In this update of the 1984 original, young Dre (Jayden Smith) and his mother (Taraji P. Henson) start a new life in Bejing, China, where Dre rubs the local bullies the wrong way and falls under the tutelage of maintenance man/kung-fu master Mr. Han (Jackie Chan.) Jayden Smith’s father is Will Smith (who also produced this film) and the elder Smith’s cocky confidence has obviously rubbed off, though the young Mr. Smith has not yet made it his own. Much more genuine is Jackie Chan’s grizzled, understated performance, which does more for his post-martial-arts daredevil career than dreck like The Spy Next Door. The Karate Kid is fine: Its poor qualities are tempered by its better ones.