Every big lottery headline starts the same way: a jackpot nobody won last time, now bigger than ever. The mechanism behind that growth is simple, even if the numbers get dramatic.
What is a rollover?
Lotteries set aside a portion of ticket sales for the top prize pool. If nobody matches all the required numbers in a draw, that money doesn't disappear — it "rolls over" and is added to the pool for the next draw. Combined with a fresh round of ticket sales, the jackpot on offer keeps climbing until someone finally wins it.
Why jackpots grow faster near the top
As a jackpot gets bigger, it tends to attract more media attention and more players — and more ticket sales mean an even larger prize pool for the next rollover if it isn't won. This is why jackpots often seem to accelerate in the final weeks before someone hits the numbers: a $50 million jackpot might climb by a few million per draw, while a $500 million jackpot can jump by tens of millions in a single rollover simply because so many more tickets are in play.
Do all lotteries roll over the same way?
Not exactly. Some lotteries cap how many times a jackpot can roll over before a mandatory "must be won" draw, where the prize is shared among the next tier of winners if nobody matches every number. Others roll over indefinitely. The odds of matching every number stay exactly the same from draw to draw — a bigger jackpot never means better odds, only a bigger prize if you win.
Bigger jackpot, same odds
It's worth remembering that the odds printed on a lottery's official rules don't change because the jackpot has rolled over five times. What changes is only the size of the prize being offered for those same odds. Check the current results page for any lottery tracked on this site to see whether its jackpot has rolled over and what the next draw is offering.