Gambling in some form has been a part of human culture throughout history, with primitive protodice and carved six-sided dice found in archaeological sites. But the casino as a place to find a variety of gambling games under one roof did not develop until the 16th century, when a gambling craze swept Europe and Italian aristocrats created private gambling houses called ridotti. While technically illegal, these places were rarely bothered by legal authorities.

Casinos are businesses, and like any business they must earn a profit to stay in operation. To ensure this, every game offered by a casino has built-in advantages that give it a mathematical expectancy of winning. This assures the casino that it will always win more money than it loses, even if only for a single day.

To maximize their profits, casinos offer free entertainment and other amenities to large bettors. These freebies are called comps and include free hotel rooms, dinners, tickets to shows or limo service. They are given to players who meet certain spending criteria set by each casino, and are generally only available to high-spending players.

During the 1950s, organized crime figures began investing in casinos in Nevada, helping them expand and improve their image. Legitimate businessmen were hesitant to get involved in such ventures, which carried the taint of “vice.” But mobsters had no problem with casinos, which provided lucrative funds for their drug dealing, extortion, and other racketeering activities. They took sole or partial ownership of some casinos, and influenced the results of games by threatening casino employees. This skewed the fairness of the gaming operations and reduced the profits they generated.