Every casino game is priced so that the operator comes out ahead over time, and the house edge is the figure that tells you by how much. Once you know it, you can compare a blackjack table with a slot, a banker bet with a tie bet, or a single-zero wheel with a double-zero one, and see which choices drain a balance slowly and which drain it fast.
Below, we break down how the casino house edge is calculated, how it connects to return to player (RTP), where the lowest figures sit across popular games, and why even a tiny edge never protects you from a bad night. We also look at volatility, bonuses and the myths that cost players money, so you can set realistic expectations before you stake a penny.
What house edge means for your bankroll
House edge is the share of each stake a casino expects to keep across a very large number of bets, shown as a percentage. If a game carries a 5% edge, the theoretical cost of playing it is £5 for every £100 you put through it.
That figure is an average, not a fee deducted from each bet. No single spin, hand or roll costs you exactly 5%: on any given round, you either win or lose your stake. The percentage only appears when thousands upon thousands of results are added together. A casino handles an enormous volume of rounds across all of its customers, which is why its income tracks the edge closely even while individual players see completely different outcomes.
It helps to think of the edge as the price of your entertainment. A game with a 1% edge is cheap to play over time; a game with a 10% edge costs ten times as much per pound staked. The mirror image of the edge is the return to player, or RTP. Whatever the casino keeps in theory, the rest goes back to players as winnings, so a 5% house edge matches a 95% RTP.
The key word is “theoretical”. The maths describes what happens over a huge sample. Across one evening, your own results can land far above or far below that line, and those swings, known as variance, are exactly what make gambling unpredictable. They are also why gambling feels exciting: nobody can forecast what the next few rounds will bring.
Why knowing the house edge helps you choose
Knowing the house edge helps you choose because it shows, in one number, how much financial advantage a game gives the casino. With that number, you can pick games whose risk suits you.
Compare two options. On a game with a 5% edge, a player who stakes £100 in total should expect, over the long run, to be down about £5. On a game with a 10% edge, the same £100 carries an expected loss of about £10. Same stake, same time at the table, twice the cost. Multiply that across months of play and the difference becomes very real.
A lower edge generally means better value for your money over time. It does not, however, promise a winning session. Volatility, which describes how often and how big a game’s wins tend to be, can produce long losing runs on a low-edge game and lucky streaks on a high-edge one. Understanding both ideas together lets you set expectations that match reality: the edge tells you the average price, and volatility tells you how bumpy the ride will be.
For players in the UK, this knowledge is easy to put into practice. Licensed operators display RTP figures in the game information, so checking the edge before you play takes seconds. If you are new to the terminology, our casino glossary explains the common terms, and the beginner’s guide covers the basics of getting started safely.
How the casino house edge is built into each game
The casino house edge comes from probability: a game pays winning bets slightly less than their true odds, and that gap becomes the operator’s margin. Each game type creates the gap in its own way.
Table games with fixed maths
Classic games such as blackjack, roulette and craps rest on calculations that have been understood for generations. A roulette wheel has a fixed set of pockets, a shoe holds a known number of cards, and a pair of dice can only produce a fixed set of combinations. Because those structures do not change when a game moves online, a digital roulette or blackjack table has the same edge as its land-based twin, provided the rules match. The same maths applies whether you play at an online casino, an online poker site or a traditional venue.
Slots and newer electronic games
Modern slots and new video poker variants are too complex to price with pen and paper. Developers instead run computer simulations covering millions of rounds to measure exactly how much a game pays back. If the result misses the target margin, the maths model is adjusted, for example by changing symbol weightings, prize values or bonus frequency, until the long-run return lands where the designer intends.
Each individual round remains random. The simulation fixes the long-term average; it has no say over whether your next spin wins. Casino games are games of chance, and short-term outcomes cannot be predicted, whatever the edge on the game.
Who checks the numbers: providers, labs and regulators
Game providers calculate the house edge in-house first, but their own figures are only a starting point. Independent testing companies such as eCOGRA and iTech Labs run separate checks to confirm the edge is what the provider claims.
