| HammerJack |
Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Adventure Path, Starfinder Roleplaying Game, Starfinder Society Subscriber
Quote:
A fortification rune wards against the most deadly attacks. Each time you’re critically hit while wearing the etched armor, attempt a DC 17 flat check. On a success, it becomes a normal hit. This property thickens the armor, increasing its Bulk by 1 and the Strength required to reduce its penalties by 2.
That says "becomes a normal hit" not "does not do double damage". So that should prevent everything to do with being a critical hit.