What does Double Up mean?

Answer 1

After you win, you can play a special "double or nothing" game called "double up".

You typically choose "High" or "Low". If the dealer draws 2-7, low wins, 8 is a "push" and you get your bet back, and for 9-Ace, high wins. If you win, you get double of your original winnings, and you can play "double up" again, if you lose, you get nothing.

"Double up" is one of the rare casino bets you can make with no house edge.

Double up in slots is a feature of certain video Poker slot in which you can double your winnings. You have a choice of four or five unseen cards you can pick from, if your card is higher than the dealer's card you win, if it's lower you lose. You can keep on doubling up as long as you keep winning.