+Peter V. Dell’Orto discussed how much damage is required to kill in GURPS hand to hand combat the other day. In it, he notes:
Yeah, it’s true. Gunfire can push you to -5xHP so easily I decided it wasn’t even worth discussing. But a post about different pistols and rifles and kills might be worth doing for Doug. Even a “mere” 2d+2 pistol is only a couple of vitals shots from automatic death.
Challenge accepted, though it’s somewhat meager. Just as a setup, you of course take your first risk of death at -HP, and autodeath at -5xHP, meaning that for a healthy guy, you must suffer 2xHP and 6xHP injury in one shot. I’m going to play a bit here, and take that as 24 HP and 72 HP of injury. And I’m doing that very, very much because that’s the average roll on 7d and 21d; for a max roll, you can’t get there unless you’ve got 4d and 12d. That makes the numbers work out to just a bit of overkill (or just the right amount of kill for a slightly-strong target), but also even numbers of dice.
I’m going to be expressing a lot of things in dice rather than HP.
Edit: Some good comments about “out of the fight” and “dead” not being the same in GURPS. Point profoundly taken, but the question that Peter tossed my way was “how much damage is required to kill.” I took that as “in one turn,” because bleeding is optional and (in my opinion) factored into the decision to not deal with blow-through in the 4e rules.
One Word About Armor (for now)
Armor gets a one-word mention here: it’s what you have to bypass to hit the creamy center, and it can get pretty high at TL7 and TL8.
Vitals and Brain
The fact that the brain and vitals’ wound multipliers are x3 and x4 regardless of injury type or size (they overwrite bullet size) means that it becomes generic to look at.
Vitals: To threaten death to the vitals, you must bring a weapon to the fight that does at least 1d+1 or 1d+2. To threaten a single death check on an average roll means you need at least 2d+1. Auto-death is from 4d and 7d, respectively.
Brain: It’s even lower for the brain, of course, but you’ve got that pesky DR 2 skull to deal with. That makes the minimum 1d+2 for the brain, and about 2d+1 for an average shot to force a single check. For auto-death, you can’t do that without a minimum of 3d+2, and you won’t do it on average without 5d+3 or 6d-1.
Weapon me: The short version, with some slop in it. You can get by with a .22 LR pistol (Ruger Standard Mk1) to the vitals, but not the brain, due to the skull armor. A single pellet of buckshot is likewise fine if it hits the vitals, but not the skull. To theaten either vitals or skull, you need 2d+1, which is carry-sized (4″ barrel) 9mm like the Glock 19, Walther P99 or PPQ, or a .40 S&W or 9mm subcompact. In short, a 9mm or .40S&W pistol. Note that a .45 ACP will do for the vitals but not the skull, since it’s only 2d or 2d-1.
For auto-death, you’re looking at weapons that can do 4d minimum to 7d on average for the vitals, and 3d+2 to about 6d-1 for the brain. In short, the only SMG that meets these minimum criteria is the H&K MP7. The P90 comes the next-closest, but doesn’t get there. Basically, upgrade to a full-power subcaliber cartridge to have a chance: even the 10.5″ barrel on a 5.56x45mm carbine like the XM177E1 Commando (4d pi) will do it, but to get to auto-death territory, you want something with at least a 6.8x43mm cartridge (6d from a 16″ barrel) all the way up to a battle rifle (7d) in 7.62x51mm.
Shoot a lot: These are all one-shot numbers. If you are firing at an unarmed person and skilled enough to hit a bunch of times, nearly any weapon can do the trick. All SMGs have Rcl 2 from High Tech, so if you can eke out enough skill to absorb the -3 to the vitals and -2 to hit twice, all of a sudden that P90, with 50 shots, looks pretty attractive. Two shots to the vitals with a 4d carbine racks up 12d in injury to an unarmored foe, which is a fast ticket to auto-death at -5xHP as well.
The numbers for the torso are subject to injury modifiers. But you still need 4d to 7d injury to threaten a death check with a single shot to the torso. That is:
Death check thresholds – one shot to torso
8d pi- minimum
4d pi minimum
2d+2 pi+ minimum
2d pi++ minimum
For a handgun, you have to go a bit nuts. A .44M will do it, so will monsters like a Super Redhawk in .454 Casull or the movie-popular Desert Eagle, whose .50AE cartridge cracks the scale at 4d pi+. I’m sure there are others in the overkill department. Interestingly, a full-sized .40S&W such as the H&K USP, the Glock 22, or the Walther PPQ with the 5″ barrel will all hit 2d+2 pi+, so it’s barely possible to threaten a one-shot death check with a service handgun.
Most assault rifles are in the right range here. Most SMGs aren’t. To average a death check, you need 6d-7d or so injury, and so that’s two hits from a pi+ weapon of decent velocity, or two from a pi rifle type. One hit from a battle rifle in .308 or .30-06 will do it too.
Auto-death is either “bring a .50BMG” whose 6dx2 pi+ technically still doesn’t cut it for auto-death to the torso (18d vs 21d), or shoot people a lot. Three rounds to the torso with a battle rifle will do it.
Final Word on Damage
The moral of the story here is either have a low-damage weapon that you can hit with a lot in one turn, or a much higher one. If you’re looking to drop a foe in one shot, the primary target for an unarmored person is the vitals, not the skull. Skull shots are cool and all but the difference betwen -3 and -7 is two extra hits to the vitals, plus the DR 2 for the skull actually makes it a tougher kill for pistols especially.
More Words About Armor
The torso armor table on High Tech p. 66 hits the key bits that throw the above calculations to the wind a bit. A fragment vest is the equivalent of about 1d+1 right off the top of your weapon, and more serious protection like a a concealable or assault vest is more like 3d+2. That’s before you add trauma plates worth another 7d. If the “dragon skin” concept meets or exceeds manufacturer’s claims (there was some controversy in the past), it’ll soak up about 14-15d (defeating 7.62×51 AP ammo at 2800fps is no joke).
At that point, the torso and especially the vitals become effectively non-viable.
Modern ballistic helmets also grant about 3d+2 (DR 12) to the skull. The Advanced Ballistic Helmet (Pyramid #3/57) is DR 16 (4d+2).
In both of these cases, only a direct hit from an assault or battle rifle, or a powerful SMG with AP ammo will do.
You may even have to shoot at the face, assuming no visor, and hope for that 1 in 6 chance of hitting the skull anyway (optional rule, p. 16 of Tactical Shooting).
With proper armor, the available targets start to get limited. Face, maybe the neck, and limbs.
In a way, there are no surprises here. Aiming for the vitals is a good idea if you have a defensive weapon (read: decent power handgun) and can end a discussion promptly – but likely not force a target into the -5xHP real of auto-death.
A rifle shot to the vitals will have a good chance of ending an argument at -5xHP in one shot, and hitting the torso multiple times can do that too. But note that with Rcl 2, it’s easier to hit the vitals once at 3x damage in many cases than to hit the torso three times – the vitals are the better bet!
If your opposition starts slathering on advanced body armor, you’re going to have trouble. You’ll need to custom-order some stuff, such as an AR-10 platform in .300 WSM (8d+1 from a 20″ barrel) if you expect to face the kind of DR that a modern trooper can put on his chest. At this point, the goal is likely “keep their heads down until your designated marksman or sniper can take them out.”