Making a Heavier Version of a Melee Weapon

[JCurwen3]

A player that likes his character to wield a great axe (as per Low-Tech, p. 70) asked me if he could have one made, given the cash, that was heavier, under the idea that his super-strong (ST 80) character could take advantage of the heavier weapon and have it do more damage.

I'm not sure that his logic is sound, so I'm asking here. The standard great axe is 8 lbs, does sw+4 cut, and has a minimum ST of 12. If another great axe was made that used denser materials, but was otherwise of the same shape and size, could that boost the damage it could do? How would I calculate the new minST of the weapon based on the use of denser materials?

[johndallman]

Given that with a ST 80 character realism has retired to the beach, you could double or triple weight, and modify the MinST by the same factor. That raises the MaxST, which is 3xMinST, and allows him to do more damage.

LTC2: Weapons and Warriors has a weapon design system which doesn't cater for these levels of ST, but does have a lot of other options that the player may find interesting. The 15lb swiss-army polearm is particularly fine.

[Nereidalbel]

You'd need to find some sort of ultra-dense material to make an axe that heavy.

If magic is a thing in your setting, get Shatterproof on an axe made of iridium and even your ST80 guy will put some effort into swinging it. The axe will even be immune to conventional acids and resist temperatures that would melt his flesh!

[Ejidoth]

It will generally require implausible materials for weapons since you're increasing the density by quite a lot, but in general, as long as you're changing just the material and not the size or shape of the weapon, you can power it up like so:

1. Multiply its MinST by some number, I'll refer to it as X.
2. Multiply its actual weight by X squared.
3. Multiply any damage modifiers it has by X.

This looks counterintuitive at first glance, because some weapons have zero or negative bonus, and multiplying those seems to make the weapon heavier for no benefit or even appears to make it worse.

Remember that triple a melee weapon's MinST is the maximum ST you can use with it, so even in cases where the bonuses aren't impressive, heavier weapons let you use higher ST.

A hatchet does swing cutting damage, no bonus. It weighs 2 lbs. and has a Min ST of 8. If your ST is more than 24, you can only use 24 of your ST safely to attack with the hatchet.

If you make a hatchet out of some super crazy dense material so its Min ST is 80, it only does swing cutting damage, because you're multiplying a damage bonus of +0 by 10, which still leaves it at +0. You now have a hatchet that weighs 200 lbs, requires 80 ST to use effectively, but lets a super with 240 ST use his full strength to do some serious swing/cutting damage.


The main reason these rules don't work well for scaling weapons to large and small characters is that it doesn't really account for stuff like changing the size of a thrusting weapon's wound channel, or how long it takes to attack with a swing weapon and what affect a longer or shorter lever arm should have on the damage. But if you're just changing mass without actually scaling the weapon any differently, multiplying's fine.

EDIT: Technically, if you want something that's more physically accurate, step 3 is a little more complex. Weapon damage should really scale with the cube root of its weight (i.e. with its HP), not with the square root of its weight (i.e. the ST required to use it.) But the math gets weird there, and doing it the way I outlined above is balanced enough since it lets appropriately-massed weapons provide proportionate benefit to any ST.

[Fred Brackin]

Originally Posted by JCurwen3

A player that likes his character to wield a great axe (as per Low-Tech, p. 70) asked me if he could have one made, given the cash, that was heavier, under the idea that his super-strong (ST 80) character could take advantage of the heavier weapon and have it do more damage.

A basically canonical but slightly odd method is to use the Gada rules from Martial Arts.

Those allow for Gadas of arbitrarily heavy weights and adjust damage in the process. See Martial Arts p.216. To change a Gada from min St 16 to ST80 multiply weight by 5. It's now 75lbs and probably solid metal instead of wood and does swing +25 cr.

Then use the Combination weapons rules. You need the slightly more complete ones from LTC-2 p.13 rather than the ones in MA. Adding an axe blade to one side adds a lb of weight but doesn't effect Min St. Damage is now Sw+24 cut.

<shrug> As I said it's slightly indirect but I think it's legal.

[Brandy]

RPK has a house rule for this that works well.

[Varyon]

Originally Posted by Bookman

RPK has a house rule for this that works well.

Indeed. For the OP, you should probably aim at MinST 53, so that the character will have the necessary 1.5xST to be able to use the weapon without it becoming Unready after each attack.

Using RPK's guidelines, that's 19.5x the weight, or 156 lb. That's 148 lb heavier than the original weapon - let's bump weight up by 2 lb (not enough to change MinST) to get that an even 150, which corresponds to +11 to damage. Such a weapon has a base cost of $4389 (which may need to be adjusted if special materials were used to make it so dense).

[Kuroshima]

Any reason why he can't have a SM+2 version.amd get not only increased damage but also increased reach? Give it a SM+1 grip, and make the character take the Huge Weapons perk, and he can use it without penalties.

The rules for oversized weapons are in GURPS Low Tech Companion 2: Weapons and Warriors and the Huge Weapons perk is in GURPS Power-Ups 2: Perks

[Philomath]

GURPS Martial Arts, p. 214 also mentions increasing a weapon's ST when increasing its weight. The rule is for combination weapons but I can't see why it wouldn't apply here. Of course, the limits of material weights might (read almost certainly) come into play when changing the mass so much but that's a whole different question.