There is not an armor as DR option. The following variants are in the book:
- Ability Score Variants (gradual ability boosts, point buy, alternative scores)
Behind this line hides one of the few variants that piqued my interest (as one having seen similar efforts in too many editions already)...
Basically, you can play PF2 using a different set of six ability scores:
- Agility
- Brawn*
- Dexterity
- Charisma
- Wisdom
- Intelligence
Apart from a small number of gameplay tweaks, the following is all there's to it:
Agility represents footwork, and applies to Armor Class, Reflex saves, Acrobatics checks, and Stealth checks
Brawn* represents Strength and Constitution and is used for everything from damage rolls to Fortitude saves
Dexterity represents manual dexterity and applies to ranged weapon and unarmed attack rolls, attack and damage rolls with finesse attacks (if better than Brawn), and Thievery checks
Charisma is used for Will saves
Wisdom is otherwise unchanged
Intelligence remains unchanged
*) The GMG fails to make up a cool new name that avoids confusion with the old names so I did it for them
The section completely fails to discuss the impact of this variant, though. It's just dropped into the reader's lap.
The text does claim that the RAW abilities are created unequal and this rearrangement makes them much more equal. And for rollplayers and murderhobos that may be. But for anyone involving NPCs and society in their campaigns Charisma is definitely not a dump stat already before this change.
This variant does switch up the old wisdom "let Constitution always be your third best stat". Finesse fighters and spellcasters will likely find that the cost of getting bonus hit points per level has increased now that they need to increase the former Strength stat!
I am not sure Rogues in particular were in need of a nerf, which having both Dexterity and Agility functionally amounts to. On the other hand, it makes Rogue's Thief Racket the default everybody gains, enabling the Rogue player to just gain Thievery and take a different Racket, so there's that...