Undead may be immune to freezing. You could try the survivor's Curse spell on them first to lower their resistances (can be cast repeatedly and quickly on the same target, so even level 1 is very effective), though the Freeze spell description doesn't mention resistance levels.
Frost on a weapon ignores resistances, so always triggers (to the point it can make combat very boring, at least for a melee character).
Last edited by Raze; 01/12/14 05:28 AM.
