Making EM Guns Viable in Space Combat (3e)

[Rupert]

Originally Posted by Varyon

That's available as an optional rule in "Alternate Spaceships" (Pyramid #3/34), where the more armor you have the better each module of it protects (because the spaceship becomes smaller, and thus has less surface area for a given quantity of armor to cover), and there are certain breakpoints at which the spaceship becomes one or two SM's smaller than its weight would indicate.

That does not account for the differences between armour types' density, only between the density of a ship without much armour and one with lots of armour.