Casino is a place where people gamble and play games of chance. Modern casinos resemble indoor amusement parks with lighted fountains, shopping centers and elaborate hotels, but they would not exist without games of chance such as blackjack, roulette, slot machines and craps, which provide the billions of dollars in profits raked in every year.

Although some states have banned gambling, most have legalized it at least to some extent. Most casinos are located in Las Vegas, Atlantic City, and Reno, with smaller ones scattered throughout the country. A few American Indian reservations also have casinos.

Regardless of where they are located, all casinos have one thing in common: the house always wins. The mathematical expectation of each game gives the casino a built in advantage that, over time, ensures its profitability. This edge can be very small, lower than two percent, but it allows casinos to justify extravagant expenditures such as elaborate hotels, lighted fountains and towering replicas of famous landmarks.

Because of the large amounts of money involved, casinos are prone to theft by both patrons and staff. Security measures are therefore a high priority. Casinos use video cameras to monitor the casino floor, and computer systems supervise each game to ensure that the results match the expected values. Chip tracking enables casinos to oversee betting minute by minute, and electronic devices in roulette wheels allow them to discover any statistical deviation quickly.