A casino, or gaming house, is a place where people can gamble. Various games are played there, such as poker, blackjack, craps and roulette. There are also often a variety of slot machines. In modern casinos the emphasis is on gambling, but there are also restaurants and other entertainment. Many states have legalized casinos, and many American Indian reservations have their own facilities. Casinos are generally staffed by professional security personnel and have elaborate surveillance systems. Some casinos have cameras in the ceiling that can be adjusted to focus on suspicious patrons.

In addition to cameras, casino security uses rules and conduct to discourage cheating. For example, players at card games are required to keep their cards visible at all times. The walls and floors are usually painted in bright, sometimes gaudy colors to stimulate the senses and encourage people to gamble. Often there are no clocks on the walls, because it is believed that they can distract gamblers from keeping track of time.

A casino’s primary source of income is the vig, or house advantage, built into each game. This edge can be small, but it adds up over millions of bets and allows a casino to make money even when the majority of bettors lose. As a result, casinos have enough money to build extravagant hotels, fountains and replicas of famous landmarks. They can also afford to offer comps to big bettors, which can include free hotel rooms, dinners and tickets to shows.