A casino is an establishment for gambling. Casinos are often built near or combined with hotels, restaurants, retail shops, and other tourist attractions. Many cities host large casinos, and a number of countries have legalized them. They often feature table games like blackjack and roulette, as well as slot machines and other electronic gaming devices. Some casinos also offer live entertainment such as musical performances and stand-up comedy.

In the United States, where gambling is legal, most casinos are owned by corporations or individuals. A few are operated by government-owned or tribal entities. In most cases, the owners of casinos do not control the operations. A casino’s earnings are generated primarily by patrons’ gambling activities, but casinos may also earn money through non-gambling business such as food and beverage sales, hotel rooms, and spa services.

Most modern casinos use specialized security systems to detect and deter crime. These typically include a physical security force and a dedicated surveillance department. In some casinos, security cameras are positioned on catwalks that extend above the gaming floor and allow surveillance personnel to look directly down, through one-way glass, on the action at tables and slots. Casinos also hire mathematicians to calculate the expected house edge and variance for each game. This information allows them to quickly discover any statistical deviations from expected results. These deviations, known as hot and cold streaks, can dramatically decrease a casino’s profitability. Casinos thus strive to maintain a constant house edge, or at least avoid substantial losses over time.