Understanding the Game of Craps: Odds and House Edge

Casino players who decide to try their luck on the craps table should know how probable certain outcomes of the game are, as well as the house edge they would be up against. There are dozens of bets in this game and some offer significantly better odds than others.

Compared to other traditional table games such as roulette or blackjack, craps comes with a mathematical advantage that varies dramatically, depending on the number or group of numbers players decide to bet on. The majority of games have a house edge that is more or less fixed while in craps, this fundamental part of the game fluctuates from 1.41% to nearly 20%. This is why players should carefully choose what to bet on if they want to improve their overall chances of winning in this game.

The House Edge in Casino Games

Before craps players start placing real-money bets on this game, they should have a good understanding of what house edge is. It is a fundamental part of all casino games, bingo, lotteries, and, practically, all forms of gambling. This is the guaranteed advantage of the house over its patrons – with it, casinos manage to always generate profits even with the huge jackpots they regularly pay off. So, what exactly is the house edge and why is so important when playing craps?

House Edge
Return to Player

Relationship between Odds and Probability

1The Odds

To find the house edge of a certain bet in craps, players should know its odds – how likely it is to win or lose. Since craps is completely random and based on chance, the odds have a major, direct effect on the house edge. As mentioned above, the casino advantage is basically the difference between the true odds of a certain outcome and the payout offered, also called casino odds.

2The Probability

The payouts for the different bets may vary across casinos but the true odds of a bet are fixed and very similar to the probability for that bet to win. In a separate article, dedicated to the dice probabilities in craps, we have explained the similarity between odds and probability but in short, these two terms are used to express the same thing – the likelihood of an event occurring.

The probability for rolling a 7, for instance, is 6/36 since there are 6 possible combinations of the dice that can form a total of 7. All possible combinations, at the same time, are 36 because each of the two dice has six sides. This means that a roll of 7 is expected to happen around 16.67% of the time.

3How to Convert the Probability Into Odds

To convert the probability into odds, we just need to consider the possible combinations (6) for rolling a 7 and compare them with the rest of dice combinations (30) and flip the numbers. We will have 6 to 30, also expressed as 6:30, which is mathematically equal to 5:1.

How to Calculate the House Edge in Craps

There are various ways for calculating the house edge in a casino game – usually, it is the ratio of the expected player loss to the initial wager. One of the simplest formulas that can be used for craps, however, uses the general formula for the expected return. It combines the winning probability of an event multiplied by its return and the probability of losing multiplied by the lost initial bet:

Expected Return = {(ways to win*return) + (ways to lose*loss)}

So, what is the house edge for the Any 7 bet? This is a single-roll bet that is settled within a single roll of the dice – it wins if the dice land on any 7 (6 combinations) and it loses if the dice show any other total (30 combinations). Therefore, the equation for the expected return for this bet will look like this:

{(6/36)*4} + {(30/36)*(-1)}

Where 4 refers to the payout for Any 7 bet (4:1) and 30/36 shows that there are 30 combinations of the dice, which would lose. The negative number -1 is the bet we risk to lose. The calculation proceeds with 0.6666 - 0.8333 = - 0.1667. To receive the player’s edge, we divide the expected return by our initial wager and we come up with the same result as our initial wager is 1. Expressed as a percentage, the house edge is then 16.67%.

Line Bets
Single-Roll Bets
Multi-Roll Bets