In a casino, customers gamble by playing a variety of games of skill and chance. Most casino games are rigged with mathematically determined odds to give the casino an advantage, called the house edge (also known as the rake). Comps or complimentary items are also available, and the payout percentage is usually based on the number of bets placed and the amount of time players spend in the casino. For this reason, casinos have a tendency to keep a high house edge.

The United States currently has over a thousand casinos, and the number continues to grow. Although Las Vegas and Atlantic City are the two largest cities for the number of casinos, the majority of US states have legalized some type of casino. The Las Vegas Valley is home to the largest concentration, and other cities such as the New York metro area and the Chicago region are known for their renowned casinos. Although casinos have been around for many years, they are often not the focal point of a community.

Many casinos concentrate their investments on high rollers. These players typically spend more money than the average casino patron and play in separate rooms from the main casino floor. These gamblers typically bet large amounts of money, and they typically spend several tens of thousands of dollars. Because these gamblers make the casino a significant amount of money, they are often rewarded with lavish personal attention and free drinks. While most casinos are designed for casual gamblers, the atmosphere in a casino is more intense and is often based around high rollers and the types of games they play.