These labs test both the random number generator and the maths behind a game. That extra layer of verification is what allows players to trust the published numbers. In a regulated market, licensed games go through this kind of independent testing for fairness, and the RTP, or the equivalent house edge, is normally shown in the game’s information or help screen before you place a bet. Provider documentation often lists the same detail.
Transparency is the whole point. When you can see the RTP of a slot or the edge on a table game, you can decide for yourself which games are worth your time and money, rather than guessing.
There is one catch to keep in mind. The same title can exist in more than one version. Providers sometimes release a game with several RTP settings, and different casinos may run different ones. Bonus wagering contributions can also vary between slots, table games and live casino titles. Checking the information screen at the casino you actually use is the only reliable way to confirm what you are playing.
For a closer look at oversight, our page on casino licensing explained shows how operators are authorised, and how online casinos work explains the systems that run behind the games.
House edge and RTP: two sides of one percentage
House edge and RTP always add up to 100%: RTP is the share returned to players over time, and house edge is the share the casino keeps. A game listing a 96% RTP therefore has a 4% house edge.
In money terms, players staking £100 on that game would, on the long-run average, see £96 come back while the casino holds on to £4. The table below converts several figures used throughout this page.
| House edge (%) | RTP (%) | Kept by the casino per £100 staked (£) | Returned to players per £100 staked (£) |
|---|---|---|---|
| 2 | 98 | 2 | 98 |
| 4 | 96 | 4 | 96 |
| 5 | 95 | 5 | 95 |
| 10 | 90 | 10 | 90 |
Both numbers come from the same calculation of long-term probabilities, measured across many thousands of hands, spins or rolls. Neither is a promise about one session. A slot with a 96% RTP can return nothing during an hour of play, or several times your stake, and still be working exactly as designed. For a closer look at how return figures and swings combine, see our guide to RTP and volatility.
Slots usually advertise RTP, while table games tend to be described by house edge. You can switch between the two with simple subtraction from 100. If you want to find the highest return figures on offer, our pages on best payout slots and best payout casinos are a good place to start.
Short sessions versus the long run
The house edge only becomes reliable over a very large number of bets; over a short session, luck dominates and almost any result is possible. The casino’s advantage does not grow in a neat straight line.
Day to day, an operator can lose money on a game, win heavily or break even, and the same is true for you. Over a short spell, the house can win or lose any percentage of the money in play. Only as the number of rounds climbs does the total settle near the theoretical figure. On a 5% game, that means the casino eventually keeps about 5% of everything staked, while the other 95% flows back to players.
Variance is the name for these swings around the average. It explains why one player can walk away from a 2.7% roulette table well ahead while another loses their whole budget in twenty minutes. Neither result says anything about whether the wheel is fair.
For you, the practical lesson is to judge a game by its maths rather than by your last session. A low edge means you pay less on average for your entertainment. It does not mean you will win today, and a run of good results does not mean a game has become generous.
What the 180-day slot study showed
Academic research supports this point. A paper in the International Journal of Contemporary Hospitality Management described an experiment in which a casino placed two very similar slot machines on the same floor, one set with a larger house edge and one with a smaller edge. Across the 180 days of the study, the edge the casino actually realised on the two machines was almost identical.
Given enough time, the difference in settings would have shown up in the takings. Over six months, though, short-term noise was strong enough to hide it, and the results could have favoured either the players or the casino. If an operator cannot tell two edges apart over half a year, an individual player has no chance of doing so in an evening.
That is why staying in control matters more than trying to read patterns in your own results. Set win and loss limits before you play, and stop once you reach either one. Understanding RTP and variance makes it easier to accept that outcomes will differ a great deal from one session to the next.
Knowing the house edge only gets you so far
Knowing the house edge improves your long-term value, but it cannot remove the luck that decides short-term results. Playing low-edge, high-RTP games gives you good theoretical value, nothing more.
The value you actually realise, especially across a handful of sessions, owes a great deal to chance. You might pick the best blackjack table in the building, play perfect strategy and still lose for a week. You might pick a mediocre slot and land a big bonus round on your first visit. Both outcomes fit comfortably inside the maths.
