Where to find information on material DR

[bocephus]

You specifically mention metals, I had this come up with something like it in leather. And couldnt find a RAW on skinning or processing the results.

This is a concept I came up with to deal with unusual creatures that might have useful characteristics. I had a rather enterprising naturalist that was set on making some extra cash. Its a D&Dish type world.
Price is based on the world price generally low tech TL4ish. Its somewhat extrapolated from RAW values and fairy dust.

My house rule "how much hide did you skin" formula is size(1) plus size modifiers times half the skill success number x10 = weight in pounds of usable untanned skin/hide

wolf size 1, no SM, rolled against survival skill 13 succeeded by 6
(1+0)x(.5x6)x10= 30lbs untanned hide.
Cow size 1, SM+1, rolled against survival skill 13 succeeded by 6
(1+1)x(.5x6)x10 = 60lbs usable untanned hide
Giant Dingbat 1, SM+3, rolled against survival or naturalist skill (minus 2 cause the DMs a jerk and the PC has never seen a Dingbat before) succeeded by 4
(1+3)x(.5x4)x10=80lbs of usable untanned Dingbat hide (apparently not much on a Dingbat is skinable, probably all the carbuncles)


Tanning costs 1-2sp a pound for normal leather (use the CF to calculate exotic prices)

NPC Tanning per pound results in 20% + 1dx10% pounds of tanned material
PCs Tanning per pound is 20%+ margin of successx10% pounds of tanned material
There will always be loss in the processing, and parts of the hide might just not be that usable. In my formula that loss is always at least 20%

Heres a leather I made up:
Umberhulk Carapace

DR4 with the same weight as Med Hardened Leather (DR2) items (use Med leather stats and just add +2 to the DR)+4 CF
HQuality harvest is additional +1DR and additional +4CF

So it costs per pound 5sp-10sp for regular and 9sp-18sp for HQ to have it processed.

It seems complicated but once you have a formula its just a matter of deciding the CF of the new leather type that represents its value and then applying it to the formula.

The mechanics help keep the market from flooding with exotic leathers but still give a player an understandable mechanic to participate in the economy. GURPS Low Tech gives you all the details you need on how much each piece weighs and if the particular method results in shrinkage (IE Hardened leather needs 25% more material for the finished product). And a motivation to do a try to gather the components for things like armor. A med hardened leather torso is DR2 weight15 and costs $125
To buy that in umberhulk with a DR4 weight 15 would cost at least $625 but you could probably get it made for $100-200 if you supplied the raw materials.

Hides vary wildely on useful, or not, attributes. Some are heavier but have metallic properties. Some have scales that take enchantments easier, or a Hide that retains a bit of its chameleon like properties (it blends somewhat to the major colors around it giving modifiers to concealment). Some are heavier with no added benefit, or degrade quickly, or are thin or just yield a product that is the same as cow leather. Not every creature has a desirable hide.

I have an idea for farming a creature like a rust monster to create hides with specifically controlled qualities (based on what they are fed) for a subterranean adventure line that has just never gotten to the point of needing to develop it in detail. Think a Drow/deep dwarf/svirfneblin type culture.

[SClay]

As far as hides I am going with roughly the DR of the creature they are made from with a variance for quality.

but using the inch bar base for DR isn't really useful for armor, as most armor plates are going to be around 1/8th of an inch to 1/4th at most.

larger than that and you run into engineering and mobility issues.

thinner metal does not scale as well as thicker. realistically this makes sense, this is a development curve of sorts, but it leaves the current system with steel armor that has pretty much the same value as heavy leather, and does not allow for new materials (Be they metals or exotic hides)

my current attempt at a solution has been consider a plate male chest piece as my zero mark and figure out what would be different if that exact plate piece were made of something different.

is metal X more or less durable, at the same thickness is it lighter or heaver, does it bring new features like electrical resistance to the table.

then from these base comparisons I create a variance. which I store in a spreadsheet and use to modify or make new armors as needed.

it is less hard numbers and more spitballing the initial effect but I think it fits the spirit of high fantasty or loose scifi better

[hal]

Originally Posted by SClay

As far as hides I am going with roughly the DR of the creature they are made from with a variance for quality.

but using the inch bar base for DR isn't really useful for armor, as most armor plates are going to be around 1/8th of an inch to 1/4th at most.

larger than that and you run into engineering and mobility issues.

thinner metal does not scale as well as thicker. realistically this makes sense, this is a development curve of sorts, but it leaves the current system with steel armor that has pretty much the same value as heavy leather, and does not allow for new materials (Be they metals or exotic hides)

my current attempt at a solution has been consider a plate male chest piece as my zero mark and figure out what would be different if that exact plate piece were made of something different.

is metal X more or less durable, at the same thickness is it lighter or heaver, does it bring new features like electrical resistance to the table.

