A casino is a building or room in which people can gamble on various games of chance. The term is often associated with the gambling meccas of Las Vegas and Reno in Nevada and Atlantic City in New Jersey, although legalized casino gambling has expanded to many other places. Many of these casinos have hotels, restaurants and other amenities. The biggest casino in the world is WinStar World Casino in Thackerville, Oklahoma, with a total area of 600,000 square feet. The second and third largest are the Venetian Macao and City of Dreams in Macau, China.

The primary source of revenue for a casino is the vig or rake, which is a percentage of each bet placed. This is in addition to the profits generated by the games themselves, which are designed with a built-in advantage for the casino. This advantage can be very small, but millions of bets can add up to significant profits. These profits can be used to pay for elaborate hotels, fountains, towers and replicas of famous landmarks.

Casinos often reward big bettors with free merchandise and services, including hotel rooms, meals and shows. These rewards are known as comps. In order to qualify for these incentives, players must ask a casino host or employee how to get their play rated.

Some critics argue that the net effect of a casino on a community is negative, because it diverts spending from other forms of entertainment and causes problems for people who are addicted to gambling. The cost of treating problem gambling and lost productivity due to compulsive gambling can cancel out any profits the casino may generate.