A casino is a building where people gamble and play games of chance. Its patrons are a diverse bunch, from regulars who strut with confidence expecting to win big to those who’re trying to make back the money they lost on their last trip. Regardless of their reasons for being in the casino, they all share one thing – they have fun. With music blaring and coins clinking, it’s hard to resist the rush of adrenaline.

But what’s really going on inside the casino is something much more sophisticated than the glitzy facade suggests. Like any successful business, a casino has a strategy that ensures it’s always winning. Its house edge is designed to prevent its customers from leaving with anything more than the house’s winnings.

With this in mind, it’s no wonder that casinos spend a lot of time and money on security. Security starts with dealers, who watch their tables closely and can quickly spot blatant cheating such as palming or marking cards or dice. Similarly, pit bosses and table managers have a bigger picture view of their tables and can catch betting patterns that might indicate cheating.

But it’s not just the gambling and games of chance that makes casinos so profitable, it’s also the hotel rooms, bars, restaurants, gyms, spas, and even art galleries and museums. So to find the best casino in the world, we use a methodology that looks at 40 casinos around the globe, scoring them on their prices of entry, hotel and onsite dining, gyms and spas, city safety, airport accessibility, reviews, and casino space size.