Well if the henchmen flee because their hit points are at 0 from fear of the dragon, they drop dead instead of running for the hills. The dragon's frightful presence made them flee because they couldn't resist it, not because their hit points dropped to zero. If hit points are morale, why are in you in a dying state when your hp drop below zero?
It looks like I need to clarify my point, which is that hit points either went too far -- or didn't go far enough -- in divorcing themselves from physical damage. They hold an untenable middle ground between representing physical damage and representing luck, divine favor, etc.
If warriors were trees, and great warrior were trees with thick trunks, then hit points would model physical damage nicely. You chop, chop, chop away, until you chop through, and the tree falls. But warriors aren't trees. In real life, physical damage doesn't slowly accrue. People don't
ablate. In real life and in adventure fiction, one hit often takes out a great warrior -- and sometimes dozens of hits
don't.
I think we all agree that hit points currently represent physical toughness
plus all kinds of intangibles -- luck, divine favor, plot protection, what have you. In fact, hit points seem to represent
primarily those intangibles, since we know characters don't double and triple in their physical toughness against sword wounds as they gain experience.
So we have a bit of a paradox in our model. We act as if hit points are physical toughness, and they should be lost to "damage" from "hits" with attacks that cause injury, but they clearly represent something else entirely. And now that they can be "healed" by inspiring words and the like, we have to wonder why they can't be lost to "damage" from
uninspiring words, or
harsh language.
But the rules still treat them as physical injury, at least when they run out, which leads to silly results if we allow intimidation to cause "damage" -- because scared warriors should flee the field, not keel over disabled or dead.
So some people would recommend splitting hit points into two buckets --
wounds and
vitality, for instance.
But another way to look at it is to ask why hit points are still associated with physical toughness and wounds at all. If they really are intangible "can still fight" points, why not use them for anything and everything that keeps you in the fight, not just withstanding physical damage from physical hits? After all, those "hits" doing "damage" may or may not be hits doing damage, if we accept that hit points represent luck, etc.
Why not roll toughness into AC, or split AC into one value for
avoiding hits and one for
withstanding hits, and let hit points be used to modify die rolls? If you narrowly dodge a poisoned arrow, that's using up a few points to boost your AC -- via extra effort or divine favor. Then we'd
know you weren't hit. If you take a hit in a barroom brawl, and spend a few points to stay standing, we
know you were hit, but not seriously hurt. And very little changes mechanically.