I’ve read some fairly interesting blog posts about the strength-based damage in GURPS, about how it’s too high or priced too high, or what have you. The numbers certainly seem high enough, as a regular man can chop through chain mail and what have you. I thought that I (like so many others) could look over the numbers. Then I realized I have some statistics from some questionable internet article(s) I read once and noted down…
Warning: may contain grave use of assumptions, and making untested and/or drastic changes to your favorite (?) game system. Parental supervision is advised.
Facts From the Internet, Without Sources
- An expert’s fighter’s punching force: 5000 Newton.
- An expert fighter’s kicking force: 9000 Newton.
- 3300 Newton: 25% chance of a broken rib.
- 4000 Newton: might break thigh bone.
- Kinetic energy of a karate punch: 150 – 450 J
RAW Punching Damage
Now it’s time to make assumptions. These fighters had Karate at a level granting the +2 damage per die damage bonus, and were making an All Out Attack (Strong) for another +1/die. This means a total of +6 damage if they have two damage dice… Or +4 if they have one. Punches are based on thrust damage -1, kicks plain thrust. According to the numbers, kicks have 180% of a punch’s force. In the rules, kicks just deal 1 more damage. The difference should be just a tad bigger I think.
There are two examples of damage in these things I found. One is kind of vague, saying that 4000 Newton “might” break a thigh bone, while the other has a concrete number to go on. These damage numbers should both certainly be considered major wounds, as a broken rib is quite bad, and a broken thigh bone is a crippled leg. Dealing a major wound requires more than the target’s HP/2 damage in one strike, which is 6 points of injury against a regular HP 10 person. If we scale up the 3300 N to the full 5000 N, that should mean (unless force and damage doesn’t scale linearly with each otther) that there’s a ~37% chance of a broken rib. That means a roll of 5 or 6 on a single die should do the job. This pans out to 5000 N being 1d+1, or maybe 1d+2 punching damage with training and All Out Attack. Probably. The kick should do 1d+3 damage (again, if force scales directly and linearly with damage dealt), compared to the 1d+1 damage.
If we, for fun, use the ballistic formula that Douglas Cole made (here, for example), to calculate how much damage a fist should do based on the kinetic energy numbers, what would happen? Well, the 150 J range is pretty close to 1d-1 damage, and the 450 J range is near 1d+1. That’s interesting. Not that hands are actually bullets though, but it still fits pretty well with the numbers from above. I read somewhere that karate practicioners strike with a little less force than, say, boxers (probably because of different techniques and styles of fighting).
Extra Assumptions [5 points/level]
This makes it clear that unarmed damage is a bit cinematic in GURPS, and maybe even melee damage in general. What could you do about that?
So if we are rescaling punching damage, what should we calculate the maximum strength as? I’d say 20 for now, including striking strength. This might be a bit low by RAW, but I’ll possibly drop a post about a “max 20” idea that might or might not work out later. I’ll then count the damage bonus from karate as a +1 striking strength… Which is a bit weaker than now, but probably more reasonable. (+1 per die is about +30% increase actually).
So if our fighter has at most 20 strength total, or a little less as the fighters from the study might not be the absolute top strikers, and merely being very good. As 1d+1 damage (with -1 for unarmed, and +1 for all-out-attack… I just nerfed this, did I?) averages 4,5, maybe damage points is simply equal to strength/4. That’d put the base damage of 20 strength at 2d-2 if you want to keep it even. You could probably roll with your striking strength being modified by a percentage based on your weapon, as a replacement to thrust and swing damage. Then you would have to change the way that weapon damage works completely, but it could be good. I won’t do that right now though, as that could do with a bit more thinking and I don’t really have the time at this exact moment. Interesting, though.
Also, I’m sorry if this post is ranty and/or confusing. I have written on it here and there, mostly on nights when I was tired and possibly had something else to do. But the idea is still fun. I will probably come back to this at a later point and maybe do some more math or roll out the physics wagon. Yay!
[Pre-written and auto-published at a later date. When this is released I’m away a few days.]