A casino is a gambling establishment where people can place bets on various games of chance for money or other prizes. Most casinos feature a variety of gambling games, such as blackjack, roulette, craps and slot machines. Some also have dining and entertainment venues. Some casinos are located in large resorts, while others are standalone facilities. Some states have legalized casino gambling, while others have banned it.
In the United States, there are more than 3,000 casinos. Some casinos are owned by Native American tribes, while others are operated by state governments or private companies. Regardless of ownership, the vast majority of casinos are located in states where gambling is legal. Some are located in cities with a high population of people who enjoy gambling, while others are located in rural areas with few other tourist attractions.
Casinos earn billions of dollars in profits each year. Though musical shows, lighted fountains and shopping centers help draw in customers, the vast majority of a casino’s revenue is made from gambling. While many people think of casinos as huge, glass-and-steel temples of overindulgence, there are a number of casinos that are small and cozy.
Although gambling likely predates recorded history, the modern casino as a place to find a variety of ways to gamble under one roof didn’t appear until the 16th century, when a gambling craze swept Europe. Italian aristocrats would hold parties called ridotti, where they could play all sorts of games without worrying about the police. 
The first American casinos appeared in Atlantic City in 1978, and in the 1980s, they began popping up on Indian reservations, which were not subject to state antigambling laws. From the 1990s on, a steady stream of new casinos has opened, both in traditional land-based locations and on riverboats and cruise ships. Some casinos have a mix of gambling and non-gambling activities, while others are focused solely on the games of chance.
Casinos make money by charging a small percentage of every bet to the house. This is known as the vig or the rake, and it gives the casino a mathematical advantage over the players. It is very rare for a player to win more than the casino’s vig, but the edge is enough to keep it in business.
Most casinos have a variety of security measures in place to prevent cheating and other types of crime. Most of these involve cameras and other surveillance equipment, but some are more subtle. Dealers are heavily trained to watch for blatant cheating like palming or marking cards and dice, and table managers have a much broader view of the tables than the players themselves. Casinos also have catwalks over the gaming floor, which allow security personnel to look down through one-way glass at the action. This way, they can monitor the behavior of the players without disturbing them or being seen themselves. Those who spend a lot of time playing or betting are often given free drinks, food and even hotel rooms and limo service in return for their loyalty.