Every casino game is designed to make money for the casino over time. That's not a secret or a scam—it's simply how the business works. Understanding the "house edge" helps you make smarter choices about where to play and set realistic expectations for your gambling sessions.
What Is the House Edge?
The house edge is the casino's built-in advantage, expressed as a percentage. It represents how much of your wagers the casino expects to keep over millions of plays.
Simple example: If a game has a 5% house edge, the casino expects to keep $5 for every $100 wagered over time. You might win or lose on any individual session, but across all players and all bets, the math works in the casino's favor.
Think of the house edge as the cost of entertainment. Just like movie tickets or concert admission, gambling has a price—and the house edge is how you calculate it.
House Edge vs. RTP
These two concepts are opposite sides of the same coin:
- House Edge: What the casino keeps
- RTP (Return to Player): What players get back
If a slot machine has a 95% RTP, it has a 5% house edge (100% - 95% = 5%).
Both describe the same thing from different perspectives:
- Casinos talk about house edge
- Slot machine manufacturers advertise RTP
Why the House Always Wins (Long Term)
The house edge means that statistically, casinos make money over time. But this doesn't mean you'll always lose:
- Short term: Anything can happen. You might win big or lose everything in one session.
- Long term: The math catches up. Play long enough and the house edge takes its toll.
This is why setting session limits and win goals matters—you want to leave during a winning streak, not play until the math inevitably catches up.
House Edge by Game
Table Games
| Game | Bet Type | House Edge |
|---|---|---|
| Blackjack | Basic strategy | 0.5% |
| Blackjack | Average player | 2-3% |
| Craps | Pass/Don't Pass | 1.4% |
| Craps | Taking odds | 0% |
| Craps | Proposition bets | 10-17% |
| Baccarat | Banker bet | 1.06% |
| Baccarat | Player bet | 1.24% |
| Baccarat | Tie bet | 14.4% |
| Roulette (European) | Any bet | 2.7% |
| Roulette (American) | Any bet | 5.26% |
| Roulette (American) | Five-number bet | 7.89% |
| Pai Gow Poker | Optimal strategy | 2.5% |
Slot Machines
Slot house edges vary widely:
| Slot Type | Typical House Edge |
|---|---|
| High-limit dollar slots | 2-5% |
| Standard slots | 5-10% |
| Penny slots | 8-15% |
| Progressive jackpots | 8-15% |
Casinos don't post slot machine house edges. You can estimate based on denomination—higher denomination machines typically have lower house edges.
Video Poker
| Game | Pay Table | House Edge |
|---|---|---|
| Jacks or Better | 9/6 (full pay) | 0.46% |
| Jacks or Better | 8/5 | 2.7% |
| Deuces Wild | Full pay | -0.76% (player edge) |
| Double Bonus | 10/7 | 0.17% |
Video poker offers some of the best odds in the casino—if you find full-pay machines and use optimal strategy.
Sports Betting
Standard sports bets have about a 4.5% house edge (the "vig" or "juice"):
- Bet $110 to win $100
- The $10 difference is the casino's profit margin
Breaking Down the Best and Worst Bets
Best Bets in the Casino
1. Blackjack with Basic Strategy (0.5%) Memorize or bring a basic strategy card. Every decision has a mathematically optimal play.
2. Craps Odds Bet (0%) After a point is established, you can place an "odds" bet with zero house edge. It's the only bet in the casino with no advantage for the house.
