Is this based on a video game? If so, it's far better than any Uwe Bolle adaptation.
Dastan (Jake Gyllenhaal) is the adopted son of the King. He had been a street urchin and a thief as a child. Years later, he's caught up in a conspiracy. His father is killed he's framed for it. Now a fugitive, he has to prove his innocence and uncover who the true villain is. He also feels somewhat guilty about leading the invasion force on Princess Tamina's (Gemma Arterton of CLASH OF THE TITANS) kingdom--and ends up protecting her. Oh, there's also vial of magical sand that can reverse time, which comes in handy, especially at the end of the movie.
Although I still equate Gyllenhaal with BUBBLE BOY, he does a decent enough job as the adventurous character. If you enjoy movies like 300, CONAN or TV series like ROME you'll definitely like this amalgamation.