A lottery is an organized scheme for awarding prizes based on chance. It’s an ancient practice—drawing lots for everything from property to slaves has been documented in many ancient documents—and the lottery became a popular way to raise funds for towns, wars, colleges and public-works projects in the seventeenth and eighteenth centuries. Today, dozens of countries and territories have national or state lotteries that raise billions in revenue each year. Some critics call them a disguised tax on people who can least afford to play.

Despite the popularity of the lottery, most people don’t understand how it works. The odds of winning are extremely slim, but the lure of a big jackpot keeps millions of people playing. And while winning a lottery jackpot can help some people, for others it’s just another form of gambling that can leave them worse off than before.

If you want to win the lottery, try choosing numbers from different groups or clusters and avoid those that end with the same digit. Also, don’t base your selections on a pattern, as that’s one of the biggest mistakes you can make when picking numbers.

You’ll also need to budget for taxes if you win. Depending on your state’s tax laws, you might owe as much as 37 percent of your winnings. That means if you won the $10 million jackpot in our example, your check would be only about $5 million after federal and state taxes.

While some states have banned lotteries, most use them to raise money for state projects. They are also popular with private organizations that want to fund special events or community projects. State lotteries are a relatively easy and inexpensive method for raising funds. And they can be a good source of income for small businesses that sell the tickets. Lottery companies often team up with sports franchises and other large companies to provide popular products as prizes in their games.

Proponents of the lottery argue that it’s a cheap and safe form of entertainment that gives people an opportunity to fantasize about becoming rich. They also point out that the lottery has boosted state economies by providing a way to enhance budgets without raising taxes. And they point to studies that show that lottery participation is higher among low-income individuals.

But the truth is that most lottery winners don’t win the big jackpots or even break even on their purchases. And some of those who do win find themselves in a downward spiral that can affect their families, jobs and communities. And for those who don’t win, they’re left with a nagging feeling that they should have. For these reasons, it’s best to treat the lottery as a form of entertainment and not a way to get out of debt. This article was written by NerdWallet contributor Michael Chartier.