General Mills is giving away 15,000 boxes of Marshmallow Only Lucky Charms

St. Patrick's Day may be over, but General Mills is still giving fans a sweet pot of gold: Limited-edition Lucky Charms Marshmallow Only cereal. But, they're not at the end of a rainbow — cereal lovers have to be lucky enough to win.

A press release published Monday announced that 15,000 boxes of the beloved treat are up for grabs during the giveaway. While the company has offered the "Marshmallow Only" cereal promotion twice before, more boxes than ever are available for lads and lassies to snap up this time around. 

The brand first unveiled the promotion in 2015, giving 10 people the chance to win their own box of the rare variety, and again in 2017, expanding to a 10,000 box giveaway. After what the company calls "overwhelming success and enthusiasm following the first two campaigns," the cereal is back again. This time, there's a twist: Boxes will be filled with rainbow and unicorn marshmallows.

"It's no secret that Lucky Charms fans love the marshmallows," said Scott Baldwin, director of marketing for Cereal at General Mills. "Consumers have flooded our inboxes and swept our social feeds begging for Lucky Charms Marshmallow Only to return. You asked, and we listened!"

Feeling lucky? Here's how to win your very own box of the cereal

1.  Look for specially-marked Lucky Charms boxes at retail stores in the U.S. from now through the summer.

2.  Enter the code discovered on the panel inside the cereal box at MarshmallowOnly.com to see if you've found a pot of gold.

3. Winners will have a special box of Lucky Charms Marshmallow Only shipped straight to their home.

Winners of the Marshmallow Only boxes will also be allowed into the "elite" Lucky Charms Marshmallow Only club, according to the release.