'Hap Hak Hang' is another Jin Yong novel adaptation made in the 80's. However, I know this adaptation wasn't faithful to the novel, since one of the main characters was a rapist and his lover, a murderer, I think. Maybe because TVB didn't want to ruin the image of the main lead or because the rapist character wasn't appropriate to be portrayed on TV, but the character is changed from being a rapist to being funny and cunning.
The story stars: Tony Leung as the twins Sek Chung Yuk and Sek Fa Tin, Sheren Teng as Ding Dan. The other actresses who played these characters are unknown to me : Tit San Ho, Dong yee, Thi Giem, Bak Sau Man
Because this series is about twins, you know that Tin and Yuk will be mixed up and there will be many misunderstandings. As for the personalities of the twins, it is very typical : Yuk is cunning, smart, a fast thinker and funny ; Tin is more sentimental, naive, and innocent. You could say that one is night and the other, day.
As you can guess, the twins have been separated at birth, also a typical trait. Their parents were known as 'Black and White Swords' in the mo lam world. One time, they killed the god-son of 'Ghost', an evil character, so that on the twins' one month birthday, 'Ghost' came to avenge his god-son. The parents could only save Yuk and thought that Tin was killed because of a sword through his heart ; however, Tin's heart isn't in the same position as a normal person's is, and that saved him. Because they were afraid of 'Ghost', 'Black and White Swords' lived a discreet life and didn't teach any kung fu to Yuk. His father treated him severely while his mother spoiled him. During all those years, Tin was raised by a hunter.
In one incidence, involving Yuk's encounter with Ding Dan, his parents' identities are revealed. To protect Yuk, he was sent to 'Snow Sect' to learn kung fu. However, Yuk accidentally made the leader's granddaughter, Sau, fall off a cliff. Everyone thought she died and of course, the 'Snow Sect' followers wanted to kill Yuk to avenge her.
On the other side, baby Tin was saved and raised in the forest by the hunter. Later, the hunter dies and Tin was cheated by the leader of 'Heaven Union'. They lied about his origins and forced him to become the leader of 'Heaven Union'. Soon after, the real leader was killed. One day, Ding Dan appeared and mistaken him to be Yuk. Tin falls in love with her.
Soon, Yuk and Tin switched places. Tin was kidnapped by a highly skilled man who had a strange personality and Yuk became the leader of 'Heaven Union'. In 'Heaven Union', Yuk became close to Tin's maid, Siu Giem. However, when he learned that Boi, the skilled doctor of the 'Heaven Union', has planned for Tin to become the leader of 'Heaven union' because they wanted him to die instead of the leader, Yuk started to act wild in the hope that Boi will kick him out. He also thinks about running away.
Actually, every 18 years from 'Hap Hak Island', two men will come and invite the leaders and well-known characters from the mo lam world to follow them to the island. The invitations have been sent 2 times, and the third time is to be very soon. But what made them afraid is that those who left never came back, so people are suspicious and assumed that they are dead. If you refused the invitation, you and your sect will get killed immediately.
Boi, the doctor of the 'Heaven Union', has planned for Tin to become the leader of 'Heaven Union', so that when the two men from 'Hap Hak Island' comes, they will invite Tin and he will disappear. Yuk tries to run away, succeeds, and refuges himself in the 'Poison Sect' of San Ho, a woman that he has met. She falls in love with him. In the 'Poison Sect', Yuk encounters the most well-known rapist, Mo Yung Bak, who turns out to be a very sympathetic guy and will become a close friend. At the same time, he re-encounters a girl named Dong Yee, who he fell in love with when he was still in the 'Snow Sect'.
Dong Yee's family was also well-known in the mo lam world. However, while she was away with her grandma, mother, and other women of the family, 'Ghost' came and killed all the remaining members at home. When, they came back, they found all the bodies. Dong yee's mother committed suicide next to her husband while the grandmother swore vengeance. However, they aren't skilled enough to confront 'Ghost' yet, so have to hide themselves in a valley for more than 10 years. Now, capable of defeating 'Ghost', they exited the valley and kidnap Mo Yung Bak, a good friend of 'Ghost', to threaten him. However, they failed because of Yuk. Later, Dong yee and her family are separated, so she follows Yuk. Yuk loves her very much and this caused San Ho to become jealous. Because of this, San Ho makes Yuk drink a poison that even she herself can't cure. Misunderstandings after misunderstandings occur, and finally Yuk has the pleasure to live with San Ho, Dong Yee, Ding Dan and Siu Giem. At first they argued, but for him, because they all loved Yuk sincerely, they agreed to be good friends.