In addition to offering a variety of games, each lottery also has a policy for awarding prizes. Some use a percentage of ticket sales as the prize fund; others offer fixed amounts of cash or goods. A common format for lotteries, as used in the United States, is a single fixed-sum prize. In some cases, the organizers of a lottery take on a certain amount of risk, requiring them to pay out winning tickets even if ticket sales fall short of a given amount.

For example, if ticket sales for an instant game were low, the operator might reduce the prize level or increase the odds of winning by making it harder to win the top prize. This strategy, along with aggressive marketing and ad campaigns, has made some state-sponsored lotteries the dominant sources of gambling in their jurisdictions.

There’s nothing about this approach that makes it any more morally sound than the strategies of cigarette companies or video-game makers. What’s more, no one is above using the psychology of addiction in order to keep people playing.

The era of big jackpots is not over, though. Super-sized prizes drive lottery sales, and they’re a good way to get free publicity on news sites and TV. But there’s a limit to how much money can be won in one drawing, and the longer it takes to hit a large sum, the more likely the jackpot will roll over to the next drawing.