A casino is a place where people can gamble on games of chance. While musical shows, lighted fountains and shopping centers help draw in the crowds, the vast majority of a casino’s profits come from gambling. Slot machines, blackjack, roulette and craps account for most of the billions of dollars that casinos rake in each year.

The exact origin of gambling is unknown, but it’s believed to have been around for thousands of years. Some of the earliest known casinos were on American Indian reservations, which were exempt from state anti-gambling laws. The first legal casinos opened in Atlantic City, New Jersey, in 1978, and during the 1980s they spread to other states and to American Indian tribal lands.

Casinos make money by ensuring that every game they offer has a built-in statistical advantage for the house. This slight edge, called the vig or rake, can be minuscule, but it adds up over the millions of bets placed in a casino each day. This virtual guarantee of gross profit allows casinos to spend large sums on extravagant inducements for big bettors, such as free spectacular entertainment, reduced-fare transportation and elegant living quarters.

Many games have specific rules that must be followed in order to play the game properly. A casino’s employees are trained to look for blatant cheating, such as palming or marking cards or switching dice. In addition, casinos use cameras and other surveillance equipment to watch patrons.