"Hit points don’t represent anything solid or real or concrete in and of themselves. Rather, they are part of a complex calculation that boils down to this: “What are the chances that the next moment of mortal peril you experience will be your last.” That mortal peril might be a sword fight, a poison needle, a trap door … anything that might kill you. Most often, hit points relate to combat.
This hits closest to how I imagine hit points work. To him they are an abstract measure of how likely you are to die in a dangerous situation. I think they are an abstract measure of how likely you think you are going to die. Think of it as morale. The player with their knowledge of the remaining hit point total acts like a countdown timer until they cut and run. That's how it could work. There is one problem though. Most players feel they have no other choice but to die when the ticker goes to 0. So many turn into suicide machines fighting on to the better end.To counter this I use what I like to call my AWO option. Another Way Out. Let them escape or surrender and be taken prisoner. What ever the situation calls for.
P.S This is the first part of a two part post.
In the second part I will go into more detail about HPs work as morale.