There are lot of adaptions on wuxia novels in both movies, TV series and of course comics. Basically, what I've seen are...
1) Those that storyline is COMPLETELY different from the novel. The only thing that is the same are the characters.
2) Those that stay on the main plot of the original novel (as in all "important events" still happen), but with a lot of other "extras" added in.
3) Those that basically follows the novel, but usually add in an "ultimate boss" at the end for the big fight that everyone's waiting for.
4) Everything should follow the original.
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Examples I've seen....
Type 1: I can think of the "Jue Dai Shuang Jiao" (act by Andy Lau) movie. They have crap like Yan Nan Tian is Yao Yue husband, Hua Wu Que falls in Xiao Yu Er...all those crap. I hate these...
Type 2: Recall some people in the forum mention the Snowy Fox 99 where MRL gets raped and all the stuff...
Type 3: Singapore Xiao Ao Jiang Hu basically follows the whole plot, but at the end, Dong Fang Bubai is "REVIVED" from death and became a super demon. Another one is the Tian Long Ba Bu comics I've read, where at the end, Murong Fu mastered the "Bei Ming Shen Gong" and suck up the Sweeper Monk internal strength and became super godly. Final fight was 3 main characters ganging up on him. But the ending is still the same. He still goes mad, and Xiao Feng still suicides.
Type 4: Hmm...I've collected Li Zhi Qing "Legend of Condor Herose" comics that basically follow the novel totally.
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So what type do you prefer and which one is your favourite? Basically, I think Type 3 can be very good if done well. The "expanded fight scenes" are sometimes really cool to watch and it adds the "extra spice" that is missing in the original novel. For example, who wouldn't want to see YG duel with GJ at the end of ROCH (just for the fun). That could be added in without hurting the story.
Of course, SWORD GOD Zhuo Bu Fan fans would probably love type 1 where they make Zhuo Bu Fan reach the PEAK OF PERFECTION and kill everyone he sees.