A casino, also known as a gambling house or gaming establishment, is a place where people can go to gamble. Most casinos offer a wide range of games of chance and some even feature skill-based games. Some states have laws that regulate the operations of casinos, while others simply license them. The games of chance offered in a casino are controlled by a house edge, which is the expected loss to the player over time. Some casinos even collect a commission or vig on some games, especially those in which players compete against each other, such as poker.

In modern times, the term casino has come to refer specifically to a large building that houses one or more gaming tables. The interior design of a casino is meant to create an atmosphere that maximizes chances for success, while making the patrons as comfortable as possible. For example, a casino might have lavish carpeting and well-designed lighting to evoke excitement.

There have been a number of attempts to regulate casinos, and some states have even banned them. However, most states now allow casinos to operate. Some casinos are located on American Indian reservations and are exempt from state laws. Other casinos are found on cruise ships and in foreign countries.

Most casinos make a large portion of their profits from slot machines. These machines accept paper tickets with barcodes and have varying bands of colored shapes that roll on reels (physical or video). If the right combination appears, the player wins a predetermined amount of money. While these machines may seem simple, there is considerable mathematical complexity behind them.