A casino is an establishment for certain types of gambling. The modern casino is like an indoor amusement park for adults, and the vast majority of the entertainment (and profits for the owner) comes from games of chance. Slot machines, blackjack, roulette, craps and keno provide the billions in profit that casinos rake in each year.

Gambling almost certainly predates recorded history, with primitive protodice and carved six-sided dice found in ancient archaeological sites [Source: Schwartz]. But the concept of a casino as a place to find many different ways to gamble under one roof did not develop until the 16th century. At that time, wealthy Italian aristocrats held private gambling parties in their houses, known as ridotti, which functioned as public casinos despite being illegal at the time.

Casinos make money by charging a percentage of every bet to players who win. This can be a small amount, less than two percent, but it adds up over millions of bets. Casinos also earn revenue by giving free goods and services to “good” customers. The perks are called comps, and can include free hotel rooms, meals, show tickets, limousine service or airline tickets.

Casinos draw in local residents and tourists from around the world. But critics say they shift spending away from other entertainment options, cause people to become addicted to gambling and lower local property values. The industry also generates billions in profits each year for private investors, casino operators and Native American tribes. But casino owners must also deal with the problem of compulsive gamblers, who can ruin families and destroy careers.