The Winner's Curse by Marie Rutkoski
Winning what you want may cost you everything you love...
They were never meant to be together. As a general's daughter, seventeen-year-old Kestrel enjoys an extravagant and privileged life. Arin has nothing but the clothes on his back. Then Kestrel makes an impulsive decision that binds Arin to her. Though they try to fight it, they can't help but fall in love. In order to be together, they must betray their people . . . but to be loyal to their country, they must betray each other.Set in a new world, The Winner's Curse is a story of rebellion, duels, ballroom dances, wicked rumors, dirty secrets, and games where everything is at stake, and the gamble is whether you will keep your head or lose your heart.
The Winner's Curse is the first part of The Winner's Trilogy, which also includes The Winner's Crime and The Winner's Kiss (not yet released).
(Synopsis taken from amazon.com.)