A place where people gamble on games of chance or, in some cases, skill. Casinos usually earn money by charging a commission on winning bets, called the rake. They may also provide complimentary items or entertainment to patrons.
In the United States, casinos first appeared in Atlantic City and, in the 1980s, began to spread throughout the country as state laws were changed to permit them. They have also appeared on American Indian reservations, where state antigambling laws do not apply. The casinos are often large, lavishly decorated buildings. The glitz and glamour of casinos are often used as a draw for tourists.
Although gambling is the primary business of most casinos, they also offer other services such as restaurants and bars. They are also a major source of revenue for local governments, especially in cities such as Las Vegas. They may also host concerts and other events.
The large amount of money handled within a casino makes it vulnerable to cheating and theft by both patrons and staff, either in collusion or independently. To counter this, most casinos have security measures. These include security cameras, a full-time security manager, and a strict code of conduct for employees.
Most casinos have a mathematically determined expected value that ensures the house has a profit, or house edge, on all bets placed by customers. The size of this advantage varies by game. In games that involve an element of skill, such as blackjack, the house edge is known precisely as the expected value resulting from optimal play (not including card counting). Roulette wheels and dice are electronically monitored to discover quickly any statistical deviations from expected results.