Gambling always involves real money and a real risk of loss. Every casino game has a built-in edge, which means most players end up behind over time. Choosing games with a lower edge or a higher RTP reduces the average cost, but results in the short term can still swing sharply. Only gamble what you can afford to lose, and fix deposit, loss and time limits before you begin.
Lowest house edge games compared
The lowest house edge games are blackjack with good rules and basic strategy, some video poker pay tables, the banker bet in baccarat, French roulette and the pass line in craps. Slots usually sit higher, across a much wider range.
Each game has its own structure, so its edge is different too. Comparing blackjack with roulette is like comparing two products with different price tags. The summary below gathers the typical figures and the main factors that move them.
| Game | Bet or variant | Typical house edge (%) | What changes the edge |
|---|---|---|---|
| Blackjack | Basic strategy | 0.3–2 | Number of decks, dealer action on soft 17, doubling and splitting rules, player decisions |
| Video poker | Strategy-dependent | 0.5–5 | Pay table, variant such as Jacks or Better or Deuces Wild, accuracy of strategy |
| Baccarat | Banker | 1.06 | Commission rules |
| Baccarat | Player | 1.24 | — |
| Baccarat | Tie | 14.36 | Tie payout ratio |
| Roulette | French (La Partage or En Prison) | 1.35 | Special rules on even-money bets |
| Roulette | European | 2.70 | Single zero |
| Roulette | American | 5.26 | Extra double zero |
| Craps | Pass or Don’t Pass | 1.36 | Bet type |
| Craps | Other bets | 2–16 | Bet type, table rules |
| Slots | Varies by title | 2–10 | RTP setting, provider, volatility, bonus features |
Remember that the same game can carry a different edge from one provider to another because of pay tables and rules. A blackjack table where the dealer hits soft 17, for instance, adds roughly 0.2% to the house edge compared with a table where the dealer stands. That sounds tiny, yet across hundreds of hours of play it adds up. Some craps bets also run above the 16% shown in the table.
In skill-based games, the low figures only apply if you play correctly. Blackjack reaches its best edge only with perfect basic strategy, and the craps edge falls sharply if you stick to pass-line bets and take the maximum odds once a point is set. You can explore all of these titles in our casino games hub.
Blackjack house edge and the rules that move it
The blackjack house edge ranges from roughly 0.3% to 2% when you follow basic strategy, and the table rules decide where a game falls. At 0.3%, the theoretical cost is just 30p per £100 staked.
Blackjack is one of the most popular casino games, and the low edge is only part of the reason. Players enjoy making real decisions, such as whether to hit, stand, double down or split, and those choices directly affect the result. That control cuts both ways: playing on hunches or ignoring basic strategy can push the edge well above the figures quoted for the game.
When comparing tables, three rules work in your favour:
- The dealer stands on soft 17 instead of hitting.
- You can double down on any two starting cards, whatever the dealer’s up-card.
- The game uses fewer decks, so six decks beat eight.
Each rule trims a little from the house’s advantage, and the effects stack together. The biggest factor, though, is how you play. Basic strategy is a chart of the mathematically best move for every combination of your hand and the dealer’s visible card; always splitting aces is one example. Follow it without exception and you will be close to the lowest edge the table allows.
Even 0.3% is a theoretical number based on a very long run. In a single session, your results can drift a long way from it in either direction. Our full blackjack guide covers rules, variants and strategy in more depth.
Video poker: pay tables decide the edge
Video poker can offer a very low house edge, from about 0.5% to 5% over the long run, but the exact figure depends on the variant and the pay table. Two machines with the same game name can return different amounts.
Jacks or Better, played well on a good pay table, comes in at around 0.5%. Deuces Wild sits closer to 0.75%. The gap between those two games is fairly small, but the gap between a generous and a stingy pay table on the same game can be much bigger. One casino might pay more for a full house than another, and that single line in the pay table shifts the long-run return.
The practical step is simple. Before you play, open the pay table and compare it with the same game at other sites. Choosing the most generous version raises your theoretical RTP without any extra effort or risk.
