The standard definition of the casino's house advantage is the ratio of the expected player loss to the amount they have initially wagered. Finding the games with the lowest house edge is what is important for the players, so that they could exploit the game and draw profit from it. So, in order for the casino to make profit, the games use a law of averages, in which they are provided with just a few percent advantage that would give them a chance to generate winnings in the long run.

In other words, casinos make their money because of a built-in advantage that allows them to “outplay” their customers. The truth is that casino's income is not generated thanks to pure luck, but because of the so-called “ house edge” or house advantage. Learning what house edge is, is considered a key part of understanding not only craps but any casino game a player could be interested in.