Appledog wrote: Usually you will be steered away by hook or by crook from the intention of killing someone. I.E. you are not taught those techniques and if you persist you are kicked out of the school. There are exceptions but generally it looks bad for the teacher when the student ends up killing someone.
Just an anecdotal story that speaks to John's question ....
There is an action in several of Feng Ziqiang's forms. One of the possible applications of the action is a screwing back-fist to strike the opponent's temple with the extended knuckles of the fist. My teacher told me of two examples of its use. One example involved a student of his to whom he taught that application. The student went on to fight in Russia in ring fights. The student used that on an opponent in the ring. The opponent died as a result of the strike. The student was charged with murder, found guilty and was executed.
In the other story, my teacher was challenged. He knocked the challenger out with the same single strike to the temple.
I once asked my teacher, who had some reputation as a street fighter in China, about competing in MMA fights. He said the only way he would win is if he maimed the opponent, techniques that aren't allowed, for obvious reasons.
No, I haven't killed or maimed anyone.
I had my wrist broken once, but I don't think that counts.
I agree with Steve that Taijiquan is just another martial art with no unique killing moves.