A casino, or gaming hall, is a facility for playing games of chance. It also offers a variety of other entertainment options, including restaurants, bars and meeting space. Modern casinos often combine gambling with luxury hotels and retail shopping, but the vast majority of revenue still comes from the games themselves. The popularity of slot machines, blackjack and roulette generate billions of dollars in profits for casinos every year.

The precise origin of gambling is unknown, but it is widely believed that the game has existed in some form since ancient times. The first casinos developed in the 16th century during a gambling craze that swept Europe. Italian aristocrats would hold private parties at venues known as ridotti, where they could gamble in relative privacy. The casinos of the time were not technically legal, but the risk of a mob attack meant that the houses were rarely bothered by police.

In the 21st century, casinos have grown to become a worldwide phenomenon. Although most countries changed their gambling laws in the latter half of the 20th century, many of these casinos still follow a similar structure. The modern casino is more like an indoor amusement park than a traditional gambling establishment, with the emphasis on entertaining the clientele. The most famous casinos are located in Las Vegas, Atlantic City and Chicago, but there are a number of smaller establishments around the world. Casinos offer a huge selection of games, including a wide range of slots, table games and video poker.