A casino is a place where people gamble money in exchange for chips that can be redeemed for cash or other items. It also includes games of chance and skill, such as baccarat and blackjack. Casinos usually feature multiple gaming tables and slot machines. Some casinos are open to the public, while others require membership or a guest pass to enter.
Gambling probably predates recorded history, with primitive protodice and carved knuckle bones being found in some archaeological sites [Source: Schwartz]. But the modern casino as a gathering place for a variety of gambling activities did not develop until the 16th century, when a gambling craze swept Europe. European aristocrats would throw parties in private rooms called ridotti, where they could try their luck at dice and other games.
The modern casino is often associated with organized crime, owing to its seamy image and the fact that it is legal in only a few states. Mob money funded the expansion of casinos in Reno and Las Vegas, and gangsters took sole or partial ownership of many of them. However, federal crackdowns and the prospect of losing a casino license at even the whiff of Mafia involvement eventually drove the mob away from the business.
Most casinos have elaborate security measures. Floor managers and security personnel watch over the games to spot cheating or robbery. Some casinos have catwalks in the ceiling that allow surveillance personnel to look directly down, through one-way glass, on the table games and slot machines. Observers can see how much money a machine or game is making and whether the players are winning or losing. Casinos have mathematicians that study the house edge and variance of their games to help them plan for profit.