A casino is a building or room where gambling takes place. It is also a term used for the games themselves, such as roulette, blackjack, craps, and poker. A casino can also refer to a gambling establishment operated by an Indian tribe, which is exempt from state gaming laws. The casino industry is a major source of revenue in many countries, and its growth has outpaced that of most other industries. Casinos are often combined with hotels, restaurants, retail shops, and entertainment venues.

Most casino games involve a combination of chance and skill, although some, such as poker, have a significant strategy element. Casinos make money by taking a percentage of all bets made, or in some cases the entire pot of money wagered, and this is known as the house edge. In addition, casinos charge a commission on some bets, called the rake.

While modern casinos use a variety of entertainment to draw in customers, gambling remains their primary business. In the United States, nearly all casinos are located in states where gambling is legal, and most are regulated by either the state or federal government. Casinos also operate in foreign countries, and are sometimes run by private companies.

Casinos compete to attract big spenders by offering complimentary goods or services, called comps. For example, in the 1970s, Las Vegas casinos gave away free rooms, buffet passes, show tickets and even airline tickets to their best gamblers. Today, casino owners are choosier and concentrate their investments on high rollers, who gamble for much more than average amounts of time and money.