide explains what the house edge is, how it differs from game to game, and what you can actually do to keep it as low as possible before you place a stake.
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Grasp What the House Edge Really Is
The house edge is the casino's built-in advantage on a game, shown as a percentage of every bet. It is the average slice the operator expects to keep over a very large number of rounds.
Picture a game with a 5% house edge. For every £100 wagered on it across thousands of players and sessions, the casino holds onto about £5 and pays back roughly £95. That £5 is not taken from your bet in one hit. It is the long-run average once you spread the wins and losses of everyone playing across a huge sample.
Here is the part that matters. The edge is a statistical certainty for the casino, not a prediction for you. On any single spin, hand or spin of the wheel, you might double your money or lose the lot. The maths only reveals itself over millions of outcomes, which is exactly why the house never needs luck on its side. Time and volume do the work.
A quick way to picture the difference: think of the edge as the price of playing rather than a fee deducted up front. You pay it gradually, spread across every bet, mostly without noticing. A player who wagers £2,000 across an evening on a game with a 2% edge has, on average, paid about £40 for the entertainment, even if they walk away up or down on the night. That average cost is the number worth watching, because it tells you how far your bankroll will stretch.
Bring the Edge Down Before You Bet
You cannot erase the house edge, but you can shrink the one you face. The choices you make before and during play move the number more than most people realise.
- Pick low-edge games. Blackjack with correct strategy and baccarat's banker bet cost you under 1.5%. American roulette runs at 5.26%. Same evening, wildly different price of admission.
- Learn the right strategy. Blackjack only reaches its best figure when you play every hand by the book. Guesswork can push the edge past 2%.
- Choose the better version. European roulette carries one zero and a 2.7% edge. The American wheel adds a second zero and nearly doubles it. Always take the single-zero table.
- Skip the side bets. Insurance in blackjack, the tie bet in baccarat and most roulette side wagers carry brutal edges, sometimes above 14%. They tempt you with big payouts and quietly cost the most.
- Check the RTP on slots. A 97% slot leaves a 3% edge; a 92% slot triples that to 8%. The figure sits in the game's info screen.
None of this guarantees a win. It simply means more of your money stays in play for longer, which is the whole point if you treat gambling as entertainment with a cost attached.
Compare the House Edge Across Popular Games
Not all games charge the same. The gap between the cheapest and the most expensive is far wider than newcomers expect. The table below lists typical figures at a licensed casino.
| Game | House edge | Notes |
|---|---|---|
| Blackjack (basic strategy) | 0.5% - 1% | Only reaches the low end with perfect play |
| Baccarat (banker bet) | ≈1.06% | Best value bet on the table after commission |
| Video poker | 0.5% - 5% | Depends on pay table and your decisions |
| Craps (pass line) | ≈1.41% | Odds bets behind it lower the effective edge |
| European roulette | ≈2.7% | Single zero across every bet type |
| American roulette | ≈5.26% | The second zero almost doubles the cost |
| Video slots | 3% - 8% | Set by each game's RTP; check the info screen |
| Jackpot slots | 6% - 12% | A slice of every bet feeds the progressive pool |
| Keno | 20% - 30% | Fun to play, one of the most expensive on the floor |
Look at roulette on its own. Two wheels that appear almost identical, yet the American version costs you nearly twice as much per bet. Then glance at keno against blackjack. Same casino, and one game keeps thirty times more of your stake than the other. Where you sit down matters as much as how you play.
Tell the House Edge and RTP Apart
These two terms describe the same coin from opposite sides, and mixing them up is common.
RTP, or Return to Player, is the share of all wagered money a game pays back over the long run. House edge is what it keeps. Add them together and you always land on 100%. A slot advertised at 96% RTP has a 4% house edge. A blackjack game with a 0.5% edge returns 99.5% to players. Once you see them as two halves of the same total, the maths stops being confusing.
Which one you meet usually depends on the game. Slot and table-game info screens tend to quote RTP, framing it as a positive return figure. Guides and strategy articles lean on house edge, because it makes the cost of playing easier to compare. Both tell you the same thing. If a review lists a 3% house edge and a slot lists 97% RTP, they are describing identical value.
One warning applies to both numbers. They are long-run averages built into the game's design, not a forecast for your session. A 96% slot will not "owe" you £96 after you feed it £100 tonight. Variance around that average is enormous over a short stretch, and that swing is exactly where the fun and the risk both live.
Volatility is the piece that ties it together. Two slots can share a 96% RTP and a 4% edge yet feel nothing alike. A high-volatility game pays rarely but big, so your balance lurches up and down. A low-volatility game trickles out small wins that keep you spinning longer. The edge stays identical in both cases. If you want a session to last on a modest budget, low volatility paired with a strong RTP gives you the most play for your money.
Common Questions About the House Edge
Does a low house edge mean I will win?
No. A low edge means the game costs less to play over the long run, so more of your bankroll survives across many sessions. Any single session can still end in a loss or a win regardless of the figure. The edge shapes averages, not individual results.
Which casino game has the lowest house edge?
Blackjack played with correct basic strategy usually holds the lowest figure, often between 0.5% and 1%. Baccarat's banker bet sits close behind at around 1.06%. Both reward disciplined play far more than luck-based games like keno or jackpot slots.
Can the casino change the house edge on a game?
Not during play. The edge is fixed by the game's rules and, for slots, by the RTP version the operator installs. That figure stays constant, which is why checking a game's info screen before you bet tells you exactly what you are paying.
Why do slots have a higher edge than blackjack?
Slots run purely on chance with no decisions to optimise, so the design bakes in a wider margin, typically 3% to 8%. Blackjack lets skilled play cut the edge close to zero, which is why strategy-based games reward the effort of learning them.
Is the house edge the same as the odds of winning?
No. Odds describe your chance of winning a single bet. The house edge measures how much the casino keeps on average across all outcomes, including the size of payouts. A bet can win often yet still carry a high edge if the payout is stingy.
Keep your stakes to money you can afford to lose, set a budget or time limit before you start, and treat every session as paid entertainment rather than income. If gambling stops feeling like fun, free support is available through BeGambleAware and GamCare. Revolute casino operates under a Curaçao licence. To go deeper, see how random number generators keep every outcome fair and how our payment methods handle deposits and withdrawals.
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