When the word casino is used, people generally think of one of the Las Vegas megaresorts, but casinos are also found in smaller towns and cities. They are characterized by flashing lights, games of chance and a general atmosphere that encourages gambling. The glitz and glamour of the casinos can also attract criminal elements, who may participate in illegal activities such as drug dealing or extortion.

In 2008, 24% of Americans reported visiting a casino, compared to 20% in 1989. The casino industry has become a major source of revenue, bringing in millions of visitors every year. Many casinos offer a wide variety of gambling opportunities, including slots, table games, bingo, and poker. Unlike other forms of gambling, which involve skill, most casino games have mathematically determined odds that ensure the house always has a slight advantage over players. This advantage is known as the house edge or expected value.

Casinos are businesses that aim to maximize profits by attracting large numbers of customers and encouraging them to spend more money than they initially intended. This is accomplished by offering perks such as free food and drinks, cheap rooms and show tickets, and other incentives to gamblers. These perks are called comps, or complimentary items.

Some casinos focus on attracting high-stakes gamblers, who can bet tens of thousands of dollars or more. These people are known as high rollers. They are offered free rooms, shows, and other amenities in addition to reduced-fare transportation and limo service.