A casino, also known as a gambling house or gaming house, is an establishment where people can gamble. Its size and scope vary greatly, from a small building housing a single table to huge complexes featuring multiple gaming floors, restaurants, bars, and entertainment venues. Some casinos offer only slot machines and other electronic games, while others combine these with traditional table games such as blackjack and roulette. In some cases, casinos are regulated by law to ensure their fairness.

Most casino games depend largely on chance, but some require an element of skill. The mathematical expectation of winning or losing at each game is determined by the casino’s rules, and is known as the house edge or expected value. The casino’s profit comes from the difference between the house edge and the player’s bet. In games where the players compete against each other, such as poker, the casino earns money through a commission called the rake.

In the twenty-first century, many casinos are focusing on high-stakes gamblers who spend large amounts of money and often gamble for extended periods. These high rollers are often given free luxury suites, meals, limo service and other inducements in return for their substantial wagers.

Casinos use a variety of techniques to prevent cheating and other illegal activities. The simplest method is to have all casino employees keep their eyes open for suspicious patrons, and the more sophisticated methods involve video surveillance. Elaborate surveillance systems allow security workers to watch the entire casino floor from a room filled with banks of monitors. The system can even be adjusted to focus on specific suspicious patrons.