Unifying Corrosion and Ablative

[Tyneras]

Corrosive damage and ablative DR are two sides of the same coin, and I think they can be more closely unified.

First, Corrosive Damage is changed from it's own damage type into a damage modifier. The supermajority of existing corrosive damage would be burning (no incendiary) damage, followed by toxic damage, with a handful of outliers like cutting corrosive damage from the Nanothorn Blade (UltraTech page 164).

After that comes smoothing out the values of each available, being written as (Corrosive #, +%) or (Ablative #, -%) modifiers. I don't pretend these are perfect values, but they fit well enough. The value representing how much damage reduces the DR by 1.

Value Corrosive Ablative
10    50%       -20%
9     60%       -25%
8     70%       -30%
7     80%       -35%
6     90%       -40%
5     100%      -45%
4     125%      -50%
3     150%      -60%
2     175%      -70%
1     200%      -80%

Resolving corrosive damage on ablative surfaces, the simplest solution is to use the lowest number.

Corrosion-Proof DR
Transhuman Space Shell Tech (p.5) has the acid-resistant enhancement for the Sealed advantage, which amounts to 6 points to be immune to corrosion from strong acids. Moving this enhancement to DR directly, at +10% for strong acids will equal in value after 12 points of DR, and +20% for immunity to all corrosion effects would equal out over 6 points of DR. This strikes me as reasonable, this becomes expensive quickly for significant DR.