A casino, or gaming establishment, is a building or room where people can gamble on games of chance. Most casinos offer a variety of gambling options, including table games like blackjack and roulette, as well as slot machines and video poker. In addition, some casinos specialize in certain kinds of gambling, such as horse racing and keno.

Many casinos use technology to track patrons’ actions, as well as to monitor and control the games themselves. For example, some casinos employ “chip tracking” systems whereby the betting chips have built-in microcircuitry that allows the casino to oversee the amounts wagered minute-by-minute and to immediately discover any anomaly; the same kind of electronic monitoring is used on the roulette wheels to detect any deviation from their expected averages. Other technologies are used to prevent cheating and stealing, either in collusion between patrons or by casino staff.

In the United States, the vast majority of casinos are located in Las Vegas and Atlantic City, with a small number in Chicago and other cities. However, casinos have also become established on Indian reservations, which are exempt from state antigambling laws.

Several cities are known for their casinos, such as Monte Carlo in Monaco, and the island of Malta has a casino at the Dragonara Palace, which was built in 1870. In the 21st century, casinos have become more widespread worldwide. In Europe, a few countries (including the UK) have legalized casinos. Others, such as the US state of Nevada, permit casino-style gambling.