A casino is a gambling establishment, usually featuring a wide variety of games of chance and some requiring skill. These buildings can be very elaborate, with fountains, towers and replicas of famous landmarks. They are also designed to make patrons feel that they are entering a special world, where the rules of probability do not apply.

A major concern of casino owners is security. A high level of surveillance equipment is used to watch table games and patrons, and a separate room filled with banks of security monitors is set up to watch the floor. The security cameras are adjusted to focus on suspicious patrons by people in the monitoring room. In addition, the casino has employees to monitor players and bets. The staff tries to spot a player attempting to cheat by palming, marking or switching cards and dice. They also look for a pattern of bets that could signal the attempt to steal chips from another player.

Gambling has been popular throughout history, and casinos have played an important role in many societies. Initially, they were places where people could gamble on games of chance, but over time they have evolved into entertainment centers with restaurants, bars and other facilities. Casinos are legal in many countries, and in the United States, they can be found in Las Vegas, Atlantic City and on American Indian reservations, which do not have state antigambling laws. Many casinos are operated by organized crime groups, which have a long history of drug dealing, extortion and other illegal activities.