One of the coolest thing about Jacks or Better Double Up is the double up gamble feature in which you can guess the color of the next card. You get the opportunity to double your winnings after every winning hand. Here’s how it works: after a win, hit GAMBLE. You will go to a new screen and see five cards that are facing down. You need to choose the colour of the cards one at a time. If you guess right, your winnings double. But if you lose you will lose all the winnings and return to the main game. The bonus game will go on until you guess wrong. Of course, you don’t have to gamble your winning. You can simply collect them!