The house edge, which is built into every game, helps to ensure that casinos are not losing money on their operations. As such, it is a critical piece of a casino’s business model. The exact math that goes into each game varies, but the general rule is that the house always wins in the long run.

It’s an interesting question to consider why a group of rational people—people who work hard for their incomes and make reasoned financial decisions on a day-to-day basis—would spend hundreds or thousands of dollars at a casino, simply based on the spin of a wheel or roll of the dice. The answer to this question is complex, but it boils down to two key factors.

One factor is that, despite what we may think as humans, our brains are very good at finding patterns in randomness. When we see a pattern, our brains automatically assume that it will continue. This is why we often find ourselves on the edge of a precipice when we are gambling, even though we know that it could turn out to be our last bet.

The other key factor is that, if we feel like we are gaining an advantage, we tend to stick with it. This is why gamblers are often rewarded with free spectacular entertainment, transportation, elegant living quarters and other inducements for their high-dollar wagers. This is not to suggest that casino patrons are stupid or greedy, but that their brains are wired in a way that makes them want to keep playing.