A casino is a gambling establishment that offers games of chance and other entertainment. Some casinos are integrated with hotels, restaurants, retail shopping and other attractions, but most are standalone establishments devoted to gambling. Many states have legalized casino gambling, with Nevada and Atlantic City being the most prominent destinations. Some casinos also offer sports betting and horse racing.

A modern casino is often a massive structure that includes a variety of gaming tables and slot machines. It may also feature stage shows, restaurants and other luxury amenities. Historically, however, casinos have been less elaborate, relying on the innate excitement of games of chance to attract patrons.

While gambling probably existed long before recorded history, the casino as an institution offering a variety of ways to gamble under one roof did not develop until the 16th century during a European gambling craze. Prior to this, people would gather in private clubs known as ridotti to gamble and socialize.

Casinos make their money by charging a percentage of bets placed by patrons on various games of chance. The house edge of a particular game can vary, but it is uniformly negative from the perspective of the player and is calculated based on mathematical odds. Some casinos add an additional element of profit by taking a fixed percentage from players at card games, such as poker or blackjack. This is sometimes called a vig or rake. Because large amounts of money are handled within a casino, staff and patrons are sometimes tempted to cheat or steal, either in collusion or on their own. This is why casinos spend a lot of time and money on security.