A casino, also known as a gambling house or a gaming hall, is an establishment where people can gamble and enjoy various entertainment. Generally, casinos are built near or combined with hotels, restaurants, retail shops and other tourist attractions. Many casinos offer free or discounted meals, drinks and shows. A casino may be run by a single company or it can be owned by an organization such as a resort, hotel chain, or professional sports team.

Gambling probably predates recorded history, with primitive protodice and carved six-sided dice found in archaeological sites. But it took until the sixteenth century for casino games to develop into a place where patrons could find a variety of ways to gamble under one roof, thanks to the emergence of an enormous gambling craze in Europe. The first official casino opened in 1638 in the Venetian Church of San Moise. It was a private club for the rich, called a ridotto. The club was not bothered by legal authorities, as gambling was considered a legitimate pastime by the aristocracy of the time.

Gambling is a game of chance, but there is some skill involved in some games, such as blackjack and poker. The odds are always against the player, however, as the house has a mathematical advantage over each player that is equal to the expected value of the bets they make (or lose). Casinos also profit from players who make large bets or play for long periods of time, because those players are often comped (gifted) items or services such as free hotel rooms, dinners and tickets to shows.