Every 10 years, the Wu Dang and Invincible Clan chiefs have a duel, and the past two times the Invincible Clan has won. The Wu Dang chief has been training hard for 10 years, but still isn't sure his skills are strong enough to win. His own master has retired for 20 years to study the Silkworm Technique, Wu Dang's greatest kung fu, but has been unable to reach the final stage.
Norman Chu plays the BASTARD SWORDSMAN, a servant at Wu Dang clan who is picked on and bullied by the students and given rough justice by the masters. Everyone calls him bastard because he doesn't know who his parents were (using the traditional sense of the word rather than the British slang), and nobody will teach him kung fu... except a mysterious masked stranger who appears at night and has secretly been passing on some skills.
Then bunch of other stuff happens that there's really no need to explain - it's a fairly typical wu xia story in the same vein as Heaven Sword and Dragon Sabre.
BASTARD SWORDSMAN is another of those fantasy wu xia that appeared in the early 80's, utilising heavy amounts of wirework and crude special effects to represent the kind of supernatural abilities that fighters were meant to be able to achieve in the wilder wu xia fiction. Director Tony Liu was one of the pioneers of this style, along with Ching Siu-Tung. Liu has help with the action direction from Yuen Tak, one of the best people for implementing crazy wire-based action. BASTARD SWORDSMAN features more of the wild and wacky action choreography that had previously been seen in Holy Flame Of The Martial World, Zu: Warriors Of The Magic Mountain etc. There's some imaginative duels choreographed and filmed well.
There's also a good story, rife with the typical exaggeration and melodrama that makes a good wu xia pian. Don't expect the greatest acting or the highest production values, or a lot of depth and profundity... but do expect an enjoyable popcorn flick :)