My post on what guns do in GURPS and storytelling got me thinking about false precision in games that rate damage by HP ablation.
I’ll pick on GURPS, but DnD/Pathfinder is, in its way, not much different. Ironically, I don’t think people really notice as much in Pathfinder, since the entire point of an attack is to whittle away HP until the foe is Dead. Or Dying.
GURPS is a bit different, in that there are a few basically devastating outcomes (because of the one-second time scale) that don’t require HP ablation. You can KO someone with any blow to the skull, for example. Knockdown and stunning, both of which don’t necessarily require large HP subtractions. And lastly, criticals, and crippling of the limbs.
Anyway, here’s the thing. Let’s start with pistols. In common calibers, from about .380ACP to .45ACP (and maybe even including things like the .50 GI) are probably “equally ineffective” when it comes to doing their job. While the .380 is probably a bit anemic, and other cartridges like the 10mm Auto (720 J or so, 200 gr projectiles available? Ow.) are probably on the other end, there are no surefire manstoppers that achieve the goal due to size and power alone – everyone will tell you that shot placement (and a good bit of pscyhology, in addition to physiology) is at least as important, if not more, than joules, kg m/s, and caliber.
Don’t get me wrong – it’s likely, perhaps certainly – true that on the margin, higher energy and momentum and caliber are more likely to achieve incapacitation. But until you up the ante to things like a .44 Magnum (in a pistol caliber), or a .223 or similar high-powered cartridge, you’re really saying that in certain edge cases, you’re slightly more likely to get’r’done than you were before.
What I’m about to do is clearly the act of pondering doing away with Hit Points and going to a wounding mechanism based on something like a HT roll, probably penalized. Probably something like “every HP/2 of penetrating injury is -1 to a HT roll; the more by which you fail, the worse off you are.”
I’m not going to work this one out in detail. Just suffice to say: despite my endless fiddling with firearms game mechanics that are super-detailed in resolution, the world doesn’t really work that way when people are involved; even armor plate is frustratingly variable under real-world conditions.