A casino is an establishment for certain types of gambling. These include card games, table games such as blackjack and roulette, and video poker machines. A casino can also host live entertainment such as concerts and stand-up comedy. Some casinos are combined with hotels, resorts, restaurants, shopping areas, and/or other tourist attractions. Many states have legalized casinos, with Nevada leading the way for commercial casinos, and several American Indian reservations have casinos operated under state law.

Like any industry in a capitalist society, casinos exist to make money. They generate billions each year for the companies, investors, and Native American tribes that own and operate them, as well as for state and local governments that impose taxes and fees on casino revenues.

The majority of casino profits come from high rollers, who gamble large amounts of money and often receive comps (free rooms, meals, show tickets, etc.) worth thousands of dollars. According to a study conducted for the American Gaming Association by Peter D. Hart Research Associates and the Luntz Research Companies, 54% of American adults surveyed in 2004 found casino gambling acceptable.

Casinos are sometimes targeted for robbery and theft, either by customers or employees. Due to the large amounts of money handled within a casino, security measures are extremely important. Some of these measures are technological, such as cameras; others are more traditional, such as rules of conduct and behavior. In addition, casino employees are trained to spot signs of cheating or stealing.