From the glitz of Las Vegas to the illegal pai gow parlors of New York’s Chinatown, there are more than 100 million people–a quarter of all Americans over the age of 21–who visit casinos each year. Casinos may seem to be a place where only money matters, but the term actually encompasses a broad range of gambling activities.

In addition to slots, blackjack and poker, the typical casino offers such games as roulette, craps and baccarat. Gamblers wager a sum of money on the outcome of these games, and the house takes a percentage of the total amount wagered. This percentage is known as the house edge. In some cases, gamblers can reduce the house’s advantage by employing strategies.

Many casinos are run by real estate investors and hotel chains with deep pockets. The mob once owned a significant number of them, but federal crackdowns and the threat of losing their gaming licenses at any hint of Mafia involvement forced mobster operators out of the business.

Because of the large amounts of money involved, casinos are prone to corruption and theft by both patrons and staff. For this reason, most casinos spend a considerable amount of time and money on security measures. In addition, because of the nature of casino gambling–which is socially intoxicating and highly combustible–people are tempted to cheat and steal in collusion or independently. For this reason, a significant portion of the revenue generated by casinos comes from high rollers who are lavished with comps such as free or reduced-fare transportation and luxury living quarters.