As with blackjack, the low figures assume you hold and discard the mathematically correct cards every time. Each variant has its own best strategy, and casual play costs more than the advertised edge suggests. Our video poker guide explains the main variants and how to read their pay tables.
Baccarat: why banker beats player and tie
The banker bet in baccarat carries a house edge of about 1.06%, one of the cheapest wagers in any casino. The player bet costs about 1.24%, and the tie a steep 14.36%.
Baccarat’s glamorous image owes a lot to James Bond films, but the game itself is simple and suits every budget. You choose between three bets. Backing the banker means predicting that the banker’s hand will finish closest to 9. Backing the player means predicting the same for the player’s hand. The tie bet wins only if both hands finish level. Once the bet is placed, you make no further decisions, so the bet you pick is the only thing that affects the edge.
The tie is tempting because a winner pays 8 to 1. That large payout hides a poor long-term deal: at 14.36%, the tie costs more than ten times as much as backing the banker. Players who chase it are hoping for a short-term windfall that the maths works hard against, and over the long run, which is what every house edge and RTP figure describes, the tie strongly favours the house.
Commission rules on banker wins also influence the final number, so check the table rules before you sit down. Read more about bets, variants and etiquette in our baccarat guide.
Roulette house edge: European, American and French wheels
The roulette house edge is 2.70% on a European wheel, 5.26% on an American wheel and 1.35% on French tables that use La Partage or En Prison. The number of zeros makes the difference.
A European wheel has a single green zero. An American wheel adds a double zero, which creates one more losing pocket for every bet while the payouts stay the same. That one extra pocket nearly doubles the long-run cost of playing, from 2.70% to 5.26%. If a single-zero table is available, there is no mathematical reason to choose the American version.
French roulette uses a single-zero wheel plus one of two special rules for even-money bets, such as red or black:
- La Partage: if the ball lands on zero, half of your even-money stake is returned. A £100 bet on red would cost you £50 instead of £100.
- En Prison: if the ball lands on zero, your even-money stake stays on the table for the next spin. If that spin wins, the stake is returned to you in full.
Either rule halves the edge on those bets to 1.35%, the lowest figure on any roulette table. French roulette with one of these rules therefore offers the most favourable long-run terms of all the roulette variants, as long as you stick to even-money bets. Our roulette guide covers the rules and bet types of each version in more detail.
Slot house edge and RTP ranges
Slot house edges usually range from about 2% to 10%, a much wider spread than most table games. A 2% edge equals a 98% RTP, while a 10% edge equals 90%.
Unlike blackjack or roulette, slots have no universal rulebook. The manufacturer designs the maths model, and the casino may choose between versions of the same game with different settings. As a result, an identical title can return noticeably more at one site than at another. The best slots for players are those with the smallest house advantage, because they return the highest share of stakes.
In money terms, the gap is significant. On a slot with a 10% edge, every £100 staked returns £90 to players on average over time. On a slot with a 2% edge, the same £100 returns £98. Over a long spell of play, choosing the higher-RTP version makes your budget last much longer.
The usual warning applies with extra force. Short-term slot results are dominated by luck, especially on games with large bonus rounds. A high-RTP slot can still empty your balance quickly, and a low-RTP one can land a big win. If you prefer games with large but rare payouts, see our list of high volatility slots; for titles that let you jump straight to the feature, there is a separate page on bonus buy slots.
Craps: from the 0% odds bet to the long-shot props
The craps house edge depends almost entirely on the bet you make, from 0% on the odds bet to more than 16% on some proposition bets. Choosing the right wagers matters more here than in almost any other game.
The pass and don’t pass lines each carry an edge of about 1.36%. Once a point has been set, you can back a pass-line bet with an extra odds wager. That odds bet has a house edge of 0%, so pairing a pass-line bet with the maximum odds the table allows gives you the lowest combined edge craps can offer.
At the other end of the layout sit bets such as the hard six and hard eight. These are wagers that the dice will show two 3s or two 4s before a 7 appears, and they carry an edge of 9.09%. Across the wider range of side bets, the edge runs from about 2% to beyond 16%.
