A casino is a gambling establishment where patrons can engage in various forms of gambling. It offers a variety of games, most of which involve chance and some of which require skill. Most casinos offer restaurants, free drinks and stage shows. Some of the larger casinos have fountains, replicas of famous buildings and even a tower. Most of the time, the casino’s security is divided into a physical force that patrols and responds to calls for assistance or reports of suspicious or definite criminal activity and a specialized surveillance department that operates the closed circuit television system known as the eye in the sky.

In the United States, casinos are most concentrated in the Las Vegas Valley and Atlantic City, although there are a few in Chicago and other cities. The most popular casino games are slot machines, which account for a large proportion of the billions of dollars in revenue raked in by casinos each year. Table games like blackjack, craps, roulette, baccarat and poker make up the rest of the revenue. All of these games have a mathematically determined advantage for the house, which is known as the house edge. Casinos take several steps to counter this, including offering free food and drink, and using chips instead of real money to make the game more abstract, which makes players less concerned about losing money. Many casinos also have ATM machines on the premises. Because of the large amount of money handled in a casino, both patrons and staff may be tempted to cheat and steal, either in collusion or independently. Modern casino security is designed to prevent this, and most casinos have extensive video surveillance on the premises.