3. Baccarat Banker Bet (1.06%) Simple game, low edge. Just bet Banker every hand.
4. Video Poker Full Pay (0.5% or less) Find 9/6 Jacks or Better machines and play perfect strategy.
Worst Bets in the Casino
1. Slot Machine Bonus Bets/Side Games Often have edges of 10%+.
2. Keno (25-40%) The worst odds in most casinos. Fun for small amounts, terrible for serious gambling.
3. Big Six Wheel (11-24%) The spinning wheel of prizes looks enticing but has brutal odds.
4. Craps Proposition Bets (10-17%) The bets in the center of the table ("hard ways," "any seven") have terrible odds.
5. Baccarat Tie Bet (14.4%) Attractive 8:1 payout masks horrible odds.
6. Roulette Five-Number Bet (7.89%) Betting 0, 00, 1, 2, 3 on American roulette has the worst odds on the table.
Understanding What the Numbers Mean
$100/Hour Example
Let's say you're betting $20 per hand at blackjack, playing 50 hands per hour:
With basic strategy (0.5% edge):
- Total wagered: $20 × 50 = $1,000/hour
- Expected loss: $1,000 × 0.5% = $5/hour
Without strategy (2.5% edge):
- Total wagered: $1,000/hour
- Expected loss: $1,000 × 2.5% = $25/hour
The same game costs 5× more when you don't know basic strategy.
Why Low Edge Games Matter
Over a weekend gambling session (say, 10 hours):
| Game | House Edge | Expected Loss |
|---|---|---|
| Blackjack (basic strategy) | 0.5% | $50 |
| Roulette (American) | 5.26% | $526 |
| Penny slots | 12% | $1,200 |
Assumes $1,000/hour in wagers
The game you choose dramatically affects your expected cost of entertainment.
Variance: Why Short-Term Results Vary
House edge is a long-term statistical concept. In the short term, variance creates wild swings:
High variance games:
- Big wins and losses
- Can win big quickly or lose everything fast
- Slots, craps side bets, roulette single numbers
Low variance games:
- Smaller, more frequent wins/losses
- Bankroll lasts longer
- Blackjack, baccarat, pass line craps
A 0.5% house edge doesn't mean you'll only lose 0.5% tonight. You might win 50% or lose 100% of your bankroll. The 0.5% is the average across millions of hands.
How Casinos Create House Edge
Different games build in their edge differently:
Payout Adjustments
In roulette, there are 38 numbers (including 0 and 00), but winning numbers pay 35:1, not 37:1. The difference is the house edge.
Commission
Baccarat takes a 5% commission on winning Banker bets. This creates the house edge on an otherwise fair game.
Rule Restrictions
Blackjack rules like "dealer hits soft 17" or "blackjack pays 6:5" increase the house edge compared to player-favorable rules.
Progressive Contribution
Part of each slot machine bet feeds the progressive jackpot rather than potential payouts, reducing overall RTP.
Strategies Based on House Edge
If You Want to Gamble Longer
Choose low house edge games:
- Blackjack with basic strategy
- Craps pass line with odds
- Baccarat banker bets
Your bankroll lasts longer when less of each bet goes to the house.
If You Want Big Win Potential
Accept higher house edges for bigger upside:
- Progressive slot machines
- Roulette single numbers
- Craps proposition bets
Higher variance means bigger potential wins (and losses).
If You're Counting Entertainment Value
Some games are more fun despite worse odds:
- Slot machines (engaging, themed, relaxing)
- Craps (exciting, social atmosphere)
- Big Six wheel (simple, dramatic)
There's nothing wrong with playing for entertainment, just understand the cost.
Common Misconceptions
"I'm Due for a Win"
False. Each spin, hand, or roll is independent. Previous losses don't make wins more likely.
"Betting Systems Beat the House Edge"
False. Martingale, Fibonacci, and other betting systems don't change the underlying math. They change how you experience wins and losses but can't overcome the house edge.
"Hot and Cold Machines/Tables"
False. Short-term streaks are normal variance, not predictive patterns. A slot that hasn't paid doesn't owe you.
"The Casino Is Cheating"
Extremely unlikely at licensed casinos. Gaming commissions audit equipment and procedures. The house edge is all they need—cheating would risk their license for minimal gain.
The Bottom Line
The house edge is real, unavoidable, and nothing personal. Every casino game is designed so the casino profits over time. This doesn't mean you can't win—it means you should:
- Choose games wisely: Lower house edge means your money lasts longer
- Learn strategy: Games like blackjack punish uninformed play
- Set limits: The longer you play, the more the math catches up
- Treat gambling as entertainment: The house edge is the price of admission
Understanding odds won't guarantee wins, but it helps you make informed choices about where, how, and how long to gamble.