There are many reasons to visit a casino: the entertainment, the shopping and, of course, the gambling. While musical shows, lighted fountains and elaborate hotels help bring in the crowds, casinos would not exist without games of chance such as slot machines, roulette, blackjack, craps, keno and baccarat. These games give the casinos a mathematical advantage that generates billions of dollars in profits each year for the companies, investors and Native American tribes that own and operate them.

Casinos are often built near or combined with hotels, resorts, restaurants, retail shops and cruise ships. They may also feature live entertainment such as stand-up comedy, concerts and sports events. Many casinos in the United States are owned by corporations, while others are operated by local governments, tribes or private individuals. Some are open 24 hours a day, while others are limited to certain periods of the day or week.

Although gambling probably predates recorded history, the casino as a gathering place for various forms of betting emerged in Europe during the 16th century with the development of the ridotti (small private rooms). In the modern sense of the word, a casino is any large building or room where people can find a variety of ways to gamble under one roof. Because large amounts of money are handled within a casino, both patrons and employees may be tempted to cheat or steal, either in collusion or independently. This is why casinos spend a great deal of money on security.