What Is House Edge?: Understanding Casino Odds

House Edge is an expression used to explain the advantage that casinos have over players.

However, it’s more than just a saying, it’s an actual mathematical sum. It refers to the statistical benefit that casinos have in each game and varies greatly depending on what type of game you play.

Experienced casino players will usually choose games that have the lowest house edge. But most casual casino players won’t necessarily know this information or where to find it.

With that in mind, let’s take a look at what house edge is, see how it differs between games and discuss how you can turn the edge in your favour.

Why Does House Edge Exist?

Having an edge over someone or something means you have some kind of upper hand or benefit. Like getting a head-start in a race or playing football with an extra player in your team.

While doing either of those things would be unfair, casinos having a House Edge is not.

The reason it’s not unfair is because casinos are a business. And just like salesmen take a commission or a selling site takes a fee, casinos have to have some kind of set-up that keeps them in business.

However, House Edge doesn’t mean that players cannot win. Casinos certainly wouldn’t last long in business if they had no winners. Not only can players win, but they can win significant amounts too.

House Edge is not about making sure the casino wins all of the time. It’s about ensuring that over a long period of time, over a significant number of players, given normal play, the casinos have a built-in percentage advantage in their games that enable them to pay out when a player hits a big win and still stay in business.

The House Edge can be minimal in some cases, but when you multiply that by thousands of games from thousands of players, it all adds up.

How Does House Edge Work?

Let’s take casino games out of it for a moment and focus on a basic ‘heads or tails’ game.

Everyone has played heads or tails at some point in their life with a coin. You throw up the coin, and call whether you think it will land with the ‘head’ or ‘tail’ facing upwards. It is a 50/50 chance because there are only two outcomes.

This means that if you were betting against the casino and you call ‘heads’, 50% of the time you would win, and 50% of the time the casino would win on average.

Now, let’s say that there’s a slight chance that the coin could land on its edge. It’s highly unlikely, and the laws of physics might have something to say about it but, in theory, let’s imagine that a third outcome is introduced, however rare it could be.

Suddenly, it’s no longer a 50/50 call as, although it's most likely that the coin lands on heads or tails, there’s also a slight chance it can land on the edge.

So now if you’re betting against the casino and you call ‘heads’, then your chance of winning drops from 50% to 48.65%. However, the casino would win whether it lands on tails or on the edge, therefore, statistically the casino’s chance of winning rises from 50% to 51.35%.

This means that the casino has a House Edge of 2.70% which is the difference between the casino’s chance of winning (51.35%) and your chance of winning (48.65%).

This, in effect, is exactly how single-zero European Roulette works. Just substitute ‘heads’, ‘tails’ and ‘edge’ in the coin toss game for ‘red’, ‘black’ and the green ‘0’ in roulette.

If you bet on one specific colour in single zero roulette, you don’t have a 50% chance of winning, you have a 48.65% chance. Meanwhile, the casino has a 51.35% chance of winning because it could land on the alternative colour or the green ‘0’.

European Roulette, therefore, comes with a House Edge of 2.70%. Which, incidentally, is the lowest House Edge you will find in roulette.

House Edge In Table Games

Whether you love a spin of the roulette wheel, a roll of the dice, or a deal of the cards, every casino game has a built-in House Edge.

The lower the House Edge, the higher the percentage chance you have of winning, as we’ve hopefully demonstrated with the coin-toss analogy above.

While many of us just play the games we enjoy, most savvy casino players will only play games with a low House Edge as they approach it mathematically. However, it does pay to know about House Edge, as it may shape your game choices in the future.

Let’s take a look at some of the most common casino games, their different variations, and how it affects the House Edge.

Roulette

As discussed, European Roulette has the lowest House Edge, due to it having a single green zero.

However, there is also double zero roulette, which is commonly known as American Roulette. Because this game expands the wheel but doesn’t increase the pay out, the House Edge rises.

If you bet on one specific colour in American Roulette you now have a 47.37% chance of winning. Meanwhile the casino has a 52.63% chance of winning because it could land on the alternative colour, the green ‘0’ or the green ‘00’.

This gives the casino a House Edge of 5.26%.

Triple zero roulette offers an even higher House Edge of 7.69% due to expanding the wheel further.

Roulette House Edge

Blackjack

There are so many different versions of blackjack, each with a varying House Edge. This is because the rules differ greatly depending on the specific version you play.

The main casino edge in blackjack, whatever version you play, comes from the fact that the player acts first. The player receives two cards and has to decide whether to hit or stand, often after only seeing one of the dealer’s cards.

This means that the player can bust out before the dealer even has to act. And even if the dealer did bust, the player would still lose.

