Posted this in another thread but I think its a good enough idea to deserve its own thread to discuss.
First off no - THIS IS NOT A NERF SUGGESTION. This would be ADDITION to the existing flat numeric DR.
I think shield blocking needs to be upgraded to a percentage. As thats where the games heading where we have 1000+ (and even 2200+ with the new arti buff and epic destinies) HP tanks, and bosses (Lord of Blades can do this) dealings 500+ damage in 1 hit, the old 5-30 DR system barely scratches the surface of our power and the enemies power. Fixed numbers just end up either game breaking (DR blocks all damage because the monster hits fast, but for low amounts) or too weak (Lord of Blades hits you for 500, 20 was stoped.. Who cares? should of just not blocked and kept swinging)
I'd suggest:
Martial "Tank" Classes (Full BAB, d10 HP or higher):
Thus - Ftr, Bbn, Pal:
When blocking with a non-shield (two hander, twf, etc): +50 PRR
When blocking with small/heavy shield: +75 PRR
When blocking with a tower shield: +100 PRR. (This only works if you proficent, else you get the regular shield +75, to discourage ppl from using shields they arent prof in just to block)
This stacks with shield masterys current bonus. (tho keep in mind, shield mastery is now PASSIVE, and this Suggestion purely has to do with ACTIVE blocking)
Tough, non-tank classes (Full BAB, D8 HP)
Thus - Ranger, Monk:
When blocking with bow/two hander/two weapon/wraps: +30 PRR
When blocking with small/heavy shield: +50 PRR
When blocking with a tower shield: 80 PRR (This only works if you proficent, else you get the regular shield +50, to discourage ppl from using shields they arent prof in just to block)
Squishies (Less than Full BAB)
When blocking with bow/two hander/two weapon/wraps: No physical damage resistance.
When blocking with small/heavy shield: +10 PRR
When blocking with a tower shield: +60 PRR (This only works if you proficent, else you get the regular shield +10, to discourage ppl from using shields they arent prof in just to block)
To qualify for these bonuses you can't splash.. Your class icon must match the class listed. (So 11 levels of ftr is enough, but 9/10 may not be)
Similar to the current shield mastery feats upgrade. But different in that the shields function all the time while wearing a shield... These would only function while active blocking (and facing the enemy)
Tho on the subject of caster shield DR: Imo in the cases of some 0% ASF shields, I think there flat DR should be lower then ones which can't get to 0% ASF.. And Currently that is true (Epic warding shield is 0% sloted, DR12, Lorriks champion is 15% ASF, DR15), and I hope it hold true for the upcoming alchemical shields also, and that they get a good base DR for the heavier/higher ASF ones.