The lottery is a lot of things to a lot of people: a way to dream big, a source of entertainment, or even an opportunity to win money. But for many of those who play, it’s also a disguised tax that hits low-income households hardest. That’s because the chances of winning are so low that those tickets can add up to a sizable budget drain.

It’s no surprise that so many people fall prey to the illusion that they can increase their odds by playing more often or by buying larger numbers of tickets. It’s just a simple rule of probability: you don’t multiply your chances of winning by playing more frequently or betting more money on each ticket. Each ticket has its own independent probability, regardless of how you buy them.

Lottery tickets are expensive, and for most people that expense is not deductible. That’s why it is important to understand how lottery odds work and what you can do to make smarter financial decisions. Whether you’re considering entering a lottery or just want to learn more about the odds of winning, NerdWallet is here to help.

As early as the 15th century, various towns held public lotteries to raise money for town fortifications and poor relief. By the 1960s, state governments, looking for ways to expand their social safety nets without enraging an increasingly anti-tax electorate, began to turn to the lottery for revenue.

It was not a particularly wise move. While a portion of lottery proceeds does go toward education, the overall effect is to shift taxes away from the middle class and working class in favor of the wealthy. And because lottery revenues aren’t as transparent as income or sales taxes, they don’t get the same voter approval.

In order to keep ticket sales up, states must pay out a respectable percentage of the winnings. That reduces the amount available for state programs like education, which is the ostensible reason for having a lottery in the first place.

In addition, retail outlets that sell lottery tickets collect commissions on their sales. So, in addition to paying out prize money and covering operating and advertising costs, state lotteries can become a disguised tax on those who play them. And because people with lower incomes are more likely to play, critics say that it’s a tax on those who can least afford it. Despite these arguments, the popularity of lotteries continues to grow, with players spending billions each year. That’s partly because of the enduring human desire to dream big. But for some, the lure of a huge jackpot is enough to overcome the math. And if you’re not careful, you might find yourself falling into the same trap as them. It’s time to start thinking differently about lotteries. After all, there are better ways to spend your money than on a slim chance of winning millions.