What Is the House Edge? How Every Casino Game Is Built to Win
The house edge is the built-in mathematical advantage a casino holds on every bet, expressed as the share of each wager the house expects to keep on average over the long run.
The house edge is the built-in mathematical advantage a casino holds on every bet, expressed as the share of each wager the house expects to keep on average over the long run. A 5% house edge does not mean the casino wins one bet in twenty; it means that across thousands of wagers, the house retains roughly 5 ENT for every 100 staked, while the rest returns to players as winnings. This has a mirror figure called RTP, return to player: subtract the edge from 100% and you get the RTP, so a 5% edge is the same fact stated as 95% RTP. Every game on the floor, from a roulette wheel to a blackjack table, is priced this way, with payouts set slightly below the true odds of winning; that gap is where the house's advantage lives. It is disclosed in the rules and provable with arithmetic, not concealed or manipulated bet by bet. This article shows how the edge is built into specific games, why it never predicts a single session, and how to read it clearly enough to know what you are paying to play.
What exactly is the house edge, in plain terms?
The house edge is the percentage of every wager a casino expects to keep over the long run, built into the game's payout structure rather than collected as a separate fee. It is the mirror of RTP, return to player: a game with a 95% RTP carries a 5% house edge, no more, no less.
Every casino game pays winning outcomes slightly less than their true, fair odds. That gap, between what a bet 'should' pay if the game were fair and what it actually pays, is the house edge. It is not hidden; it follows directly from the posted payout table.
The edge is arithmetic, not luck.
How is the house edge actually built into a game's payouts?
The edge comes from paying winners less than the true odds warrant. European roulette has 37 pockets, so a fair payout on a single number would be 36 to 1; the wheel actually pays 35 to 1, and that one-unit gap is the entire house edge on that bet.
This underpayment is the mechanism behind nearly every casino game. Blackjack shaves its edge through dealer rules and payout ratios; baccarat through a small commission on winning banker bets; craps through the pass line's payout ratio versus the shooter's true odds. The method changes game to game, but the payout is always a little short of fair.
- 37 pockets on a European wheel: fair odds = 36 to 1
- Actual payout on a single number = 35 to 1
- That 1-unit shortfall is the 2.70% edge
What house edge should I expect across the major casino games?
Edges vary by game and even by specific bet within a game. Blackjack with basic strategy sits near 0.5%; European roulette is 2.70%; American roulette (with the extra 00 pocket) rises to 5.26%; craps' pass line is 1.41%; baccarat's banker bet is about 1.06%; slots typically run 2% to 10%.
Baccarat's player bet carries roughly 1.24%, close to the banker bet, while its tie bet is an outlier at about 14.4%, proof one game can hold very different prices. Lottery-style draws and keno sit at the high end, often 20% to 35% or more, pricing long-shot outcomes generously in the house's favor.
- Blackjack (basic strategy): 0.5%
- European roulette: 2.70%
- American roulette: 5.26%
- Craps pass line: 1.41%
- Baccarat: banker 1.06%, player 1.24%, tie 14.4%
- Slots: 2% to 10%, often 5% to 8%
- Keno / lottery draws: 20% to 35%+
Does a lower house edge always mean a cheaper night at the tables?
Not by itself. The edge only measures cost per bet; the total expected cost of a session also depends on how many bets are placed per hour and the size of each stake. A low-edge game played fast, at high stakes, can cost more overall than a higher-edge game played slowly at small stakes.
A blackjack table dealing 60 hands an hour exposes a bankroll to far more decisions than a roulette wheel spun 45 times an hour, even though blackjack's edge is lower. The rule: a lower edge, fewer bets per hour, and smaller stakes together produce a lower expected cost to play.
The edge prices a bet, not an evening.
Why do slot machines carry such a wide house-edge range, roughly 2% to 10%?
Slots bundle many small probability events, reel weightings, bonus features, and jackpot contributions, into a single payout table, so the edge depends entirely on how a particular machine is configured. Unlike a roulette wheel, the odds are not visible on the felt, so the edge can only be known from the game's published RTP.
A slot's true odds live in software, not on a wheel, so two identical-looking machines can carry different edges, commonly landing between 5% and 8%. This is why RTP disclosure matters more for slots: with roulette the edge can be derived by hand; with a slot, the stated RTP is the only source.
What is the difference between house edge and hold?
House edge is the theoretical average built into a single bet's payout. Hold is the actual share of money brought to a table or machine that the house ends up keeping, measured over a session. Hold is usually higher, because players recycle winnings back into more bets rather than walking away.
If a player buys in for 100 ENT, wins some hands, and rewagers those winnings instead of cashing out, each wager meets the house edge again. The result: the operator's hold, the share of the buy-in retained by session's end, typically runs higher than the edge on any single bet, since the same money passes through the edge repeatedly.
If the house always has an edge, why doesn't it win every session?
Because the edge is a long-run average, not a per-bet guarantee. The law of large numbers says outcomes converge toward the edge only across a very large number of bets; any single session is governed by variance, the natural swing above or below that average, which can be wide in either direction.
A player can win for an hour or a night purely from variance, even on a game with a firm house edge. Across thousands of bets and players, the average settles toward the built-in percentage, which is why the edge is reliable for a casino's business model, though it guarantees nothing about any single visit. Edge is the long-run price; variance is the short-run noise.
The house always knows this
Every game carries a small, disclosed edge in the house's favor; understanding the math is the surest way to play with clear eyes.
Frequently asked
Is a 5% house edge the same as saying a game has 95% RTP?
Yes. RTP and house edge state the same underlying number two different ways: RTP plus house edge always equals 100%. A 5% edge is exactly a 95% RTP; a 2.70% edge, as on European roulette, is the same fact stated as a 97.30% RTP.
What is the lowest house edge among common casino games?
Blackjack, played with correct basic strategy, carries roughly the lowest common edge among standard casino games, about 0.5%, or 0.5 ENT lost per 100 staked over the long run. European roulette (2.70%) and baccarat's banker bet (about 1.06%) are also comparatively low.
Why is the tie bet in baccarat priced so much higher than the banker or player bet?
A tie is a rare outcome with a large payout, and casinos price rare, high-payout bets generously in their own favor. Baccarat's tie carries about 14.4% house edge, far above the banker's 1.06% or the player's 1.24%, even at the same table.
Can basic strategy or betting systems eliminate the house edge?
No single strategy removes the edge; correct play, like blackjack basic strategy, only minimizes how much of it a player is exposed to. The edge is fixed by the game's rules and payout table, so it applies regardless of betting patterns, streaks, or systems.
Does the house edge change from bet to bet or after a losing streak?
No. The edge is fixed by the game's rules and payout structure, not by recent history. Each bet is an independent event; a wheel, a shoe, or a random number generator has no memory of prior spins or hands, so the edge stays constant.
Sources & further reading
ENTBlog is educational. Every casino game carries a house edge, so the mathematically expected result of play is a net loss over time. Play for entertainment, within limits you set in advance. Nothing here is financial advice or a promise of winnings.