A casino is a gambling establishment where people can play games of chance. There are some games that involve skill, but most are pure luck. The house has an advantage over the customers, which is referred to as the “house edge.” The house also takes a fee or commission on some of the bets placed by players called the rake. Casinos sometimes offer free items to gamblers, known as comps.

Gambling is only a small part of the appeal at many casinos today. Restaurants, bars, shops, spas and entertainment venues are usually attached to the gaming facilities. Many of these are run by investment banks, which are becoming increasingly involved in the business as a way to diversify their earnings.

In the past, some of the largest casinos in the world were built in cities that were not considered to be gambling destinations. For example, the elegant spa town of Baden-Baden was a playground for Europe’s wealthy aristocrats 150 years ago, but nowadays it attracts gamblers from all over the world to its red-and-gold poker rooms and glamorous slots machines.

Despite their size and splendor, modern casinos are not immune from fraud and criminal activity. The rules that govern each game, the location of betting spots on a table and the expected reactions and movements of players all follow predictable patterns, making it easy for security staff to spot suspicious behavior. In addition, elaborate surveillance systems give the casino an eye-in-the-sky view of every table and window from a room filled with banks of security monitors.