"Duels" is a new Flash Event recently introduced in Words With Friends. The ultimate goal of this event is to earn a total of 1000 points in order to win a mystery box.
You are matched against an opponent, and the basic premise is to play words as quickly as you can on three revolving boards striving to reach 150 points before your opponent. You are allowed to use the Pass button when you get stuck, and the Swap button is available for use as well. While the objective of Duels is to obtain 150 points ahead of your opponent, the point amount you reach will still be added to your total amount of points even if you lose a Duels game. Once you've collected 1000 points and earned a mystery box, you can continue to play Duels until the event ends.
Go to the Events section in Words With Friends to check if this event is available on your device. But hurry! The Duels Flash Event is only available for two more days.