That having been said...
This post will likely be short, sweet, and to the point, because the topic is so simple as to warrant a simple approach that highlights the most basic ways of physically managing violence.
There are 2 basic solutions to the problem of social violence: avoidance and surprise. Whenever it is practical and plausible to do so, avoiding violent encounters ensures victory for the good guy and defeat for the bad guy. We (the good guys) get to go home; they (the bad guys) don't get to victimize us. Makes total sense, and I'm all for that as a means of surviving in the world.
When it comes to actual physical response to a threat - fighting - it is best to use the threat's narcissism against him and to our own advantage. This strategy will be less effective against a process predator (an asocial threat whose purpose is to victimize the person not the property) and more effective against a social predator (who wants to establish dominance and/or improve social status).
The narcissist expects you to think like he thinks and act as he acts. That is, when he considers attacking the person, he sees the person as a head and face. Under such an assumption, that is what he attacks - your head. Rory Miller in his book, Facing Violence, beautifully describes the Monkey Dance. It looks something like this:
- the aggressor starts with a question - "What are you looking at, asshole?"
- the 'victim' responds with an equally pithy retort
- the indulgent parties approach one another
- there's a significant amount of verbal jousting
- one or the other players sticks a finger in the other's face and/or pushes him
- a looping right-handed barroom punch is directed at the finger-pointers head/face
It's oh-so predictable, and in my 20+ years of classroom education, I've seen it happen about a thousand times between teenage males.
So how do you beat the narcissist in this kind of situation? Easy. Don't aim for the head. During the 'Approach' phase of The Monkey Dance, preempt the aggressor's attack with an attack of your own (and, once again, I'm writing this with the belief that you're not stupid enough to be the aggressor. As Marc 'Animal' MacYoung and others have said, "Fighting is what happens after self-defense has failed."). There's a lot to be said about the surprise factor associated with a kick to the knees, a stepping-off punch to the solar plexus, kicks to the nerve centers on the inside of the thighs, or a power-packed round kick to the outside of the thigh.
Your preemptive attack does two things: it confuses the narcissist, who was completely expecting you to swing at his head, and it resets his OODA loop as it forces him to deal with the unexpected stimulus of being unable to walk/breathe normally.
Punching at non-cranial targets is a winning idea anyway, given that the bones in a fist can be easily broken against the solid mass of one's skull.
So when your self defense has failed and you find yourself dealing with a threat who can't be talked down, firing that first strike (and subsequent strikes) into non-cranial targets can give you the edge you need to emerge from the melee victorious.
Hopefully you're never in a place where you have to use a threat's narcissism against him, but if you do, it's best to remember that there is no such thing as a fair fight. Playing by the threat's rules is stupid. Beat him at his own game by violating his expectations.