A casino is a gambling establishment where patrons can place bets on various games of chance. Casinos are most commonly located in cities with legalized gambling, such as Atlantic City, Nevada, and Macau, China. Many states in the United States have changed their laws in the latter half of the 20th century to permit casinos. Some American Indian reservations also have casinos, which are not subject to state antigambling laws.

Gambling has long been an integral part of human culture, from ancient Mesopotamia and Greece to Napoleon’s France and Elizabethan England. Modern casino gambling takes many forms, from slot machines and blackjack to live table games and bingo. Despite the widespread availability of casino-style games, there are still people who do not gamble for fear of becoming addicted or because they believe that gambling is immoral.

Casinos typically have a house edge and variance, two mathematical measurements that determine the probability of a game winning or losing. These calculations are made by gaming mathematicians and computer programmers, who are called gaming analysts. The results of these analyses inform how much money a casino needs to maintain its operating budget, and they are used to calculate the odds of specific games.

Most modern casinos have both physical security forces and a specialized surveillance department, which monitors the activities of the casino’s patrons by closed circuit television or another surveillance method. A number of casinos also have catwalks that run through the ceiling and allow surveillance personnel to look directly down on tables and slots from above.