A casino, also known as a gaming establishment or simply a casino, is a facility where people can gamble. The industry is regulated by government authority. Most casinos in the United States are located in places like Las Vegas, Nevada, Atlantic City, New Jersey, and Chicago. Some are on American Indian reservations, where state anti-gambling laws do not apply.

The casino industry is a worldwide business and has become the subject of numerous academic studies. Casinos are generally considered to be entertaining and profitable enterprises. However, their profitability depends on the ability of patrons to control their gambling habits and limit losses. In addition, they depend on the integrity of casino personnel and systems to prevent cheating or theft. Casino employees are trained to detect such activities and may be subject to disciplinary action.

Most casinos offer a variety of games, with the most common being slot machines and table games. These include blackjack, roulette, baccarat, and poker. Some casinos also have sports books and other non-gambling attractions such as restaurants, bars, and entertainment venues.

Some casinos use sophisticated technology to monitor the accuracy of their games. For example, table games use chips with built-in microcircuitry that interact with electronic systems to allow casinos to supervise the exact amounts wagered minute by minute and warn players of any abnormalities; roulette wheels are electronically monitored regularly for deviations from expected results. Casinos may also employ mathematical experts called gaming mathematicians to calculate the house edge and variance of their games.