A casino is an establishment where patrons can gamble on games of chance. It is one of the most popular forms of gambling, especially in the United States, where it is legalized in all 50 states and the District of Columbia. In addition to gambling, a casino can also host entertainment events like concerts and stand-up comedy shows. Casinos are usually located in or combined with hotels, resorts, restaurants and retail shopping. Some casinos specialize in specific types of gambling, such as craps and roulette, while others feature a wide variety of games.

While gambling probably predates recorded history, the modern casino is a relatively recent invention. It developed during the 16th century, when a gambling craze swept Europe. At the time, aristocrats would hold private parties at houses known as ridotti [Source: Schwartz]. These social gatherings were often held in violation of the law, but the aristocracy could afford to ignore the authorities. The casino concept grew from these private clubs and eventually spread to public venues, where people could find many different ways to place bets and win money.

Because large amounts of money are handled within a casino, both patrons and staff may be tempted to cheat or steal, either in collusion with each other or independently; for this reason casinos employ a variety of security measures. These include a high-tech “eye-in-the-sky” system that monitors every table, window and doorway; and elaborate slot machine payout systems that can be adjusted by security workers to focus on suspicious patrons.