then from these base comparisons I create a variance. which I store in a spreadsheet and use to modify or make new armors as needed.

it is less hard numbers and more spitballing the initial effect but I think it fits the spirit of high fantasty or loose scifi better

David Pulver published rules for the making of armor from TL 0 (historical or fantasy) on up to the highest Tech levels for sci-fi. Just going with the material for his first article (there were two sets of articles, one for historical/fantasy - the other for Moderns and Sci-fi). See if the material list is worth your while. If you like the articles, then you have the basis for deciding what the DR is of any given material and standardize it for your campaigns:

Bone (TL0):
Cloth (TL0):
Horn (TL0):
Leather (TL0):
Wood (TL0):
Bronze, Cheap (TL1):
Bronze, Good (TL1):
Copper (TL1):
Stone (TL1):
Iron, Cheap (TL2):
Iron, Good (TL2):
Lead (TL2):
Steel, Strong (TL3):
Steel, Hard (TL4):
Adamant (TL^):

Let me know if you want to know which Pyramids contain the two articles, or you can search for it yourself. Who knows, you might find other Pyramid articles that are must haves. ;)

Addenda: The titles on both articles are:

EIDETIC MEMORY LOW-TECH ARMOR DESIGN
Eidetic Memory Cutting-Edge Armor Design

Hal

[Rupert]

Along with Low-Tech Armor Design (Pyramid 3/52) and Cutting-Edge Armor Design (Pyramid 3/85), there's a third: Ultra-Tech Armor Design (Pyramid 3/96).

[hal]

the nice thing about those articles is that you can create your own materials, and figure out how many inches generate a given DR, along with how flexible (or not) your fictional armor material is, as well as the weight per given volume of the material in question.

In theory, one could easily use the guidelines from the Pyramid articles, and retrofit the original GURPS 3e armor materials and work out your own suits of armor as you see fit.

Just a thought...

[Polydamas]

Originally Posted by SClay

A player brought up an obvious but glaring oversight in my knowledge. He wanted to consider various metals for armor or weapons.

Like Brass swords or armor of a given type VS Iron or steel of the same type sword or armor

I have assumed the mass change is negligible enough that damage really won't change in most cases, though it should affect DR of an object and possibly it's ability to keep an edge.

Is there a good place to find this kind of info. and while I am at it I guess I should go ahead and expand my knowledge to common Fantasy materials if possible such as Mythral.

There are some rules for low-tech and high-tech armour of various materials in Pyramid: Pyramid 3/52 is one issue among two or three.

Weapons are really really complicated, TL 1-5 steels are very hard to model and so are toolsl. And the bronzes used for weapons don't match any of the standard modern alloys, because those alloys are designed to make modern things and hit modern price points not make bronze age things and hit bronze age price points.

Follow Ken Hite's Law and use reality as your setting: if something the size and shape of a Broadsword existed in bronze, it should have Broadsword stats in GURPS. If you can't find a model, then its probably not practical to make that GURPS weapon from that material.

[SClay]

Thanks I will look into the pyramid volume you pointed to.

as far as TL, I honestly don't see it as important at this time.
the campaign is TL 4~5 but is also high fantasy and that tends to skew things a bit if you are not just using it as a sugar coating like many settings do.

if magic is a part of the world and these materials are common enough to be recognized by most applicable merchants and or artisans, then access to and manufacture with these materials is pretty well on there way. probably bolstered with respective crafting magics.

I am trying to avoid certain common tropes such as ALL elven armor is Mythril or all X race's weapons are made of X-ium. it's silly if you think about it especially if the material in question is rare.

so my player's question about material makes sense for rounding out the world.

still ironing out my approach but will try to remember to share my results.

[SClay]

purchased and looked through pyramid 3/52.

it does cover the necessary rules, you can make armor that way.
I really don't see the value of the hyper focus on TL outside excluding materials and production types, which should be a consideration of the campaign setting usually,
not really as useful for the crafting of an item itself, and rather than an equation things like "Don" could probably benefit from a chart and have the equation as a foot note.

it would streamline the creation process (which is currently 8 steps, per piece of armor)
It feels a little clunky to me, so I am probably going to set up a spreadsheet with all the right data for quick use.
Computers were practically made for set it and forget it math.

[Polydamas]

Originally Posted by SClay

I really don't see the value of the hyper focus on TL outside excluding materials and production types, which should be a consideration of the campaign setting usually,

Its because armour and metallurgy are technologies, so what you can do depends on the surrounding society. "Bronze" "brass" "iron" and "steel" are shorthand for a world of complexity which actual artisans and factories have to deal with. You could not make a 15th century CE suit of plate armour with 5th century BCE iron and craft skills, you can make much more impressive bronze swords with Early Iron Age Age technology than with Early Bronze Age technology.

[(E)]

Here is some noodling about the DR of various woods.

https://www.ravensnpennies.com/the-h...tough-is-wood/