House Edge Explained
The house edge is the mathematical advantage that every casino game is designed to give the operator over time. It is expressed as a percentage of each bet that the casino expects to retain as profit across millions of rounds. The house edge does not mean you will lose that percentage in any individual session; it describes the long-run statistical outcome across all players playing the game.
Where the House Edge Comes From
In roulette, the house edge on a European wheel comes from the single green zero pocket. There are 37 pockets (1–36 plus 0). A winning straight bet pays 35:1, but there are 37 equally likely outcomes. The true odds should be 36:1 to break even. The 1-in-37 discrepancy is 2.7%, which is the house edge. Every casino game has a similar structural advantage built into the payout ratios.
House Edge by Game: Complete Reference
| Game / Bet | House Edge | Expected Loss per $1,000 Wagered |
|---|---|---|
| Blackjack (perfect basic strategy) | 0.5% | $5 |
| Video Poker: Jacks or Better (full pay) | 0.46% | $4.60 |
| Baccarat: Banker bet | 1.06% | $10.60 |
| Baccarat: Player bet | 1.24% | $12.40 |
| Craps: Pass Line with 3-4-5x odds | 0.37% | $3.70 |
| European Roulette | 2.70% | $27 |
| French Roulette (La Partage) | 1.35% | $13.50 |
| American Roulette | 5.26% | $52.60 |
| Online Slots (average) | 4% | $40 |
| Baccarat: Tie bet | 14.36% | $143.60 |
Why the House Edge Compounds Over Time
At a 5% house edge, playing 100 rounds at $10 per round ($1,000 total wagered) produces an expected loss of $50. But the actual money you have available decreases with each loss, and each new bet is sized from your diminishing bankroll. This compounding effect means that the longer you play a negative-expectation game, the more likely you are to experience the expected statistical loss. Short sessions have high variance; long sessions converge toward the mathematical expectation.
Can betting systems overcome the house edge?
No. Betting systems (Martingale, Fibonacci, Labouchère) change the distribution of wins and losses but do not alter the expected return. The Martingale system, for example, produces frequent small wins at the cost of occasional catastrophic losses, but the average outcome over time is identical to flat betting at the same house edge.