A casino is a building or room where gambling games are played. The precise origin of gambling is unknown, but it is believed that it has been a part of human culture for thousands of years. In modern times, casinos have become a major source of entertainment and tourism. Casinos are regulated by law to ensure that the public is protected from cheating or theft. The security measures taken by a casino include surveillance cameras and guards. In addition to these, some casinos offer shows and fine dining to attract more customers.

The United States has the most casinos of any country in the world. Most of these are located in Atlantic City, New Jersey, and Las Vegas. A few casinos are also on American Indian reservations, which are exempt from state antigambling laws. Casinos have a variety of games, including slot machines, blackjack, and roulette. Most of these are based on chance, but some involve skill. Casinos make money by charging a percentage of total bets to the players, called a house edge. In addition, they may give out free goods or services to high rollers, such as rooms and meals.

Casinos have long been a target of organized crime. In the 1950s, mob money helped expand the gaming industry in Nevada. However, the mob was unable to control these businesses. Real estate investors and hotel chains realized the potential profits of casinos and began buying out the mobsters. Federal crackdowns on mob influence at the casinos helped deter future mob involvement.