About 51 million people—a quarter of all Americans over 21—visited a casino in 2002. They can choose from a variety of locales, from the glitzy strip in Las Vegas to illegal pai gow parlors in New York City’s Chinatown. Shuttle buses crammed with tourists run 24 hours a day at destinations like Atlantic City, and direct flights to casinos are available from airports around the world.

In casinos, the games are designed with built-in advantages for the house. These gains may be small, lower than two percent, but they add up over the millions of bets placed each year by gamblers. In addition, the casino charges a fee for every bet that is placed. The percentage of the total bet that the casino collects, known as the “vig” or “rake,” can vary depending on the game and the rules.

Casinos often reward high-volume players with free hotel rooms, meals and show tickets. They may also give limo service and airline tickets to frequent visitors. These “comps” are a significant source of revenue for casinos and can offset losses from other gambling products.

Mobster money flowed into casinos in the 1950s, and mafia members became personally involved, taking sole or partial ownership of some of them. They influenced the outcomes of certain games and even threatened casino personnel. Today, casinos promote responsible gambling by providing information and contact details for organizations that offer specialized support. Some states include statutory funding for these organizations as part of the conditions of casino licensing.