A casino is a gambling establishment, a building or room where people can gamble. The word is also used for the games played in such places, including craps, roulette, baccarat, blackjack, and video poker. In addition to the games of chance, some casinos offer entertainment shows or other attractions such as restaurants and bars. These activities are intended to offset the negative impact of gambling on the local economy.

A significant portion of the profits generated by a casino is the result of a mathematical advantage the house has over patrons, which can be expressed more precisely as the house edge. The house edge is built into all games of chance, and can be found by examining the math behind them; in games with an element of skill such as poker, it is a percentage of the total amount wagered, known as rake.

Although gambling probably predates recorded history, the modern casino as an institution offering a variety of ways to gamble under one roof emerged in the 19th century. The classic example is the Casino at Monte Carlo, which opened in 1863.

In the United States, casinos have been a major source of revenue for many cities and towns, especially those near water. They have also become tourist attractions in their own right, and some are even incorporated as resorts or hotels. In the 1980s, they began appearing on American Indian reservations, which are exempt from state antigambling laws.