Writing up metallurgy for a campaign

[Fnugus]

Originally Posted by Polydamas

GURPS does not define "strength" in that context. It defines DR as resistance to penetration by projectiles, and scales it so that RHA steel has DR 70/inch and other materials have strength in proportion. Some people find the proportion by research and others make it up.

Sure. The big question is, in relation to GURPS game balance compared to weapon damage output, how does it scale? Does half the RHA of steel means half the DR?

Originally Posted by Turhan's Bey Company

The problem--or, at any rate, a problem--is that I suspect that you're after a formula which is far beyond the scope not just of GURPS but of just about anyone who isn't a technical specialist.

Haven't someone made a "formula" for damage in relation to "muzzle velocity" or some other measure of power for HT and UT weaponry? In that case, how? And how does it compare to the stats of armors/DR?

Originally Posted by Turhan's Bey Company

As I understand it, RHA-equivalent is sort of the yardstick for discussing modern armor, so people who come to GURPS with real-world armor stats expressed in RHAe can come up with an equivalent DR. However, coming up with an RHAe for something is what scientists call Very Difficult, and doing the massive work involved is the realm of materials engineers with government grants. So GURPS authors don't have a method for determining DR beyond:

1) If there's a published RHAe for the material/item, use that.

2) If not (which is probably universally the case for anything historical), make something up that looks good.

At any rate, even if you were to come up with RHAe values for a range of the sorts of alloys one finds historically, the inability of ancient smiths to precisely control their materials and manufacturing conditions puts some significant error bars of the quality of what they make from batch to batch. So you'd end up having to track a list of "Platonic ideal" materials and how close any given smith got to that on any given batch of material while smelting and alloying and the extent to which a later smith, making an item from that batch of metal, changed it. Oh, and without sophisticated testing technology, neither the smith nor his customers will be able to tell the difference with much more granularity than "this is junk," "this is OK," and "this is pretty good."

Which is all pretty good. The idea is just to get some sort of guideline as to what RHAe means in relation to DR. And for this, only a select few handful of materials are needed stats for. Just three would do, I think, if stats for both DR and RHAe could be had. That's enough to extrapolate from. Just finding the relation/ratio/scale between RHAe and DR in the first place is what I'm after.