the hero gets beaten up in an encounter, five minutes later is fresh enough to handle ANOTHER encounter
Except that the entire model for hp itself has no real basis outside the game.
The model for HP was actually how I have always imagined it being explained in comparison to AllisterH's movie character example.
The PC gets beat up during an encounter, but he is still alive and the wounds really don't have any impact on his ability to keep fighting (until he's unconscious). The wounds just bring him closer to death, but he is still whooping butt. When he rests for 8 hours, then he's a bit more refreshed and not as worried about being close to death.
Let's see if I can explain this with game stats:
Rambo has 100 HP.
Rambo gets shot in the arm, but is still fighting (-20 HP)
He gets stabbed in the thigh, but is still fighting (-10 HP)
He gets punched and kicked in the face, but is still fighting (-10 HP)
He looks pretty beat up, but he's alive. Realistically, he probably wouldn't be able to keep fighting. And I doubt I'd want to keep fighting after getting shot & stabbed. But, it's a movie, so he is still left with 60 HPs. He can keep fighting if he wanted or he can go home and rest for the night. But with Healing Surges, Rambo could be 100% health, get stabbed for 5 HP, use a Healing Surge, and be at 100% health again. How can that be explained in the real world?
Just because he was wounded but still fighting doesn't mean that he Healing Surged himself. He just had plenty of HP to keep going. That is how I always imagined HP representing your ability to keep going (even though HPs still aren't very realistic).
Healing Surges to me seem to say that you actually heal wounds instantly. Maybe I'm wrong, but that's what it seems to be saying. I get stabbed, and rest for 5 minutes and my stab would could be completely gone. That's how I see it in Call of Duty...I get shot but survived, then a few seconds later I'm perfectly fine.
