A casino (also called a gambling house or a gaming room) is an establishment offering various types of gambling. Modern casinos offer a variety of games and gambling opportunities, including slot machines, table games like blackjack and roulette, and sports betting. Some casinos also have live entertainment and other events. Casinos can be located in cities, on cruise ships or in resorts.

In the United States, casinos are legal in 40 states and operate more than a thousand gaming locations. Most of these facilities are operated by commercial or Native American casino owners, with the largest one being the Foxwoods Resort Casino in Ledyard, Connecticut. A large number of people visit casinos for entertainment or to gamble. Some of these visitors are locals, and others travel from nearby states or countries. The casinos generate billions in revenue each year.

Most casino games have an element of chance and some have a skill component, such as poker. Casinos earn money by charging a commission on certain games, known as the rake. This is often the only source of profit for the casinos, and some are more profitable than others.

Due to the large amounts of money handled by casino patrons and employees, fraud and theft are common problems in these establishments. To mitigate these risks, casinos employ a variety of security measures. These include a physical security force and a specialized surveillance department. Moreover, most modern casinos are wired for video surveillance and other electronic monitoring systems. Chip tracking systems allow casinos to supervise the movements of betting chips minute-by-minute, while roulette wheels are electronically monitored for statistical deviations.