A casino is a place where people can take chances on games of chance or skill. Some casinos are open to the public, while others require membership. In either case, the main attraction is gambling. A casino also may offer food and drink.
Something about the large amounts of money handled in a casino makes both patrons and employees tempted to cheat or steal, either in collusion with each other or independently. Therefore, most casinos invest a great deal of time and money in security measures. For example, some casinos have cameras on catwalks in the ceiling that allow surveillance personnel to look down through one-way glass at any table or slot machine in the casino. Others have chips with built-in microcircuitry that enable them to monitor betting patterns for any deviation from expected results.
In games where players play against each other, such as poker, the house takes a percentage of the total pot, which is called the rake. This income is the principal source of profit for casinos. In addition, casinos make substantial profits from the slot machines and (since the 1980s) video poker machines, which generate income from high volume, rapid play at sums ranging from five cents to a dollar or more.
Some casinos are located in cities with high populations, such as Las Vegas and Atlantic City, while others are on American Indian reservations or in other states that have legalized casino gambling. The number of casinos is increasing around the world, with Nevada leading the way. Despite the popularity of casinos, some economists argue that their net effect on a community is negative because they draw money away from other types of entertainment and may lead to compulsive gambling.