A casino is a business that sells chances on games of chance. Whether it’s slot machines, blackjack, craps or keno, casinos make billions of dollars each year from gambling. They are also known for their lavish hotels, restaurants, entertainment and shopping.

Gambling almost certainly predates written history, with primitive protodice (cut knuckle bones) and carved six-sided dice found in the oldest archaeological sites [Source: Schwartz]. But the concept of a place where gamblers could find all types of games under one roof did not develop until the 16th century, when the Italians popularized it in their casinos, called ridotti. These were small clubhouses where aristocrats met to socialize and gamble, even though gambling was technically illegal.

The modern casino is much like an indoor amusement park, with most of its entertainment and profits coming from gambling. It has all the trappings of a modern resort, from elaborate themes to musical shows to elaborate hotels and shopping centers. But it would not exist without the billions of dollars that people bet on slot machines, roulette and other table games each year.

To ensure that they remain profitable, casinos employ a variety of methods to prevent cheating and other forms of collusion. They use surveillance cameras to monitor players and enforce strict rules of conduct. They also use comps, or complimentary goods and services, to reward loyal customers. Typically, these include free hotel rooms, meals and tickets to shows and events. In some cases, they go as far as limo service and airline tickets.