House Edge Explained
Understanding the mathematical advantage that makes casinos profitable.
Every casino game is designed with a built-in mathematical advantage for the house. Understanding this concept – the "house edge" – is fundamental to being a smart gambler.
What is the House Edge?
The house edge is the percentage of each bet that the casino expects to keep over the long run. It's expressed as a percentage of your total wagered amount.
In American roulette, betting on red gives you 18 winning numbers out of 38 (not 36). The two green zeros are what create the house edge.
A 5.26% house edge means that for every $100 you bet over time, you can expect to lose $5.26 on average. The remaining $94.74 goes back to you.
House Edge vs. Return to Player (RTP)
RTP is simply the inverse of house edge:
If a slot has a 4% house edge, it has a 96% RTP – meaning it returns 96 cents of every dollar wagered on average.
Good to Know
House Edge by Game
Different games have vastly different house edges. Here's a comparison:
House Edge by Game
Lower is better for the player
Strategy Insight
Short-Term vs. Long-Term
The house edge is a long-term mathematical certainty, but short-term results can vary wildly.
You might win big in a single session – that's luck (variance). But if you play the same game thousands of times, your results will converge toward the expected house edge.
Warning
Why This Matters
Understanding house edge helps you:
- Choose smarter games – Blackjack vs. Keno is not a close call
- Set realistic expectations – You're paying for entertainment, not a guaranteed outcome
- Avoid scams – If a "system" claims to beat the house edge, it's likely a scam
- Budget appropriately – Higher house edge = faster bankroll depletion
Good to Know
Use our Hold Calculator to see sportsbook margins on any market, or the Bonus Calculator to see how house edge affects bonus value.
Sources & References
- American roulette house edge (5.26%) — mathematical derivation: 2 zero slots ÷ 38 total slots = 5.263%. Single-zero (European) roulette: 1 ÷ 37 = 2.703%. Independently verifiable.
- Nevada Gaming Control Board. Nevada Gaming Abstract. Published annually at gaming.nv.gov. Referenced for reported game win percentages (hold rates) across casino game categories in Nevada.
- Independence of trials — Bernoulli trial model (standard probability theory). Past outcomes do not affect future probabilities in games with fixed odds.
- BonusBell platform analysis — RTP and hold comparisons derived from analysis of 220+ tracked platforms as of February 2026.
Mathematical claims are independently verifiable derivations. Nevada GCB figures reflect reported hold rates across licensed Nevada casinos.
Key Takeaways
- 1House edge is the percentage the casino expects to keep from each bet
- 2RTP (Return to Player) is simply 100% minus the house edge
- 3Different games have vastly different edges – choose wisely
- 4The house edge is a long-term guarantee, but short-term results vary
- 5No betting system can overcome a negative expected value