[PvK]

Well it would seem like frozen heart should only work on things that don't like cold. If cold-immune undead are being hurt by it, than I expect cold-immune ICE ELEMENTALS are too, no?

Whether various undead types should be hurt by frozen heart or not... seems unknowable - one would just expect the devs to decide and if you're lucky, to give hints before you have to try it in practice.

But there are some other effects in the game which mention hearts, and some creatures which might not be expected to have them (vine creatures, golems, claymen, elementals, mummies, horrors, illusions, ghosts, spirits, etc.) or not to need the ones they might have (undead), or not to mind them being frozen (ice creatures, undead).

The reasons I suggested MR AND CR for Dom 2 were that:
1) PDF reported CR was not protecting, but it seems like it should, especially since in Dom 2, I expect it is the only way to specify that a creature should be immune to it, like an ice elemental or mechanical man.
2) MR does already seem to protect against it, or so it seemed to me when I tried it. So I assume that is the devs intent, and wouldn't argue with it. Also, it seems correct, as it is a Water-1 spell, even if it is Alt-6, so otherwise it would be seem to me a really cheap automatic hit.

As for comparing to lightning, shock resistance IS currently working there, and it also requires hitting with a missile effect and accuracy (doesn't frozen heart automatically hit?).

As for comparing to incinerate, well that too is a weenie auto-hit spell which I believe is resisted both by fire resistance and by MR. IIRC, it requires more fire magic, but does more damage. Seems in line with frozen heart being resisted by both MR and FR, to me.

PvK