Core Topics
House Edge and Odds in Casino Games
The measure used throughout this site: house edge, return, volatility, and expected cost per hour.
The house edge is the single measure that allows every casino game to be compared. It states the share of each bet that, as a long-run average, does not come back to the player. A house edge of 2.70% means an expected cost of 2.70 units for every 100 units staked, whatever happens on any one round.
This page explains how that figure is calculated, how it relates to return to player and to volatility, and how to turn it into an expected cost per hour. Every figure in the game guides on this site uses the definitions set out here.
House Edge and Return Defined
The house edge comes from the gap between the payout offered by the table and the true odds of a result. The clearest example is a single-number bet on a European roulette wheel.
- A European wheel has 37 pockets, so the chance of any one number is 1 in 37.
- A fair payout for those odds would be 36:1, that is 36 times the stake plus the stake itself.
- The table pays 35:1, leaving a gap of one unit out of 37 possibilities.
- One divided by thirty-seven gives 0.0270, or 2.70%. That is the house edge of European roulette.
Return to player is the complement of the house edge: a 97.30% return is the same thing as a 2.70% house edge. The term return is used more often for machine games and house edge for table games, but both measure the same quantity.
House Edge of the Ten Games
The table below lists the house edge of each game on the bet that favours the player most. Other bets within the same game are almost always more expensive.
| Game | Type | House edge | Lowest-edge bet |
|---|---|---|---|
| Baccarat | Card Games | 1.06% | Banker |
| Blackjack | Card Games | 0.46% | Main bet played with basic strategy |
| Roulette | Wheel and Dice Games | 1.35% | Even-money bet on a French wheel with la partage |
| Sic Bo | Wheel and Dice Games | 2.78% | Big or Small |
| Dragon Tiger | Card Games | 3.73% | Dragon or Tiger |
| Texas Hold'em | Card Games | 2.19% | Ante in the Ultimate Texas Hold'em variant |
| Slot Machines | Machine and Number Games | 2% to 8% | A machine with a published return of 96% or above |
| Video Poker | Machine and Number Games | 0.46% | Jacks or Better 9/6 played at five credits |
| Craps | Wheel and Dice Games | 1.36% | Don't pass, backed by free odds |
| Keno | Machine and Number Games | 25% to 29% | Machine keno with the highest available return |
The gap between the smallest and largest figure in that table is more than fiftyfold. The choice of game and bet therefore matters far more than any betting system ever devised.
Edge per Bet and Edge per Amount Wagered
In games that call for additional wagers, such as craps with odds or Ultimate Texas Hold'em with its play bet, the house edge can be stated in two ways.
| Measure | Divided by | Use |
|---|---|---|
| Edge per initial bet | The first wager | Comparing games with one fixed stake |
| Edge per amount wagered | The average of all wagers in a round | Comparing games that call for additional wagers |
Ultimate Texas Hold'em carries a house edge of 2.19% of the ante but only about 0.53% of all money wagered, because the average total stake reaches 4.15 times the ante. Both figures are correct; what differs is the denominator.
Turning House Edge Into Cost per Hour
The most useful figure for a player is not the house edge but the expected cost of an hour of play. It is the product of three numbers: rounds per hour, stake per round, and house edge.
| Game | Rounds per hour | House edge | Expected cost per hour |
|---|---|---|---|
| Baccarat, Banker bet | 60 | 1.06% | 31.80 |
| Blackjack with basic strategy | 70 | 0.46% | 16.10 |
| European roulette | 40 | 2.70% | 54.00 |
| Sic bo, Big or Small | 100 | 2.78% | 139.00 |
| Dragon tiger | 120 | 3.73% | 223.80 |
| Slot machines at 96% return | 600 | 4.00% | 1,200.00 |
The table shows something that is often missed: a game with a small edge but very fast rounds can cost more than a game with a large edge and slow rounds. The slot machine in the example above carries an expected cost thirty-seven times that of blackjack at the same stake.
Volatility: The Measure That Completes the Picture
Two bets with the same house edge can feel entirely different. The difference is volatility, meaning how far actual results stray from the average.
| Bet | House edge | Chance of winning | Payout | Spread of results |
|---|---|---|---|---|
| Red or black | 2.70% | 48.65% | 1:1 | Shallow swings, long sessions |
| Single number | 2.70% | 2.70% | 35:1 | Deep swings, short sessions |
Players who value time at the table choose low-volatility bets, while players who value the chance of a large payout choose high volatility. Both carry the same long-run cost.
Common Errors in Reading the Odds
- Treating the house edge as a per-session figure. It is a long-run average; one session can land far from it.
- Believing past results affect the odds. Dice, wheels and machines keep no record. The belief is covered on the beginner mistakes page.
- Mistaking a big payout for good odds. A 150:1 payout in sic bo leaves a 30.09% house edge, while the 1:1 Big bet leaves 2.78%.
- Ignoring the number of rounds. Exposure is set by total money cycled, not by the size of one bet.
- Believing a betting system changes the odds. Progressive systems govern stake size and move risk around; they do not remove the house edge.
Frequently Asked Questions
What is the house edge?
The house edge is the share of each bet that does not come back to the player as a long-run average. It arises from the gap between the payout offered by the table and the true odds of the result.
How is the house edge of a bet calculated?
Multiply the chance of winning by the payout, subtract the chance of losing, then reverse the sign. For a single number on European roulette: 1/37 times 35 minus 36/37 gives minus 0.0270, a house edge of 2.70%.
How does the house edge relate to return to player?
They are complements that add to one hundred percent. A 96% return is a 4% house edge, and a 1.06% house edge is a 98.94% return.
Which game has the lowest house edge?
The odds bet in craps carries none at all, though it can only be placed alongside a main bet. Beyond that, blackjack with basic strategy at about 0.46% and full-pay video poker at 0.46% are the lowest.
Why does cost per hour matter more than house edge?
Because cost per hour accounts for the speed of the game. A machine with a 4% edge running six hundred spins an hour costs far more than a table with a 2.70% edge running forty rounds an hour.
Can a player reduce the house edge?
In some games, yes. Choosing the lowest-edge bet, following basic strategy at blackjack, selecting a full-pay video poker machine, and backing a craps bet with odds all reduce the edge carried.