In Jacks or Better the pay outs start off at a pair of jacks. The object of the game is therefore to create a poker hand stronger than a pair of jacks, hence the name; Jacks or Better.
The Decision Hand in Jacks or Better
Back in the day, video poker machines consisted of just one playing hand where you could win. Today, most machines range from four up to fifty, or sometimes even one hundred lines, or hands that you play with the same cards. You usually have one "decision hand" to which you make your decisions, the other additional hands are played just the same way as your decision hand, but the rules of probability will distribute the cards differently.
A screenshot of a 4-line Jacks or Better machine at Europa Casino. In this game, the decision hand is wagered as well as the additional hands.
Multi-hands Jacks or Better
If you ever watched high stakes poker shows on TV you might have seen how the professional players choose to play the same hand two or more times in order to decrease the fluctuation of the game. The concept is the same when you play multi-hand video poker, except that every additional hand is dealt with a new deck of cards. When poker players decides to "run a hand twice" they just let the dealer deal a new set of cards from the same deck.
Sometimes when you play video poker online there will not be any bets riding on your decision hand but sometimes there will, so check the individual game rules before you start playing.
Collect or Double Your Jacks or Better Winnings
If you want to, you have the option to try to double your winnings when you play Jacks or Better. Some sites also let you put half your money, or a ¼ of your winnings on the line in order to increase your winnings. This is done by dealing one card to the dealer and for face down cards for you to choose from. If you pick a higher card than the dealer's you double up your winnings. You can then double up again or collect your winnings.