A casino is a gambling establishment that offers a variety of games of chance. Customers place cash or chips on various possible outcomes of a game, and the house takes a percentage of all winnings. This advantage is called the house edge. Some casinos also offer a number of other betting options, including poker and horse racing gambling. These activities are regulated by law in most jurisdictions. The term casino may also refer to a large building used for such purposes, or to a group of casinos in a particular city.

Historically, the most famous casinos were located in Europe, where they were often designed as elaborate playgrounds for wealthy European royalty and aristocracy. For example, the elegant spa town of Baden-Baden was built around its casino, which Marlene Dietrich once referred to as “the most beautiful in the world.”

Modern casinos are usually heavily computerized. Video cameras and computers are used for general security, and they are also routinely used to supervise individual games. For instance, in “chip tracking,” casino employees use special chips with built-in microcircuitry to communicate with electronic systems that oversee the exact amount wagered minute-by-minute; and roulette wheels are electronically monitored regularly to discover any statistical deviations from expected results.

Gambling is big business worldwide and casinos exist in nearly every country. The United States leads the pack, with some 2,147 casinos across 920 gambling cities. The American Gaming Association estimates that the casino industry contributes $261 billion to the economy each year.