A casino, also known as a gambling house, is an establishment that offers various forms of gambling. Casinos are often combined with hotels, restaurants, retail shops and other tourist attractions. In the United States, casinos are regulated by state and local laws. In some jurisdictions, casinos may be operated by Native American tribes. In addition to gambling, casinos have become known for promoting concerts and other live entertainment events.

Gambling almost certainly predates recorded history, with primitive protodice and carved six-sided dice found in archaeological sites. However, the modern casino as a place to find a variety of ways to gamble under one roof did not appear until the 16th century, during a gambling craze in Europe. Casinos generally make their money by taking a percentage of each bet, a practice known as the house edge. They may also offer a number of complimentary items to gamblers, depending on their level of play. These perks are commonly called comps.

While most patrons of a casino will not cheat or steal, some will try to take advantage of the system; this is why casinos have extensive security measures in place. For example, some have catwalks that allow surveillance personnel to watch the entire casino floor through one-way glass. In addition, many casinos have cameras in the ceiling that can be adjusted to focus on particular patrons. Often, these cameras can be monitored from a separate room where surveillance staff is located.