A casino is a building or room in which gambling activities take place. Its purpose is to serve as a hub for a range of different gaming options, from poker to slot machines. A casino is not a social club, but rather a commercial operation that is licensed and regulated by the government. In the 21st century casinos have become a worldwide phenomenon and are found in cities throughout the world.
Almost all games at a casino have a mathematical expectation against the player, meaning that over time the house will make money. To counteract this, the casino must offer inducements to keep players coming back. These may include free spectacular entertainment, luxury living quarters, reduced-fare transportation, and other benefits.
In table games, such as blackjack and poker, the house earns money from a commission on bets called the rake. In poker, the casino also collects a percentage of winnings from each player called the tip. These amounts are typically small, but they add up quickly. A casino might hire professional mathematicians to help develop strategies that reduce the house edge, but this is not always possible or desirable.
In addition to their gaming operations, casinos have other revenue streams such as restaurants and entertainment. However, their primary source of income is from gambling. In the United States, a person must be at least 21 years old to enter most casinos. This age requirement is a response to the high incidence of problem gambling and related issues in younger adults.