House edge explained

House edge explained: the casino's built-in margin

The house edge is the casino's average profit on a bet, written as a percentage of the amount bet. It's built into the rules and payouts of every game, which is how casinos stay in business without needing to know who wins any single hand or spin. Our short house edge definition has the one-paragraph version.

Its mirror image is RTP, or return to player: the share of wagered money a game pays back over the long run. They always add up to 100%. A slot reported at 96% RTP has a 4% house edge; a blackjack game at 99.5% has a 0.5% edge.

The word "average" matters. The edge says nothing reliable about one session. You can win or lose far more than the edge suggests in an evening. What it does tell you is the price of playing, and over enough bets, results move toward it. That's why gambling is best treated as paid entertainment, with losses as the expected outcome.

Where the house edge comes from in each game

Casinos create the edge in a handful of ways. Knowing which one a game uses tells you where to look in its rules.

You'll find each in practice in our guides to sic bo, pai gow poker, three card poker and casino hold'em, and for slots in how slot RTP works.

How to calculate the house edge yourself

For any game where you can count outcomes, the method is the same. Here it is with a $1 straight-up bet on single-zero roulette, which has 37 pockets and pays 35 to 1.

1. List every outcome and how often it happens: 1 winning pocket, 36 losing pockets, 37 in total.
2. Write what each outcome pays per $1: win $35, or lose $1.
3. Multiply and add: (1 × $35) + (36 × −$1) = −$1 over 37 spins.
4. Divide by the number of outcomes: −$1 ÷ 37 = −2.70% per bet. That's the house edge.
5. Check it against the published RTP: 100% − 2.70% = 97.3%, which matches the 97.3% third-party sources report for RTG's European Roulette.

Do the same on a double-zero wheel with 38 pockets and you get −$2 ÷ 38 = 5.26%, almost twice the cost for the same payout. For slots, you can't count outcomes yourself, so you rely on the published RTP; our casino math basics guide covers both approaches.

House edge of RTG games: reported RTP figures

RealTime Gaming doesn't publish RTPs in a source we could check, so the figures below come from third-party databases and reviews such as GamesHub's RTG listings (opens in a new tab) and PokerListings' RTG overview (opens in a new tab). Treat them as guides, and look for the figure in each game's help screen.

Two caveats. Video poker and blackjack figures assume near-perfect strategy; casual play returns less. And no RTP was found at all for several RTG table games, including Pai Gow Poker, Sic Bo, Caribbean Hold'em and Craps. Our list of high RTP casinos goes further.

What the house edge costs you in dollars

The edge applies to the total you bet, not the cash you deposit. Suppose you bring $50 and play 300 spins at $1. You've wagered $300, even if your balance never went above $70, because wins get bet again. That total is called turnover, and it's what the edge works on.

The same $50 buys very different amounts of play depending on the game. Speed matters too: a game you play twice as fast puts twice the turnover through the same edge in an hour. The budgeting steps further down turn this into a simple planning tool.

House edge vs volatility: why sessions feel random

The edge sets the average; volatility sets how far results scatter around it. A low-volatility game gives frequent small wins and a steady drift down. A high-volatility game can go long stretches without a hit and then pay a large win, so short sessions vary enormously.

Two games with the same 4% edge can feel nothing alike. That's why a lucky night doesn't mean a game is "loose", and a bad one doesn't mean it's rigged. For more, read slot volatility explained and our answer to are slots rigged online.

Can strategy lower the house edge?

Only in games where you make choices that affect the outcome, and only down to the game's minimum. Nothing lets you play with an edge in your favor in RNG casino games.

Betting systems such as the Martingale change the size of your bets, not the edge on each one. Card counting is history and theory only online, because RNG blackjack reshuffles every hand. For the skill games, see blackjack basic strategy and video poker strategy.

House edge and bonuses: the wagering math

Bonuses look like extra money, but wagering requirements push a large turnover through the edge before you can withdraw. Here are three worked examples using published terms and a slot with a reported 96.25% RTP (3.75% edge). They're illustrations, not the offers via our links, whose terms are shown at sign-up.

