According to the American Gaming Association, about 51 million people over 21 years of age visited casinos in 2002. Many of those casino visits were to places like the Mauro Codussi-designed Casino di Venezia, which sits on the Grand Canal and welcomes guests with a free boat shuttle service. But despite the glitz and glamour, it is important to remember that casinos are not charitable organizations that are giving away free money to anyone who walks through the door. Casinos have built-in advantages that ensure the house will win most of the time, and those odds aren’t based on luck or skill.

The advantages that a casino gains are known as the house edge, and they are built into the rules of each game. This advantage isn’t a matter of chance, but rather a mathematical expectation that the casino will make more money than it will lose, even after paying all of its employees and operating costs. As such, most casinos don’t take the risk of losing more than they can afford to pay out in winnings.

In addition to ensuring their games are fair, casinos rely on security measures like cameras and other electronic devices. They also enforce their rules of conduct with employees who watch patrons closely for signs of cheating or stealing, both in collusion with fellow casino staff and independently. They can also spot patterns in betting that might indicate the use of marked cards or dice.