A casino (or gambling house) is a place where people can gamble. Many casinos are connected to hotels, resorts, restaurants, retail shops, and other tourist attractions. Some casinos are also known for hosting live entertainment, such as concerts and sports events. Some casinos are open 24 hours a day.

A number of tricks are used to attract and keep patrons at a casino. Bright colors are often used, as they have a stimulating effect. More than 15,000 miles (24,000 km) of neon tubing light the casinos on the Las Vegas Strip. The noises of slot machines and the clang of coins dropping are designed to appeal to human senses.

In the early twentieth century, as states legalized gambling, large casinos opened. These casinos, which were sometimes combined with hotels and other facilities, drew visitors from all over the world. The casinos grew so successful that they attracted organized crime figures, who began taking over them. Mob money gave casinos a taint that caused legitimate businessmen to hesitate to get involved. But once hotel and real estate developers realized the potential profits, they bought out the mobsters and removed the taint from casinos.

Most casinos offer a wide variety of games. Some even feature multiple betting options, including moneylines, point spreads, over/unders (totals), and props. Some of the most popular casino games are blackjack, roulette, and poker. Many casinos also feature a variety of live dealer games, which allow players to interact with each other and the dealers in real time.