Before Chang's movie, sword-fighting films featured theatrical action choreography that drew heavily on Peking opera. Chang introduced direct and brutal elements into the fighting scenes that bordered on the sadistic.

This resulted in a more modern feel which not only set the template for the director's own prolific body of work - he rarely strayed from it over the course of about 100 movies - but also just about any Hong Kong martial arts film that came after it.

is often described as a revenge drama, but this is only partly true as the psychology of its hero is far more complex.

The hammy arch-villain aside, it's more of a fully fledged drama: the titular swordsman wishes for a quiet life, but is forced to fight because he has to.

When his paramour asks him to stop training and become a farmer, the swordsman says he must continue so he can protect her from thugs roaming the countryside. And when the fighting is done, he does indeed become a farmer.

The story is unusual. Fang (Wang) is the son of a servant who dies protecting the master of a sword-fighting school. In return for his father's sacrifice, the master brings Fang up as one of his students. Fang is teased by the other students, and the master's spiteful daughter cuts off his sword-fighting arm during a confrontation.

Fang flees to the countryside and falls in love with a kindly farm girl. Realising he has to fight to protect her, he learns to wield a sword with his left hand.

When Fang discovers that Long-Armed Devil, the man who murdered his father, has developed a secret weapon to kill his master - a vice-like sword grip - the swordsman realises his left-handed technique can help him to save his former protector.

is Chang's most famous work, but not his most typical. As his career progressed, he dispensed with detailed characterisation and plotting to focus on portraying male aggression.

The sadism and masochism that surfaced in later became the sole focus of Chang's films, expressed in graphic and bloody fight scenes.