If I'm ×4 strong and my club is ×4 heavy, do I hit you with ×16 force?

[ericthered]

In gurps Terms, you're doing a little over x2 damage. Most of that is from ST. The weight increase grants a flat but not insignificant bonus. One of the low tech compendiums covers increasing weapon weight. But in general, st drives damage, and weapon weight is secondary.

[tbone]

The short answer: GURPS doesn't tackle melee damage with any sort of "here's how the physics works out" approach. I think it could do so (to some degree), and so I've played with all kinds of melee weapon design systems and other hacks, but the system itself didn't take such an approach from the start, and so it is what it is. (And for melee damage stats, etc. apparently created through the "just eyeball it" method, what the system offers isn't bad, IMO! Plus, any sort of fancy-pants physics-based approach is destined to make things some degree more complex, even after lots of reluctant simplifications.)

But your suggestion of "x16 amount of force" is problematic. I don't know what your exact meaning of "force" might be, but just going with the general idea of "how hard I smack ya":

The idea that x4 strength lets you hit with x4 "force" is fine.
The idea that x4 strength lets you hit with x4 the weapon mass is fine.
The idea that x4 strength gives you both of these together is fishy!

You need to pick one: the x4 strength lets you hit with no added mass, but way more speed . . . or with lots more added mass, but at the expense of speed. Not that the end results of the two need to equal out to the same damage, but there's gotta be a tradeoff.

(Keep in mind that, whether the chosen weapon is big or small, the energy going into the blow - the strength - is unchanged. So the work done by the energy - the "damage" - shouldn't vary hugely. Speaking in very general terms, anyway.)

[ericthered]

Originally Posted by ericthered

In gurps Terms, you're doing a little over x2 damage. Most of that is from ST. The weight increase grants a flat but not insignificant bonus. One of the low tech compendiums covers increasing weapon weight. But in general, st drives damage, and weapon weight is secondary.

To be specific, Low Tech Compendium 2: Weapons and Warriors, page 21.

Using specific numbers, a knobbed club from LT65 does +1 cr damage. If we scale it up for use by a SM+2 creature, it does x2.5 times the damage bonus, or +3 cr damage.

A ST 10 wielder of the club does 1d+1 cr damage. A ST 20 wielder of the original club does 3d+3 damage, and a ST20 weilder of the enlarged club does 3d+5 damage.

So most of the damage increase comes from improved ST, but some of it comes from a properly sized weapon.