Hey,
From the wiki I can tell that Concentration checks to see if you keep casting your spell are a d20 + your concentration score vs. 10 + damage received + level of spell your casting.
How does Invulnerability and other DR factor into this? If I'm a favored soul and walking around with a DR/15 Adamantine, does that DR effect the target number I have to hit? or is it raw damage before any mitigation that is used in the calculation?
Thanks!