A casino, or gambling house, is a building or room where people can play various games of chance. The games usually involve skill, but some also have an element of luck. The house always has an advantage over the players, and this is known as the house edge. Casinos are most often found in cities with large populations of people who are interested in gambling, such as Las Vegas, Nevada and Atlantic City, New Jersey.

Although gambling predates recorded history, the modern casino did not develop until the 16th century. This was during a period when a gambling craze swept Europe. During this time, Italian aristocrats held private parties in places called ridotti (small clubs) where they gambled. Unlike large public casinos, ridotti rarely got bothered by the police.

The modern casino has many amenities to attract customers, such as free drinks and stage shows. The games are usually supervised by a team of employees called pit bosses, who are responsible for the integrity of the game. Casinos also have surveillance systems that monitor activity in and around the casino. Some have catwalks that allow surveillance personnel to look directly down, through one-way glass, on the activities at the tables and slot machines.

The security of a casino is important because of the large amounts of money that change hands within its walls. Patrons and staff may be tempted to cheat or steal, either in collusion with each other or on their own. To combat this, casinos have security measures in place, such as surveillance cameras and a strong code of ethics for their employees.