There are many other factors that affect the House Edge of blackjack. These include:

• Whether the blackjack game offers 3:2 or 6:5 payout

• Whether the dealer must stand on 17

• Whether the player is allowed to split pairs and double down

• Whether the player sees one or both of the dealer’s cards

• How many decks are used in the blackjack game

For a player, the ideal blackjack scenario is a single deck game with a 3:2 payout, where the dealer must hit on 16, and stand on 17 and the player is allowed to split pairs and double down. In this scenario, the House Edge can be as low as 0.42% which is generally regarded as the lowest House Edge of any casino game.

This is the reason why blackjack is extremely popular with experienced casino players.

However, if you alter some of the elements above, for example, add in extra card decks, or a 6:5 payout etc then this gives the casino more advantage and therefore increases the House Edge.

Even in the least favourable conditions for a player, though, blackjack House Edge rarely rises above 2%, which makes it a good option for savvy players.

Baccarat

With Baccarat there are only three outcomes to the game and you predict it before any cards are dealt. The potential three outcomes are:

a. The Banker has the best hand

b. The Player has the best hand

c. There is a tie

Players bet on one of the three outcomes meaning, just like our coin toss earlier, there is a one in three chance of guessing correctly. However, there is a difference both in the likelihood of each bet winning and its subsequent House Edge.

This is shown in the table below:

Baccarat House Edge

The Banker bet statistically has the slightly higher chance of winning, therefore, the House Edge is the lowest. The Player bet is not far behind with a slightly higher House Edge.

The Tie Bet in Baccarat happens rarely, so it has a high House Edge. However, to compensate it usually offers a higher payout when it lands.

If you bet £100 on the Player Bet, then you would get a return of 1:1 minus the house edge of 1.24%. So your total win would be £98.76 (100 minus 1.24) plus the £100 stake giving a total of £198.76.

House Edge In Slots

Casino Slots also have a House Edge, however, this is usually referred to in a different way.

With table games, the House Edge refers to what the casino return will be over a large sample of players. However, slots do the opposite by stating what the Return to Player, or RTP will be.

However, both of these things refer to different parts of the exact same sum.

RTP is what players can expect to get back from wagering £100 in a slot machine and it is given as a percentage figure.

Of course, just like House Edge, this is taken over a huge sample and is not guaranteed for individual players.

The higher the RTP, the lower the House Edge. Consequently, the better it is for the player.

If House Edge is 5%, then RTP is 95%.

If RTP is 98%, then House Edge is 2%.

Most slot games have an RTP of 90 – 98%, so it pays to play slots with the highest RTP to keep House Edge as low as possible.

Here are some examples of popular UK slot games in the UK with RTP.

How To Calculate House Edge

Calculating House Edge might seem a little daunting, but in effect it’s just applying mathematics to each game.

Let’s go back to the game of roulette for this example.

In single zero roulette, there are 37 total possible outcomes on the board – Numbers 1 to 36, and the single 0.

If you bet £1 on every single outcome, your total spend would be £37. The game pays 35-1 for exact numbers, so whatever number it lands on you will win £35 plus the £1 stake, meaning you will receive £36.

The difference between your £37 spend and £36 return is £1 which is profit for the casino, even though you have bet on the winning number.

You can then calculate the House Edge by taking the £1 profit, dividing it by the £37 risk and then multiplying it by 100.

£1 (casino profit) /£37 (player risk) = 0.0270 x 100 = 2.70%

You can then apply the same mathematics to ‘Double 0’ and ‘Triple 0’ roulette.

£2 (casino profit) /£38 (player risk) = 0.0526 x 100 = 5.26%

£3 (casino profit) / £39 (player risk) = 0.0769 x 100 = 7.69%

Of course, the easiest way to calculate House Edge is to find the RTP of a game. The RTP can then just be subtracted from 100 and whatever is left is the House Edge.

This means you can work out the RTP and House Edge of any casino game by knowing just one of these figures.

Which Casino Games Have The Lowest House Edge?

House Edge shouldn’t be the only thing to consider when choosing your casino games. Afterall, casino play is meant to be fun. So don’t just play a game because it has a low House Edge, choose it because you enjoy it.

However, if you want to play casino games that in theory give you a better return, then it is worth considering House Edge and RTP.

Casino Game House Edge

Don’t forget though, that both the House Edge and RTP figures are taken over a huge sample of data and individual player experiences can be vastly different.

It doesn’t take into account side bets on table games or the volatility and variance of slot games either.

How Can You Turn The Casino Edge In Your Favour?

Casino advantage play is a way of turning casino game odds in your favour, rather than the casino’s favour and is a form of Matched Betting.

Matched Betting uses casino offers and promotions to a player’s advantage. Each offer is analysed for its potential value and assessed as to how it should be played to give the player the best possible return.

Players are then provided with strategies and guides to help them complete the offer to get the best outcome. In some cases, this can result in guaranteed profits provided you follow the instructions correctly, while in other cases it gives players the edge over the casino where possible.

You can find out more about making money from casino offers here.