A casino is a place where people can play a variety of games of chance, and the main source of money for most casinos comes from gambling. Slot machines and table games such as blackjack, baccarat and poker earn the most money for casinos, which also make money from ticketed events, restaurants and other amenities. A casino can be as large as a resort or as small as a card room, and it may be found in places such as Las Vegas, Atlantic City, Macau in China and other major cities, as well as on riverboats, barges and at racetracks converted into racinos.

While gambling likely predates recorded history, the modern casino as a venue that brings together a wide range of gambling activities under one roof first developed in the 16th century during a betting craze that swept Europe. In those days, Italian aristocrats would hold private parties at their homes known as ridotti to gamble and socialize with friends.

Modern casinos offer a variety of amenities to attract customers and keep them gambling. Comps (free goods and services) are offered to high-volume players, who are often given free hotel rooms, meals, show tickets and even limo service and airline tickets. Elaborate surveillance systems use cameras that watch every table, window and doorway to monitor activity; these systems can be adjusted by security workers in a control room to focus on suspicious patrons. In addition to these technological tools, the vigilance of casino staff is essential for maintaining a safe gambling environment.