The lesson is to learn the odds of every bet before you place it. A craps table looks busy and complicated, yet most of the value sits in a few simple wagers. Everything else is an expensive way to add excitement.
Volatility, variance and house edge
Volatility and variance do not change the house edge; they change how the same long-run return reaches you. A game with a 2% edge stays a 2% game whether it pays often or rarely.
Volatility describes how often a game tends to pay and how large those wins are. High-volatility games produce fewer wins, but the wins that land are usually bigger. Variance describes how consistent the payouts are: low variance means frequent small returns, while high variance means fewer, larger hits separated by dry spells. Many players use the two words almost interchangeably.
Picture two slots, each with a 2% edge. The low-volatility one gives you regular small wins that keep your balance ticking over. The high-volatility one may go a long time without anything meaningful, then deliver a large payout. Over the long run, both return 98% of stakes. Within a single session, they feel completely different.
The long-term maths stays the same whatever the volatility, but the player experience changes a great deal. People who enjoy high-action, big-swing sessions often lean towards high-volatility games, while those who want a smoother ride tend to prefer low-volatility titles. Whichever style suits you, set your budget with the swings in mind, because a high-volatility game can use up a balance quickly before any big win arrives.
How bonuses and wagering interact with house edge
A casino bonus can improve your effective return because the casino adds money in exchange for play, but the wagering requirement means you must stake a multiple of it first. The edge on the games you use decides how much value survives.
Most bonuses follow the same pattern: you deposit, the casino adds bonus funds, and you must wager a set amount before you can withdraw them. Under rules introduced by the UK Gambling Commission, a casino cannot require you to wager more than 10 times the bonus value. A £100 bonus therefore needs no more than £1,000 of qualifying stakes. Our page on wagering requirements explains how these targets are set and tracked.
If you were going to stake that much anyway, a bonus effectively lowers the edge on your play, because part of the cost is covered by the casino’s money. What you should avoid is betting more than you are comfortable with just to unlock a bonus. You can compare current offers on our bonuses hub and the deposit bonuses page.
Game weighting and restricted games
Game weighting decides how much each bet counts towards the wagering requirement. Slots commonly count at 100%, so every pound staked reduces the requirement by a pound. Blackjack may count at only 10%, meaning £100 of blackjack stakes clears just £10 of wagering.
Some games with a particularly low edge and a high RTP may not count at all. Read the weighting section of the terms before you start, so you do not spend hours on a game that barely moves the requirement.
Working out the real cost of a bonus
Turning the terms into a single number is the quickest check. Multiply the bonus by the wagering requirement to find the total stakes, then multiply that total by the house edge of the game you plan to use.
Take a £200 bonus at the 10x maximum. You would need £2,000 of eligible stakes. On a slot with a 96% RTP, which is a 4% house edge, the expected cost of clearing the bonus is about £80. That leaves an expected £120 of value, although your actual result could be much higher or lower depending on the game, its volatility and plain luck.
Even within the 10x limit, a bonus can cost more than it first appears, so read the full terms carefully before you opt in.
Myths about house edge
House edge is a fixed mathematical property, yet short-term streaks lead many players to misread it. Three myths come up again and again, and each one can prove costly.
“I’m due a win.” After a run of losses, it is tempting to believe that a win must be close. It is not. Every spin, hand or roll is an independent event, and previous results have no influence on the next one. Nobody is ever owed a win, so carrying on because you feel “due” is one of the most expensive habits a player can form.
“This slot is hot.” Slots do not warm up or cool down. Each outcome is decided by a random number generator working to the game’s fixed maths, and a machine is only ever as generous as its settings allow. A slot that has just paid out is no more and no less likely to pay again.
“The casino changes the RTP every day.” After a big win or a heavy loss, some players assume the casino has quietly adjusted the game. That does not happen. Online casinos keep a steady RTP for each game, and you can check the figure in the game information. What you experienced was variance, not a change in settings.
