Understanding the House Edge: Why the Casino Always Wins
Updated Written by Jonathan Williams
What Is the House Edge?
The house edge explained simply is the mathematical advantage that every casino holds over players on every game. It is expressed as a percentage and represents the average amount the casino expects to keep from each bet over time. A 2% house edge means that for every €100 wagered, the casino expects to retain €2 on average.
This does not mean you will lose exactly 2% every session. Short-term results vary widely because of variance — you might win big one night and lose the next. But over thousands of bets, the actual results converge toward the theoretical edge. This is the law of large numbers, and it is how casinos guarantee long-term profitability regardless of individual outcomes.
House Edge vs Return to Player
House edge and Return to Player (RTP) are two sides of the same coin. If a game has a 4% house edge, it has a 96% RTP — meaning that for every €100 wagered, €96 is returned to players on average and €4 goes to the casino.
Our guide on slot RTP covers this concept in detail for slot machines specifically. The key takeaway is that RTP is a long-term statistical average, not a guarantee for any individual session. You can win more than the RTP suggests in one session and lose more in the next. Understanding this helps you set realistic expectations about bankroll management and session outcomes.
House Edge by Game
Table Games
| Game | Bet Type | House Edge |
|---|---|---|
| Blackjack | Basic strategy | 0.5–1.0% |
| Baccarat | Banker bet | 1.06% |
| Baccarat | Player bet | 1.24% |
| Craps | Pass / Come | 1.41% |
| European Roulette | Any outside bet | 2.70% |
| American Roulette | Any outside bet | 5.26% |
| Baccarat | Tie bet | 14.36% |
Blackjack offers the lowest house edge of any casino game when played with basic strategy. The edge increases significantly when players deviate from optimal play, which is why learning the rules matters.
Slots
Online slots typically have a house edge between 2% and 6%, corresponding to an RTP of 94–98%. The exact figure depends on the game. High-volatility slots may have the same RTP as low-volatility ones, but the distribution of wins is very different — high-volatility games pay out less frequently but in larger amounts.
Unlike table games, you cannot influence the house edge on slots through strategy. Every spin is determined by a random number generator, and the outcome is entirely independent of previous spins.
How the House Edge Affects Your Sessions
The house edge works on every bet, not just your initial deposit. If you deposit €100 and wager it once on a game with a 2% edge, your expected loss is €2. But if you wager that €100 repeatedly — betting, winning some, losing some, and re-betting — the edge compounds against each wager.
This is called the “churn” or “handle.” A player who deposits €100 but places €1,000 in total bets during a session faces an expected loss of €20 (2% of €1,000), not €2. The longer you play, the more the house edge grinds down your bankroll. This is exactly why setting session limits and deposit limits matters.
Why Understanding the House Edge Matters
Knowing the house edge protects you in three important ways:
- It sets realistic expectations. Gambling is entertainment with a cost, not an income source. Expecting to lose over time is not pessimism — it is mathematics.
- It helps you choose games wisely. A player who understands the difference between a 1% and a 5% house edge can make more informed decisions about where to spend their time and money.
- It prevents chasing losses. If you understand that losses are the expected outcome over time, you are less likely to chase them with bigger bets. Chasing losses is one of the clearest responsible gambling warning signs.
This is also why our casino guides emphasise understanding game mechanics before you play. The more you know, the better your decisions.
Can You Beat the House Edge?
In the long run, no. The house edge is built into every game and cannot be eliminated through any betting system, strategy, or pattern. Systems like the Martingale (doubling your bet after each loss) do not change the mathematical edge — they only change the distribution of risk, often making catastrophic losses more likely.
What you can do is minimise the edge by:
- Playing games with lower house edges (blackjack with basic strategy, baccarat banker bet)
- Avoiding high-edge bets (roulette side bets, keno, baccarat tie bet)
- Using deposit limits to control how much you wager in total
- Setting session time limits to reduce the churn effect
- Treating any winnings as a bonus, not an expectation
Conclusion
The house edge is not a conspiracy — it is the business model that makes casinos possible. Understanding it does not take the fun out of gambling. It simply helps you play with realistic expectations, make smarter choices about which games to play, and keep your spending within boundaries you have chosen for yourself.
Frequently Asked Questions
Does the house edge mean I will always lose?
Not in every session. The house edge is a long-term average. In the short term, variance means you can win or lose more than the edge predicts. But over hundreds or thousands of bets, your results will trend toward the expected loss.
Is the house edge the same as the odds of winning?
No. The odds of winning describe the probability of a single bet succeeding. The house edge describes the overall cost of playing over time. You can win individual bets and still face a mathematical disadvantage overall.
Do online casinos have a different house edge than land-based casinos?
Online slots often have a lower house edge (higher RTP) than land-based machines because online operators have lower overhead costs. Table game house edges are typically the same in both settings because they are determined by the game rules, not the venue.
Can a casino change the house edge on a game?
Casinos can choose which game variants to offer, and different variants have different house edges. For example, a casino might offer European roulette (2.70% edge) or American roulette (5.26% edge). The house edge of a specific game variant is fixed by its rules and cannot be altered mid-play.
How does the house edge relate to responsible gambling?
Understanding the house edge is a foundation of responsible gambling. It reminds you that gambling costs money over time, just like any other form of entertainment. Knowing this helps you budget appropriately, avoid chasing losses, and use tools like deposit limits to stay in control.
