A casino is an establishment that offers the opportunity to gamble. It may also offer food and drink, entertainment and other amenities to its patrons. The casino industry is a major source of revenue in the United States, with about $6 billion bet every year within its walls. It is estimated that there are more than 3,000 legal casinos worldwide. Casinos are operated by a variety of organizations, including state governments, Native American tribes and private corporations. In the United States, casinos are primarily found in Las Vegas, Nevada; Atlantic City, New Jersey; and Puerto Rico. Casinos may also be located on some American Indian reservations, which are exempt from state antigambling laws.

Casinos are essentially gambling halls, with most of their profits coming from games of chance such as blackjack, poker, roulette and craps. These games have mathematically determined odds that give the house an edge over the players, which can be minimized by skillful play. Casinos may also compensate patrons for their losses by offering free goods and services, known as comps.

In addition to table games, most modern casinos offer a wide variety of electronic gaming machines, such as video poker and slot machines. Some casinos specialize in certain types of games, such as baccarat and sic bo. In Asia, casinos often feature traditional Far Eastern games such as pai gow and fan-tan. Modern casinos have a strong emphasis on security, with physical security forces patrolling the premises and a specialized surveillance department that operates a closed circuit television system known as an eye in the sky.