Casino House Edge Explained — Every Game Compared
What the house edge means, how it's calculated, and how every major casino game compares: blackjack, roulette, baccarat, craps, poker, and slots. Includes a full comparison table.
The house edge is the single most important number in casino game mathematics. It determines the expected long-run cost of each game — and understanding it is the foundation for analysing any casino game.
What Is the House Edge?
The house edge is the casino’s mathematical advantage over the player, expressed as a percentage of each bet. A 1% house edge means the casino expects to retain 1 credit for every 100 credits wagered, on average, over many bets.
The house edge is not a per-session guarantee — you can win big or lose quickly in any single session. But over thousands of bets, the results converge toward the mathematical expectation. The longer you play, the more likely your actual results match the theoretical edge.
House edge = 1 − RTP (Return to Player)
A game with 99% RTP has a 1% house edge. A game with 94% RTP has a 6% house edge.
House Edge by Game
| Game | Best-case edge | Notes |
|---|---|---|
| Blackjack (basic strategy) | 0.5% | Varies by rules; perfect strategy required |
| Craps — pass line + max odds | 0.2–0.5% | Free odds have 0% edge; combined depends on odds taken |
| Craps — pass line (no odds) | 1.41% | Still good; add odds to improve |
| Video Poker (Jacks or Better, full pay) | 0.5% | Requires optimal hold strategy |
| Baccarat — Banker | 1.06% | After 5% commission; consistent, no strategy required |
| Baccarat — Player | 1.24% | Second best baccarat bet |
| European Roulette | 2.7% | Single-zero wheel |
| American Roulette | 5.26% | Double-zero wheel; higher edge than European |
| Slots (online) | 4–6% typical | Varies widely (2–15%); published RTP varies by title |
| Baccarat — Tie | 14.36% | High edge despite 8:1 payout |
| Craps — Any 7 | 16.67% | Highest-edge bet on the standard craps layout |
| Keno | 20–35% | Lottery-style; very high edge |
Games by House Edge
1. Blackjack with Basic Strategy — ~0.5% edge
Blackjack is uniquely skill-dependent. The house edge of 0.5% assumes perfect basic strategy — the mathematically optimal play for every hand. Without basic strategy, the edge rises to 2–4% depending on the player’s decisions.
The specific edge also varies by rules: dealer stands on soft 17 (S17), blackjack pays 3:2 (not 6:5), and the ability to double on any two cards and split up to 3 or 4 times each reduce the house edge. The free blackjack game uses standard six-deck S17, DAS rules.
2. Craps — Pass Line + Free Odds
Craps combines a reasonable flat-bet edge (1.41% on pass line) with the unique free odds bet — the only casino bet with zero house edge. Free odds pay true mathematical probabilities with no profit margin for the house.
The combined edge depends on how many times odds you take:
| Odds taken | Combined edge |
|---|---|
| 1× | 0.85% |
| 2× | 0.61% |
| 3-4-5× | 0.37% |
| 10× | 0.18% |
At 10× odds, the combined pass line + odds edge falls to 0.18% — the lowest combined edge achievable on a standard craps layout.
3. Baccarat — Banker Bet
Baccarat requires no strategy decisions. The banker bet pays 0.95:1 (after 5% commission) with a house edge of 1.06%. The tie bet carries a 14.36% edge — the disparity between the two is among the widest within a single game’s bet menu.
Edge Variation Within Games
Slots: RTP varies widely — from 85% in some land-based titles to 98% in selected online games. Published RTP is typically available in a game’s information screen. See the slots guide for context on how RTP varies across titles.
Roulette: European roulette (single zero) has a 2.70% edge; American roulette (double zero) has a 5.26% edge. The difference is the second zero pocket, which benefits neither player type but doubles the house’s share. See the roulette guide for variant rules.
Proposition bets in craps: Any 7 (16.67%), hardways (9–11%), horn bets (~12.5%) — these bets carry a substantially higher edge than the pass line or come bets on the same layout.
Why the House Edge Compounds
The house edge is applied to every bet placed, not just the starting bankroll. This means the longer you play and the more bets you make, the more the edge compounds against you.
Example: 100 credits per bet, 200 bets per hour, European roulette (2.7% edge):
- Expected return per hour: 200 × 100 credits × 0.027 = 540 credits per hour to the house
At blackjack with 0.5% edge and the same parameters:
- Expected return per hour: 200 × 100 credits × 0.005 = 100 credits per hour to the house
Game selection determines the rate of expected return to the house far more than bet sizing or betting systems.
Summary
The house edge varies dramatically across games and bet types:
- Blackjack with basic strategy and craps pass line + odds represent the lowest available edges (~0.5% or less).
- Baccarat banker (1.06%) and European roulette (2.70%) are intermediate options with no skill component.
- Slots vary from approximately 2% to 15% edge; published RTP figures are the basis for comparison.
- Within any game, the spread between the best and worst available bets can be extreme — craps pass line (1.41%) vs Any 7 (16.67%) use the same dice on the same table.
- No betting system (Martingale, Fibonacci, etc.) changes the house edge. Each rearranges when wins and losses occur, not the long-run expectation. See Betting Systems for the mathematics.