Lottery is a game in which numbers are drawn for a prize. It’s a form of gambling that has gained widespread popularity, with state-sponsored lotteries in all 50 states. But it has a dark side, as Vox reports. Studies have found that lottery tickets are bought disproportionately in poor neighborhoods, and that the winners are often low-income or minorities. And while lottery revenues help state budgets, those funds are largely derived from just a few percent of players.

The concept of drawing lots to make decisions or determine fates has a long history—with multiple instances mentioned in the Bible, for instance. But lotteries as a way to get material goods have been around even longer. They were common in colonial America, where they played a major role in financing public works projects. The foundations of Harvard and Yale, for example, were paid for with lottery money, and George Washington held a lottery to raise money to build his road across the Blue Ridge Mountains.

But despite the many successes, winning the lottery is not easy. As the HuffPost Highline explains, it takes a lot of time and energy. It also requires a strategy to maximize your chances of winning. For instance, a couple in Michigan figured out how to increase their odds by buying large groups of tickets—several thousand at a time—that cover every possible combination of numbers. They ended up with nearly $27 million over nine years. But even the most devoted lottery players can run into trouble.