High tech armor vs Ultra-tech armor

[Rupert]

Originally Posted by weby

In Gurps damage and peneration are calculated as square root of energy, so if the system was internally consistent it would use that as scaling, that is adding a second of same DR would multiply the result by 1.4 effective DR instead of *2

Except that while it's roughly true of flexible armour and discrete layers of hard armour, single thick slabs of hard armour tend to resist penetration such that it takes energy proportional to the square of thickness to penetrate (roughly).

Thus while doubling the layers of ballistic cloth might mean DR goes up by about x1.4 times, doubling the thickness of a Ballistic plate roughly doubles its DR.

That said, because layers even hard plates isn't as effective as adding thickness to a single plate, ruling that extra layers add less DR wouldn't be unreasonable. Halving the DR added by the weaker layer (and perhaps quartering that of the 3rd+ layers) would be reasonably simple.