It should be no surprise that the casino has a built-in advantage on its games.  The casinos don’t beat the players because they get lucky, they beat the players because the odds are stacked in their favor.  This built-in advantage is called the house edge.  In numbers, it’s the the casino’s average profit from a player’s bet.  For example, in roulette house edge is about 5%. That means for every dollar bet, the casino keeps 5¢ as profit, and returns the other 95¢ to the players as winnings, on average.


Of course if you bet a single dollar just once then you’re not going to get exactly 95¢ back — you’re either going to lose the whole dollar or win more whole dollars.  But that’s beside the point.  The point of the house edge is to see what the average loss is.  If all the roulette players in a casino collectively gamble $1 million on a Friday, night, the casino expects to pay back around $950,000 as winnings and keep around $50,000 as profit.


The longer you play, the closer your losses will domino qq approach the house edge. That’s another way of saying that the casino always wins in the long run. The twist is that the house edge tells us how much the casino will win on average. Here’s a program that plays roulette to show what happens the longer you play.  Note that the actual house edge in American roulette is 5.26%.


House Edge Simulator

Bet $5 on red…

Total Amount Bet

Amount Won

or Lost

Percentage Loss

1 time


10 times


100 times


1000 times


100,000 times


1,000,000 times


What you probably saw from the test above is that between 1 and 100 times, anything could happen.  You might be ahead after 100 rounds.  But the more rounds you play, the more likely you are to lose.  And after 100,000 rounds your loss will be pretty close to the 5.26% house edge.


The casino doesn’t have to beat every player every time.  They just know that they’ll win around 5.26% of the total of all roulette bets placed over the year.


So that’s how the house edge works.  The casino doesn’t have to destroy you with terrible odds — they give you an almost even game and make just a few percent on each bet on average.  And that’s why they don’t have to cheat: they have a built-in mathematical advantage on every game, so cheating is pointless.  All the have to do is get you to play, and they’ll win in the long run.


The grind

So if the casino takes only a 5.26% profit on roulette, why do most players lose 100%?  It’s because the house edge applies to the amount you bet, not the amount you take to the casino.  Let’s say you sit down at a roulette table with $100, and bet $5 a spin. You’re betting about $150/hr., even though you brought only $100 with you.  That’s because you win some rounds as you play, and you’re betting from your winnings.  After 13 hours of play (if you last that long), you’ve bet $1950.  And 5% of $1950 is $97.50, almost your full $100.

The effect of the house edge whittling away at your stash as you constantly rebet it is called the grind.  To lessen the effect of the grind, play games with a lower house edge, and play for shorter periods of time.


House edge of popular casino games

The house edge is different from game to game. Here’s the house edge for the most popular casino games.


House Edge of Casino Games (and the Lottery)


House Edge (with proper play)

Maximum Payoff per unit bet




1.5 to 1

Craps, 1x Odds



2 to 1

Video Poker



800 to 1




1 to 1




35 to 1

Slot Machines, flat top



5,000 to 1

Slot Machines, progressive



millions to 1




thousands to 1

State Lottery, typical



millions to 1

The catch here is that if you don’t play the proper strategy, the house edge is even higher.   A typical blackjack player probably plays at about a 2% disadvantage, not the 0.5% listed in the table which is for a player using basic strategy.  A craps player who makes sucker bets is facing a house edge higher than 0.8%.  A video poker player who is just guessing rather than using a strategy card is likewise getting worse odds.  This doesn’t apply to games that have no strategy, like roulette and slot machines, where you generally get the same odds no matter how you play.  For more on strategy, see our Crash Course in Table Games.

Notice that the harder a game is to master, the better the odds.  It takes some time to learn how to play blackjack, craps, or video poker properly, but they have the lowest house edge.  The simplest games, like slot machines, keno, and the lottery, have the highest house edge.  But notice the simplest games have the biggest jackpots.  That’s why people flock to them.


Why is a low house edge important?

You might wonder, “If you’re just hoping to win in the short term, then why bother looking for the games with the lowest house edge?” The answer is that:


(1) The smaller the house edge, the more likely you are to win.

(2) The house edge constantly grinds away at your money, and the higher the edge, faster your money will run out. Running out of money while you still want to play isn’t fun.


(3) The longer your money lasts, the longer you’ll play, and the more opportunity you have to win.


The ways to fight the house edge are important so let’s repeat them:


Play the games with the lowest house edge.  These include blackjack, craps, and baccarat.


Learn the best strategy for those games.  Blackjack has a small potential house edge (0.5%), but you only get the edge to be that small if you know how to play Blackjack properly.  If you’re just winging it, the house edge will be higher.  See our crash course in table games to start learning good strategy.


Make a small number of bets.  The more bets you make, the more you expose yourself to the house edge.  Slots are the worst because they’re played so quickly — lots of bets in a short amount of time.  The ultimate way to make fewer bets (besides not playing at all) is to use my half-bankroll system.


Take advantage of comps.  The casino will give you free meals, show tickets, and discounted rooms based on how much you play.  You might as well take advantage of these freebies.  See our page about comps for more.


Quit while you’re ahead.  The odds are against you.  The longer you play, the more likely you are to lose.  Quitting while you’re ahead is the only way to guarantee that you walk away a winner.


Why play when there’s a house edge?

You might wonder, “Why play at all if the house has the advantage?”  That’s a good question. You’re likely to lose when you gamble, which is indeed an excellent argument for not gambling.

But of course, even if the odds are against you, it’s possible to win.  That would have to be the case, otherwise nobody would play. Anything can happen in the short term.  The odds are against your getting heads twice in a row from two coin flips, but it could happen.  If you played baccarat for a year, you’d expect to be seriously in the red at the end of that year.  But what about for just a weekend trip to Vegas?  You could certainly come out ahead.  The odds are against it, but it’s definitely possible.


Another reason is that if you know what you’re doing, it’s cheap entertainment. A blackjack player using proper strategy at a $5 table expects to lose only $1.50/hr.  If she tips $5/hr. that’s a total loss of $6.50/hr.  That’s cheaper than most forms of entertainment, like movies, and it’s certainly cheaper than Vegas shows.


Jackpots vs. the House Edge

My main gambling advice is to avoid slot machines, because they have a high house edge that sucks down your money hand over fist.  Play any table game and your money will last a lot longer.

Slot players counter that slots offer the chance of a big jackpot, while table games don’t.  With slots you can win thousands (or millions) for a measly quarter or two.  But a $10 at blackjack will win you only $10 or $15.  And a loss will wipe out your $10 — a much bigger loss than the 25¢ or $1 you lost on the slot.


Okay, I hear you.  But there are two things to consider:


You pay a hefty price for the chance of hitting the jackpot.  The high house edge on slots depletes your bankroll much more quickly, which means either less playing time (and less fun) if you bust out, or bigger losses (and less fun) even if you don’t lose everything.  Take a look at the table again (above), and notice that there’s an almost direct correlation between the house edge and the amount you can win from one bet.  The more you can win at once, the higher the house edge.

You can win the same jackpot on a table game, simply by doubling your bet several times in a row when you’re on a winning streak.  See our article on how to win a million dollars for more on this.