For karate people, "vital points" refers to targets in the human body that are especially vulnerable to karate blows. The goals of karate are to break bones or produce a knock-out, which makes the karate list of vital points rather short. Karate fighters can apply a lot more force than other artists can, so the discussion tends to focus on which parts of the cranium can be breached by a knuckle and which cannot. If you can break a stack of boards with your hand or foot, you should study karate vital points for a very important reason: you could kill someone by accident. You need to know the vital points in order to avoid them.
In the grappling arts, especially jujutsu and aikido, the "vital points" are usually nerves and soft-tissue points where pressure produces paralyzing pain. There are dozens of such points on the human body, and it is possible that you can jam a thumb into your opponent just about anywhere and get this effect if you are strong enough. Any pressure point that makes the opponent flinch (breaking his posture) is good enough for most jujutsu applications. Some of the jujutsu vital points are so painful that you can use them to enforce compliance.
The two paragraphs above describe the practical side of vital point theory. From this point on we enter the bunkum side.
It is not easy to write down the location of a vital point on the body. You can put your finger on the exact spot, but you can't easily identify that one square inch for your reader. As a result, experts turn to existing systems of human anatomy to provide names and locations. I used Gray's Anatomy to identify things like "the superior wing of the sphenoid bone," so people would know exactly what I was talking about.
Other writers have turned to the Chinese acupuncture meridian system, using named locations on the qi meridians to identify the locations of vital points. This is an inferior approach because it limits you to just the points on the meridians, when in fact the vital points are all over the body. If the meridians are the only anatomical system you know, however, then you are going to write in those terms.
The "bunkum" arises as a side-effect of using the qi meridians to identify the location of vital points. The qi theory of health is based on magical thinking, and has no anatomical, physiological, or histological basis. Whenever we start to talk about locations along qi meridians, magical thinking creeps in.
You don't have to look far to find books that enshrine this kind of thinking. There is a spot on the arm where a sharp blow weakens and stuns the hand. This technique really works and should be studied. The location is identified as a qi point, and that qi point supposedly influences the health of the bowel. Therefore, goes the magical theory, striking this point on the arm will upset the opponent's bowels. This is especially true at 4 a.m., the books say, because that's when the vital point is the most active!
If you want to upset someone's bowels, you kick him in the bowels. You don't wake him up at 4 a.m. and tap him on the arm. That's insane.
And yet there are people who swear by it.
As for the "Death Touch," let me tell you a story. I've made up the story, but I think it is probably true.
Once upon a time there was a Chinese chuan fa master with a large following. On his way home along the waterfront one night, he was attacked by a criminal gang. The master was robbed and beaten senseless by the thugs.
His students found him in a ditch the next morning. They carried him back home. When he regained consciousness he realized that he had lost face very badly. A great master's reputation cannot survive a humiliating public defeat, so he spun the disaster into a triumph.
He pretended to be terribly ashamed. He hid his face, and put ashes on his forehead as if in mourning. He told his students that he was dishonored, not by the defeat --- "that was nothing" --- but by his own moral weakness. In the heat of combat, pushed to desperation, he gave in to temptation and used the Death Touch!
We can imagine the students blinking in surprise. They had never heard of the Death Touch. What was that?
The Death Touch, explained the master, is the secret (five-point palm exploding heart) technique that disrupts the enemy's qi and brings on slow but inevitable death. The master was left unconscious, but his "victorious" enemies had all been killed! Wait and see, said the master. Waterfront gang members will die as the Death Touch works its way into their bodies!
And they did. Their life expectancy was very low (30 years or so), so the odds were that one of the local thugs would die every few weeks. The "qi disruption" theory let the master claim another victory no matter what the real cause of death. Heart attack? It was really the Death Touch penetrating his heart. Disease? The Death Touch opened the door so the disease spirits could enter. Stabbed to death? His qi was disrupted, making him slow and weak in the fight. Every time another waterfront thug passed away, the master's reputation grew.
This is how a master reaps a victory from a humiliating defeat.
Now it is true that you can injure a person so that he takes hours to die. Internal bleeding will do the trick, particularly in a country that has no surgeons. A ruptured bowel will mean a week-long death if there are no antibiotics. Delayed death is possible, but the Death Touch legend is probably the result of a clever spin doctor tending to his own damaged reputation.
But it would be very cool if it were true.
