DES MOINES, Iowa – If it seems that giant lottery jackpots have people lining up at convenience stores more frequently, just wait: More big payouts could be coming.

Most attention has been on Powerball jackpots since the game’s rules were changed in early 2012 to boost payoffs. For Wednesday’s drawing, Powerball’s estimated $400 million jackpot will be the nation’s fifth-largest ever, though its jackpot hit $590 million earlier this year.

Now organizers of the country’s other big lottery, Mega Millions, are planning changes of their own.

Although Mega Millions still holds the record for the largest jackpot in U.S. history — a $656 million prize in March 2012 — organizers are hoping to more regularly see huge jackpots by lessening the odds of winning big while upping a player’s shot at smaller but still hefty prizes.

Mega Millions doesn’t plan to change its $1 ticket price, but an extra $1 option already in the game will be expanded to allow players to increase their secondary prize total to between $1 million and $5 million, a major increase from $250,000.

Game changes also include boosting the starting jackpot from $12 million to $15 million, and allowing the jackpot to grow by at least $5 million between drawings when no top winner is selected.

The changes take effect for the Oct. 22 drawing and were based on extensive consumer research, said Paula Otto, executive director for the Virginia Lottery and lead director for Mega Millions. She said officials decided not to increase ticket prices, but acknowledged Powerball’s success after it increased its ticket prizes from $1 to $2.