A casino (plural casinos) is a building where gambling games are conducted. Casinos also feature restaurants, bars and other entertainment options. Some casinos are large and lavish, with multiple gaming rooms spread across several floors, while others are much smaller and more intimate. A casino is usually staffed by trained personnel to supervise the gaming activities and offer advice and assistance to players.

Though some form of gambling probably predates recorded history, the casino as a place where people could find a variety of ways to gamble under one roof did not develop until the 16th century during a gambling craze in Europe. At that time, Italian aristocrats would hold private parties in places called ridotti to indulge their passion for risk-taking.

Today, casino gambling is legal in many countries around the world. Most of these casinos are operated by governments or private companies, and most have gaming tables, slot machines and other casino-style games. Some even feature a hotel and other luxurious amenities.

Most casino games have a built-in mathematical advantage for the house. This advantage, sometimes referred to as the house edge, can be very small—no more than two percent for video poker—but it adds up over the millions of bets placed in a single day by casino patrons. To offset this disadvantage, the house collects a fee from each bet, which is known as the vig or rake. This money, combined with the profits from bets placed on games that involve skill, makes a casino profitable over the long term.