It only averages out over time.
Of course.
Legend has it that back in the days of proto-D&D, the combat system was one figure vs another, each throws a d6, the highest slays the lower one and is themselves unharmed. The players were unhappy with this, and so Arneson reached onto his shelf and brought down
Ironclads - thus "armor class" and "hit points". Now, if each figure has 1d6 hit points and does 1d6 damage, over many figures and many combats, this averages out to the same result as "throw 1d6, highest slays the lower and walks away unharmed."
But of course a fraction of the time someone will take fewer hit points of damage than they can, and have the option of fleeing the combat - and even if this just happens some of time, it
feels different.
Armor shouldn't act like a "force field" that deflects incoming attacks away such that they never hit you.
Armor doesn't turn you into a "dodge monster" that can't be hit.
It doesn't. But we are not generally interested in whether someone does some cosmetic damage to armour, we are interested in whether someone was
wounded.
In this article, the pseudonymous writer Charles Franklin gives us some real-world wounding results from wartime. He tells us,
"The HERO database indicates that 21% of all hits are scored on the head, 21% in the torso and 58% on the arms or legs."
His language here is imprecise. It's not X% of all
hits, but X% of
all hits which caused a wound requiring treatment which were recorded in a medic's report. It's quite possible that in fact (say) 50% of
hits are on the trunk, but that the wound is so minor it never comes to the attention of a medic. In a boxing match, for example, each fighter will have blows physically connect with their opponent
dozens of times in a match. If you're in the ring, blows which do not do physical harm are still exciting, because you're the one whacking and getting whacked. But if you're just throwing dice, "you hit... for 0 damage... you hit... 0 damage... you hit... 0 damage" will be very boring. We care about the ones which caused something to break or bleed, or knocked the guy out, and this is what a game system needs to simulate.
So this is my mindset. I am not interested in "just a scratch", or a round which went
thunk and was squashed into your kevlar vest and didn't hurt you at all or interrupt your next action or the knife blow which just tore your leather jacket or something. That's just cosmetic, and we assume that after a combat you clean and reload your weapon, sew up holes in your armour or clothing, and that sort of thing. I'm interested in the stuff which might hinder or kill you.
Franklin's article greatly influenced my own game design. I write about this in
Wounding and
Wound Effects.
