Does the spellcasting AI take MR into account when choosing spells? In a castle I just stormed, my 3 level 4 nature mages cast stream of life unsuccessfully 38 times against the naga pretender. If they had chosen orb lightning (and they had higher air magic than nature) or even lightning bolt they'd have crushed the naga easily.
Their penetration value: 11+[(4-3)/2 rounded down=0]+2d6 (oe I assume as manual says approximately, and they did finally succeed) for a total of 11+2d6(oe).
Naga resistance value: 21 + {[Nat 7]/2(does not say if rounded up or down, lets say down for best case)=3}+2d6(oe)=24+2d6(oe).
Therefore, it is mathematically impossible to penetrate the MR without getting the (oe) part of the roll. Not to mention that the spell only kills 40% of the time that it does penetrate MR, the rest of the time it
benefits the target.
With those numbers I could roll an
awfully long time before I succeeded. Heck, I could roll an awfully long time before I even penetrated MR, and then have a 60% chance of helping my opponent.
On the 39th attempt, the naga finally went down. In the meantime, according to the spell, every time the spell bypassed MR but failed to kill, the naga was healed, got stronger, and went berserk (which was fine for her as she was feebleminded). Fortunately I killed her right as the troops broke through, or she would have been massacring my rather expensive army while
I healed her.
If the spellcasting AI is supposed to take MR into account, I think it needs an update. If it's not supposed to, can it be modified to not cast Stream of Life unless scripted, or at least not cast it more than 5 times in any given combat? Pretty please