What Is the House Edge?
The house edge is the mathematical advantage that a casino holds over players on any given game or bet. It's expressed as a percentage and represents the average amount of each bet the casino expects to retain over the long run.
For example, a house edge of 5% means that for every $100 wagered over many bets, the casino expects to keep $5 on average. This doesn't mean you'll lose exactly 5% every session — short-term results vary widely — but the house edge determines outcomes over thousands of rounds.
How Is the House Edge Created?
Casinos build their edge into game rules in various ways:
- Payout rates below true odds: In roulette, a single number pays 35:1, but the true odds on a double-zero wheel are 37:1.
- Rules that favor the dealer: In blackjack, you bust first — even if the dealer also busts on the same round.
- Fixed paytables: Slot machines and video poker games pay out less than the total probability of winning combinations would suggest at true odds.
House Edge by Game
| Game | Approximate House Edge |
|---|---|
| Blackjack (basic strategy) | 0.5% – 1% |
| Baccarat (Banker bet) | ~1.06% |
| Craps (Pass Line bet) | ~1.41% |
| European Roulette | ~2.7% |
| American Roulette | ~5.26% |
| Slots (varies widely) | 2% – 15% |
| Keno | 20%+ |
These are general approximations. Actual figures vary by casino, rule set, and game variant.
Return to Player (RTP) — The Other Side of the Coin
You'll often see RTP (Return to Player) mentioned alongside slots and video poker. RTP is simply the inverse of the house edge:
RTP = 100% − House Edge
A slot with a 96% RTP theoretically returns $96 for every $100 wagered over its lifetime. The remaining 4% is the house edge. Higher RTP = lower house edge = better odds for the player.
Does the House Edge Guarantee You'll Lose?
No — not in any single session. The house edge is a long-run average. In short sessions, variance (luck) plays a large role. You can walk away ahead, even on games with a significant house edge. However, the longer you play, the more your results will trend toward the mathematical expectation.
This is why setting a session budget and win/loss limits is so important — locking in a win before variance swings against you is a smart practice.
How to Use House Edge Knowledge Practically
- Choose lower-edge games: If entertainment value is equal, prefer games with a lower house edge.
- Learn optimal strategy: Games like blackjack and video poker reward skill — bad decisions increase the effective house edge you face.
- Avoid high-edge side bets: Many table games offer side bets with house edges of 10% or more. They add excitement but eat into your bankroll quickly.
- Understand variance: A high-variance game (slots) can swing wildly; low-variance games (baccarat) produce steadier results. Choose based on your goals and budget.
Key Takeaway
The house edge isn't a secret conspiracy — it's a transparent mathematical feature of every casino game. Understanding it lets you approach gaming with clear expectations, make smarter game choices, and avoid bets that drain your bankroll unnecessarily. Knowledge of the house edge is the foundation of informed, responsible play.