OK, so I have a +1 Defiant (undead) heavy shield. What's my AC bonus vs. a ghost (or other Incorporeal undead)?
+5 (+2 shield, +1 magic, +2 defiant (undead))
+2 (only the +2 defiant (undead) works)
+0 (It's incorporeal and you don't get the +2 even though it's undead)
Also, do I get the DR 2/- vs. Incorporeal undead?
OK, so I have a +1 Defiant (undead) heavy shield. What's my AC bonus vs. a ghost (or other Incorporeal undead)?
+5 (+2 shield, +1 magic, +2 defiant (undead))
+2 (only the +2 defiant (undead) works)
+0 (It's incorporeal and you don't get the +2 even though it's undead)Also, do I get the DR 2/- vs. Incorporeal undead?
If it's making an incorporeal touch attack (or a regular touch attack somehow) then it ignores your shield bonus to AC.
If it was hitting you with a ghost touch weapon or something, then the full AC would apply.
I assume the DR would apply to any physical damage it dealt to you.
-edit-
Defiant is not a force effect, it just increases the item's enhancement bonus to AC. So against an undead, your +1 Defiant (undead) heavy shield acts exactly like a +3 heavy steel shield (with bonus DR2/-). Since a touch attack disregards your shield AC bonus, that includes any enhancement bonuses to your shield AC.