The Invincible Armour

Invincible Armor is a 1977 Hong Kong-Taiwanese kung fu film starring Hwang Jang-lee, John Liu, and Tino Wong.

Plot
On patrol through town, Ming General Chow (Liu) observes a fighter, Hu Lung, fending off a group of bandits. Impressed by the fighter's skills, General Chow arranges for Hu Lung to meet the Minister of Royal Security as a potential candidate for joining the Ming forces. While sparring in the courtyard to test his skills, Hu Lung produces a knife and assassinates the Minister before leaping over the courtyard wall and escaping. As General Chow rushes to the Minister's aid, the guards arrive and immediately arrest Chow for the murder. En route to the court, a group of soldiers arrives with orders to kill Chow, who defeats the group and escapes.

Ming Minister of State Cheng (Lee), an authoritarian ruler and master of the Eagle Claw and Iron Armor techniques, summons his most skilled enforcer, Shen Yu (Wong), to hunt down Chow and arrest him. Chow hunts for Hu Lung, but must avoid the authorities along the way who are attempting to kill him. He eventually finds Hu Lung, but is thwarted by Shen Yu as Hu runs away. Chow informs Shen Yu that he has been wrongly accused and that Hu Lung is the actual murderer, but Shen is not convinced and he fights with Chow. The fight is interrupted by an old man claiming to also be after General Chow, and fights with Shen over who will get to bring him in. Chow uses this opportunity to escape and continues his pursuit of Hu Lung.

The old man is later revealed to be Hu Lung's old teacher, who previously expelled Hu from their clan. Hu confesses to his old teacher that he was paid by Minister Cheng, a former classmate of the old man, to carry out the assassination. The old man confronts the Minister over his actions and sets a trap to kill him, but is killed by Cheng in their ensuing fight.

Meanwhile, Chow learns the Iron Finger technique from the old man's grandson and granddaughter to defeat Cheng's Iron Armor, but his training is cut short when Shen Yu and a 2nd enforcer sent by the Minister arrive to arrest him again. After the 2nd enforcer attempts to kill Chow over Shen's objections but fails, Shen begins to doubt Chow's guilt and gives him three days to locate Hu Lung and clear his name. Before he can catch up with Hu Lung, Hu is killed by Cheng, however Shen discovers evidence on Hu's body that the minister is involved. That night, when staying at an inn nearby, multiple assassins attack Shen Yu, but he is saved by an unknown individual who also delivers him a strange letter. The next morning, he confronts the minister and tells him that he's fully aware of his activities, in which case the minister sends his henchmen to engage him.

With Minister Cheng's plot exposed and his henchman defeated, he offers Shen Yu to join him, which Shen Yu outright refuses. With no other choice left, he attacks Shen Yu, who is soon assisted by Chow and the old man's two grandchildren. During the fight, Chow discovers that Cheng's weak spot is his testicles and that Cheng is able to retract them into his body for protection. Through the group's combined efforts, Chow is able to use his Iron Finger technique to cause Cheng to drop his testicles so Chow and crush them, killing Cheng.

Cast

 * Hwang Jang-lee – Minister Cheng
 * John Liu – Chow Lung Fu
 * Lee Hoi-sang – Hu Lung
 * Tino Wong – Shen Yu
 * Phillip Ko – Hu's teacher
 * Yuen Biao
 * Corey Yuen

Reception
Review aggregator site Rotten Tomatoes gives the film a score of 82% based on 321 user reviews.