A single Ioun stone and Heirophant for 5 levels, maxxing out the Spellpower.ConcreteBuddha said:We are talking about a normal game, right? So there may be one NPC in the entire game with that level of spell penetration. Every other NPC is stuck with SP and possibly GSP.
The other +6 that you are getting from mysterious sources does not really matter, IMHO.
And boosts enemy clerics SR penetration by 4, as well. What's good for the goose, is good for the gander, after all. And spell girding helps against Dispel attempts, not SR penetration.Besides, the bead of karma boosts the cleric's SR by four. I also forgot the orange ioun stone. I'd add in spell girding (effectively making it +2SR), but then I might have to add something from another non-core source, so I'll leave that out.
I'd say your campaign may be the one that is abnormal. Do you often throw paper-mache enemies against the "PC Meatgrinder"?This is also neglecting that most NPCs are lower caster level in the first place. (Unless your campaign is abnormal)
Spellcasters worth the defensive spellwork tend to be equal level; BBEG-type spellcasters tend to have 3-6 levels more than the average PC.
Again: if the Cleric can have the Bead, so can the NPC, if he's a divine caster.So say a PC cleric has 12 +cl +5 (bead of karma and orange ioun stone, both core)
The NPC would have 1d20 +cl +4 (SP and GSP)
Only because you presuppose a higher modifier for the PC than the NPC. That isn't always going to be the case.17 to 14.5 if their caster levels are the same. PC Cleric wins 57.5% of the time.
Two casters at your level would be a CR of Party Level plus one. Mildly challenging, not overpowering.That's also assuming that the caster levels are the same. (Which would mean one caster at your level for a balanced encounter. Two casters of your level would be overpowering.) Most encounters have casters that are 1 or more caster levels lower than the PCs.
A caster of Party Level, plus or minus two, with a mob of lower-level mooks/goons/thugs, would be a moderately challenging encounter.
Cast on one's self, Nondetection's base DC is 15, plus caster level. So even if the NPC is five levels below the cleric, that puts it to a fifty fifty chance. At even levels, that makes up for BOTH the ioun stone, AND the bead of karma, and keeps it at fifty/fifty.Of which a PC cleric has a better than average chance of ignoring, considering a PC is generally a higher caster level than NPCs, the bead of karma, and the orange ioun stone.
Throw in caster level boosts of some sort for the NPC (spellpower, an ioun stone, a bead of karma if he's a cleric), and it swiftly degenerates from there.
That wouldn't be supported by the rules, however. You'd know there was a mirror image spell going, but you would not be able detect which of the images was the REAL target[/b]. Not without that caster level check (which, BTW, is one caster level check where Spell Penetration is useless). So while you'd know that, say, five of the six Big Evil Wizards infront of you weren't real ... you wouldn't know WHICH of those six were the false ones, and which was the real one.And anyway, True Seeing says it sees through illusions. Mirror Image creates illusions. Nondetection effects a creature or an object, not the mirror images surrounding you. (At least, that's my interpretation of it.)
That's rather the point of Nondetection, after all.