It’s happened to everyone: You stride into the Luxor, Mohegan Sun or Tropicana brimming with confidence and a wallet full of cash, and you plan a bit of enjoyable, sensible gaming and maybe two rounds of drinks. But hours later you have no idea what time it is, how many chips you’ve lost or where your money went. You’re a victim of one of the casino’s many blatant and subtle tricks to keep you gambling.

Casinos make money because every game has a built in statistical advantage for the house. The margin may be very small — lower than two percent on average, in fact—but over millions of bets that edge adds up to a nice profit. That’s enough to finance the giant pyramids, fountains, towers and replicas that decorate them, as well as the high-end restaurants, boutiques and spas that attract people from around the world.

Moreover, casinos often entice their patrons with comps like free rooms and meals. And they’re smart to hone in on gamblers who are most likely to spend large sums of money. For example, a casino might offer high rollers an exclusive area for games where the stakes are in the tens of thousands of dollars.

Casinos also help local economies. When they attract tourists they bring jobs and revenue to hotels, restaurants and attractions that cater to them. And if gamblers lose money they spend it on local products and services, too.