High tech armor vs Ultra-tech armor

[Anthony]

Originally Posted by Kallatari

Second question. Does distance play a factor? If I was shooting through multiple walls of a building to hit someone on the other side, does the fact that the walls are several metres apart mean they get to use full DR, or are they also root-sum-squared?

Realistically... neither one. The projectile loses energy (based on the energy required to penetrate the barrier) but also might lose stability or break apart. The first doesn't much matter when the layers are close together but will significantly reduce penetration against spaced barriers, the second can be important even against close layers and has the interesting effect that the order of your armor layers matters -- you want the hard armor on the outside, the soft armor on the inside.