A casino is a gambling establishment that offers patrons a variety of ways to gamble, in some cases with an element of skill. The term is most associated with Las Vegas and its casinos, although they have become popular in many other locations, especially since the 1980s when a number of American states legalized them. They are also found on American Indian reservations, which avoid state anti-gambling laws, and in some other countries where gambling is legal.

A gambling hall must be attractive to attract players, and its layout is designed with that in mind. It must offer a variety of games, and be large enough to hold a significant number of people at once. The lighting is also important-more than 15,000 miles (24,100 km) of neon tubing is used to light the casinos along the Las Vegas strip. Sound and sight are also used to entice gamblers. The noises of slot machines, bells and the clang of dropping coins are all intended to lure people in and the sights of games such as blackjack, baccarat and video poker are designed to be appealing to humans’ visual senses.

Casinos must be secure, and they rely on elaborate surveillance systems to detect cheating or other problems. In table games such as baccarat, the dealers are heavily trained to look for any blatant signs of cheating; in roulette, the wheels are electronically monitored regularly to discover statistical deviations from expected value. The casinos themselves are protected by a layer of security that includes armed personnel and roving patrols. Some casinos use electronic surveillance that gives the casino a high-tech “eye-in-the-sky” that can monitor tables, windows and doors from a remote control room.