A gambler won $1 million Sunday on a $20 poker bet at an Atlantic City casino.

Harrah's Resort Atlantic City announced that a woman it did not identify hit the jackpot at 12:30 a.m. in a promotion called "Three Card Poker 6 Card Bonus."

The promotion offers gamblers various cash prizes if they draw a royal flush. The payouts they receive depend on the amount they bet and whether the royal flush is in diamonds, hearts, spades, or clubs.