The house always wins. It’s such a common phrase that most casino players understand the house has an advantage, but few realise how much it varies between games. For example, the house has an edge of just 0.5% when playing blackjack optimally at casino sites, but the house edge is 5.26% when playing American roulette.
We have taken a closer look at what the house edge is, how it is calculated, and which casino game gives you the best odds of beating the house.
What is house edge?
The term house edge refers to the percentage of every wager that the casino expects to keep over the long run. For example, if a game has a house edge of 2%, the casino expects to keep £2 of every £100 wagered across millions of plays. That percentage figure is the advantage a casino has over the long-term, not a prediction of an individual session. Essentially, the house edge is the mathematical advantage built into the rules, and it is the reason casinos remain profitable.
How is the house edge calculated?
Knowing the house edge figure is one thing, but understanding how it can affect your chances of winning is another entirely. To delve deeper into this topic, we are going to pretend we are playing European roulette. The wheel has 37 pockets: 18 red, 18 black, and one green zero. Betting on either red or black pays out even money, meaning you’ll make £1 profit for every pound you wager, plus your stake back.
A red bet wins if the ball lands in any of the 18 red pockets, and loses on any of the other 19 - the 18 black pockets plus the green zero. This green zero is what provides the casino with a house edge. Without it, bettors would have a 50/50 chance of betting on the correct outcome.
Imagine staking £1 on red on every spin for 37 spins. On average, you would expect to win 18 of those spins and lose 19. Each win pays £1 in profit; each loss costs £1. Across 37 spins, you would win £18 and lose £19, giving bettors a net loss of £1. That £1 lost out of £37 staked is the house edge, which is one divided by 37, working out to 2.70%.
That means for every £100 staked on red over a long enough run, the casino keeps an average of £2.70. In theory, the player keeps the other £97.30, but it doesn’t work like that with returns fluctuating due to the unpredictable nature of gambling.
Which casino game gives you the best odds?
Playing at the highest payout casinos might improve your chances of winning, but it still depends on which game you opt for. Below is a breakdown of the house edge for the most popular casino games.
- Blackjack - around 0.5% (with basic strategy)
- Baccarat (banker bet) - 1.06%
- French roulette (even-money bets, La Partage rule) - 1.35%
- Craps (pass line) - 1.41%
- European roulette - 2.70%
- American roulette - 5.26%
- Online slots - typically between 4 to 10% (varies by game)
When played with basic strategy, blackjack has the smallest house edge of around 0.5% and is the standout by some distance. You can learn the basic strategy by following a chart that tells you when to hit, stand, double or split. Because most players do not follow this strategy, established and new casinos still profit handsomely from blackjack.
Betting on the banker’s hand in Baccarat and craps pass-line are the next-best plays. These are both simple games with no skill involved, with the house edge well under two per cent.
Beware of the trap of American roulette. You get exactly the same payout for your colour landing as you would in European roulette, but the added zero in American roulette doubles the house edge for no upside. Where possible, opt for European or French roulette and avoid American roulette tables.
House edge vs RTP
Return to player, or RTP, is the same figure as house edge, but expressed from the player's side. A game with an RTP of 96 per cent has a four per cent house edge. The two always add to 100. The terms are used interchangeably at most UK casino apps or websites. Readers are likely to see RTP more commonly referred to, especially when online slots and casino games are being discussed.
What about slots?
Slots are by far the most popular casino games, but they typically carry a much higher house edge than table games. UK online slots typically run a house edge between 4 and 10%. No strategy for slots can alter the underlying odds, as each spin is decided by a random number generator (RNG). As such, to boost your chances, make sure to pick games with higher published RTP and accept session-level unpredictability.
Frequently asked questions
What is a casino house edge? A casino's house edge is the percentage of every wager that a casino expects to keep on a given game over time. A two per cent house edge means the casino should keep £2 of every £100 wagered, on average, across millions of plays. It is important to remember this is a long-term average, not a session prediction.
What is the house edge in blackjack? The blackjack house edge is around 0.5% per cent when a player follows basic strategy. The exact figure depends on rules such as the number of decks and whether the dealer hits or stands on soft 17. Without basic strategy, the edge rises sharply.
Which casino game has the best odds? Blackjack played with basic strategy offers the lowest house edge, at around 0.5%. Baccarat banker bets (1.06%) and craps pass-line bets (1.4%) are the next best, and require no strategic skill to play correctly.
Are online casinos rigged? No. Online casinos licensed by the UK Gambling Commission must use independently tested random number generators. The casino's advantage is mathematical, built into the rules of the game, rather than achieved through manipulation.
We aim to offer every online gambler and reader of The Standard a safe and fair platform through unbiased reviews and offers from the UK's best online gambling companies.
Gambling can be addictive, always play responsibly and only bet what you can afford to lose. Gambling sites have a number of tools to assist you to stay in control, including deposit limits and time outs. If you think you have a problem, advice and support is available for you now from BeGambleAware or Gamcare. Any offers or odds listed in this article are correct at the time of publication but are subject to change. Terms & Conditions apply to all offers.