In all three, the expected cost of the wagering is larger than the bonus itself. That doesn't mean nobody ever cashes out, because variance means some players finish ahead. It does mean a bonus is extra playing time with conditions, not extra value you can count on. The SlotoCash figures come from its bonus terms (opens in a new tab); the Slot Madness terms are reported by LCB's Slot Madness listing (opens in a new tab).

For the full method, including max bet limits and max cashout caps, read our guides to the expected value of a bonus and wagering requirements explained.

House edge myths US players still believe

• "A 96% RTP means I'll get $96 back from $100." Only as a long-run average across huge numbers of bets. One session can end anywhere.
• "This slot is due to pay." RNG results are independent. A long dry spell doesn't make a win more likely next spin.
• "Small bets avoid the edge." The edge applies to every bet. Smaller bets lose less per spin, but more spins add it back.
• "Doubling up recovers losses." Progressions raise your stakes, and the edge applies to each larger bet.
• "Offshore RTPs are checked by US regulators." They aren't. Offshore casinos aren't licensed by any US state; any testing is private.

House edge at offshore vs state-licensed casinos

In the seven states that license online casinos (New Jersey, Pennsylvania, Michigan, West Virginia, Delaware, Connecticut and Rhode Island), games run under a state regulator, which gives players a formal route for complaints. Our player protections comparison explains the difference.

Offshore casinos, including our partners, aren't licensed by any US state. Third-party reviewers report that RTG games are tested by Technical Systems Testing, but there's no US state oversight of payouts or game settings. Regulators have acted against these sites: Michigan's Gaming Control Board named SlotoCash in its October 8, 2026 cease-and-desist release (opens in a new tab), and Slot Madness in an August 14, 2025 order, as illegal offshore operators. Check your state's law before playing; our offshore casinos legality page summarizes it.

Using the house edge to set a gambling budget

1. Pick the amount you're happy to spend on entertainment this month, and treat it as spent.
2. Choose your game and find its RTP in the help screen; work out the edge (100% − RTP).
3. Estimate turnover: bet size × bets per session. Multiply by the edge to see the expected cost.
4. Adjust stake or session length so the expected cost fits your budget, with room for bad luck.
5. Set deposit limits or ask support to apply them, and stop when the budget's gone.
6. If you're chasing losses or hiding play, contact the National Problem Gambling Helpline at 1-800-MY-RESET (1-800-697-3738) by call, text or chat via NCPG (opens in a new tab), or visit our responsible gambling hub.

Low house edge games at casinos with an offer via our links

Every partner below runs RealTime Gaming or SpinLogic games, so the RTP table above applies to the titles they carry; check each casino's lobby for specific games. These are offshore casinos, not licensed by any US state, so check your state's law first. You must be 21+ (18+ where allowed) and terms apply. We earn a commission through these links, and the order is commercial.

• Slot Madness Casino: $2,500 Welcome Bonus + 50 Free Spins, via our link (new players, 21+ or 18+ where allowed, terms apply). Third-party reviews report a $30 minimum deposit, 30x (bonus + deposit) wagering on slots and no max cashout.
• SlotoCash Casino: $6,000 Welcome Bonus + 60 Free Spins, via our link (new players, 21+ or 18+ where allowed, terms apply). Its own terms list 25x (deposit + bonus), a $20 minimum per bonus and no max cashout (primary); table games, video poker and specialty games are excluded by default, and its site advertises a different package.
• Decode Casino: $5,000 Welcome Bonus + 50 Free Spins, via our link (new players, 21+ or 18+ where allowed, terms apply). Decode's own site shows no bonus terms; third-party reviews report codes with 25x to 50x wagering and $25 to $50 minimums, and report that it refuses players from Maryland, New Jersey, New York and Washington.

Bonuses at all three are built for slots, and low-edge games such as video poker and blackjack are often excluded or carry heavier wagering. Read our Slot Madness review, SlotoCash review and Decode review, or go back to our casino guides.

21+ (18+ where allowed). Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: responsible gambling tools and free help. Gambling problem? Call or text 1-800-MY-RESET (1-800-697-3738).