A casino, also known as a gambling house or gaming hall, is an establishment for certain types of gambling. Casinos are most often found in cities with large populations, such as Las Vegas, Reno and Atlantic City. Many states have laws regulating the operation of casinos. The casino industry is a major source of employment in some places.

Casinos have several security measures to prevent cheating and theft by patrons and employees. These include a network of cameras that cover the entire casino floor, as well as a separate room filled with banks of security monitors where staff can watch for suspicious behavior. In addition, there are trained game analysis mathematicians on hand to spot any deviations from the expected outcomes of a particular table game.

Something about the nature of casinos, with their large amounts of cash and high stakes, seems to encourage people to cheat and steal. In some cases, this is done in collusion with casino staff, but it can also be a solo or group effort by patrons. Because of this, most casinos invest a significant amount of time and money into security.

As a result, the most popular gambling games in casinos have become highly developed and sophisticated. For example, roulette wheels are electronically monitored minute by minute to detect any statistical abnormalities. Card games like blackjack and poker have established strategies that can reduce the house edge to less than a percent with optimal play.