Take note that a unique/boss mobs that spawns with ' Enchanted' will have an extra 75 resistance (to that one element), and a ' Magic Resistant' Unique/boss mob will gain 40 elemental resistance (fire, cold, and lightning).
(For PvP, this also is true against enemy players/minions). The lowest that a monster's resistance to any element can be lowered is to a combined total of -100. Monsters are considered 'immune' when their resistance to an element becomes 100 or greater.