The thread running through all three myths is the same: the edge works itself out over the long run, while short-term results stay unpredictable.
Practical ways to reduce the impact of house edge
You cannot remove the house edge, but you can pay less of it by picking better games, playing them correctly and controlling how much you stake. These habits apply online and in land-based casinos alike.
Pick games with a higher RTP. Check the information screen or help page before you play. Licensed UK casinos make this detail easy to find and simple to understand, and comparing two versions of a game takes only a few seconds.
Learn the strategy where skill counts. In blackjack, basic strategy is essential; you can study it online or keep a strategy card beside you. Following it makes the game more enjoyable and lowers the edge. In baccarat, stick with the banker bet. In craps, focus on the pass line plus odds. In video poker, learn the correct holds for your variant.
Choose the best version of each game. Prefer French roulette to European, and European to American. Look for blackjack tables where the dealer stands on soft 17, and video poker machines with the most generous pay table.
Set a budget and a time limit. Decide in advance how much you will spend and how long you will play. When either runs out, end the session and do something else.
Treat gambling as entertainment. The house always holds the advantage over time, so gambling is not a way to make money. Think of your losses as the cost of a night’s fun. For more help picking a trustworthy site, read our guide on how to choose a casino, and browse the wider guides section for related topics.
Staying in control
Staying in control matters more than any house edge figure, because every casino game is designed so that most players lose over time. Set firm limits and keep gambling as a leisure activity.
Gambling can become addictive and cause serious problems in other areas of life. Warning signs include chasing losses, playing for longer than you planned and borrowing money to gamble. If gambling stops being fun or starts to feel out of control, get help straight away rather than waiting.
Support is available in the UK from BeGambleAware, GamCare and GamStop. Talking to one of these services is a sensible first step, whether you want advice, someone to listen or a way to block access to gambling sites. Our responsible gambling page has more guidance on setting limits and finding support.
Frequently asked questions
What does house edge mean in simple terms?
House edge is the percentage of each stake a casino expects to keep over a very large number of bets. A game with a 5% house edge returns 95% to players in the long run. It is an average built into the rules and payouts, so it tells you nothing certain about a single session, where luck plays the leading role.
How is the casino house edge worked out?
The casino house edge is worked out from probability, as the gap between the true odds of a bet and what it actually pays. Classic table games use long-established formulas, while slots and newer electronic games are measured with computer simulations of millions of rounds. Independent labs such as eCOGRA and iTech Labs then test the maths and the random number generator.
Does a lower house edge mean I will win more often?
No. A lower house edge reduces the average cost of playing over the long run, but it does not guarantee winning sessions. Short-term results depend heavily on luck and volatility, so you can lose on a 1% game and win on a 10% game in the same evening. Choose low-edge games for better long-term value, not as a winning system.
Does volatility affect the house edge?
No. Volatility changes how a game pays, not how much it returns over time. A high-volatility slot and a low-volatility slot with the same 2% edge both return 98% of stakes in the long run. The high-volatility game pays less often but in larger amounts, while the low-volatility game delivers frequent smaller wins.
Which baccarat bet has the lowest house edge?
The banker bet has the lowest house edge in baccarat, at about 1.06%, compared with roughly 1.24% for the player bet. The tie bet is far worse at 14.36%, despite its 8 to 1 payout. Because you make no decisions after placing a baccarat bet, choosing banker is the main way to keep the cost of playing low.
Can the same game have a different house edge at different casinos?
Yes. Many games come in more than one version, and rules or pay tables can differ between providers and casinos. A blackjack table where the dealer hits soft 17 adds about 0.2% to the edge, and video poker pay tables vary from site to site. Always check the game information screen at the casino you are actually using.
How does the house edge affect the cost of clearing a casino bonus?
The house edge sets the expected cost of clearing a casino bonus: total wagering multiplied by the edge of the game you use. A £200 bonus at the UK 10x maximum needs £2,000 of eligible stakes, so on a slot with a 4% edge (96% RTP) the expected cost is about £80. Low-edge games cut that cost, but check the game weighting first, and confirm the current wagering rules in the bonus terms.