Pyramid #3/52: Low-Tech II

[Langy]

Originally Posted by Anthony

I don't have the issue, but 1 square foot with a thickness of 1" has a weight of roughly 5 lb * Density (so 40 lb for 1" steel). Max DR is probably empirical, realistically the reason you don't use Kevlar against rifle-class threats is because it has poor scaling (realistically, given how GURPS DR works, the DR of fiber-type armors should vary with the square root of weight) and generally performs poorly against high velocity attacks, not because it has a true maximum.

The 'Max DR's are said to be chosen because any thicker amount of armor wouldn't be reasonable to wear - it'd hinder movement too much, etc. This is half of the DR/inch for most Flexible armor (except Cloth, which has it listed at a full inch of armor), greater than an inch of DR for Wood armor, and about 1/5 of an inch for most metal armors. It's 10/75th of an inch for Lead armor and 1/6 of an inch for some metals. It's about 1/2 an inch for 'stone'-type armor.

I honestly have no idea how a lot of these things were decided.