A casino, also called a gaming hall or a gambling house, is a building where people can gamble. The games played in casinos are usually games of chance, in which the outcome depends on random events and, less frequently, games of skill, in which the players compete against each other (such as poker). In a game such as blackjack where players compete against the house, the casino earns money from each bet through a commission known as the rake.

Most casinos are located in areas with high populations of people who enjoy gambling. They are decorated in bright and often gaudy colors designed to stimulate the senses and entice people to gamble. Red is a particularly prominent color used in many casinos. The glitz and glamour of some casinos is intended to distract the patron from any negative aspects of the gambling experience.

Gambling in casinos is legal and is regulated by government authorities. Most countries have laws allowing citizens to gamble in licensed and supervised casinos. In the United States, most state jurisdictions regulate casinos. The casinos are primarily owned by private corporations, with some operated by Native American tribes.

The most successful casinos are those that offer a wide range of gambling opportunities and attract a variety of customers. In the twenty-first century, casinos are choosier about whom they let in, and focus their investments on the higher-stakes gamblers who generate most of the profit. These gamblers are offered a variety of extravagant inducements to come to the casino, such as free shows and transportation, and elegant living quarters.