The film's protagonist is Jason Tripitikas (Michael Angarano). He's a kung fu-obsessed teen from Boston whose life revolves around watching old movies found in a Chinatown shop run by an ancient pawnbroker.

Jason spies a fighting staff in the pawnshop's back room, and before he knows what hit him, he is hurled back in time to China. His task is to deliver the staff to its rightful owner, the playful Monkey King, who has been encased in stone for the last 500 years while the Jade War Lord (Collin Chou) has been making life miserable for everyone in the vicinity.

No quest is complete without sidekicks, and Jason has some of the best, including Lu Yan (Chan), the master of drunken kung fu; a somber monk (Li); and Golden Sparrow (Liu Yifei), a young woman hell-bent on revenge. Playing for Team Evil are the warlord and Ni Chang, the White-Haired Demoness (Li Bing Bing).

The film's fight choreographer is the accomplished Woo-Ping Yuen ("The Matrix"), making "Forbidden Kingdom's" fights of interest, especially the long-awaited Chan and Li face-off.