Resist Cold increases the Paladin's cold resist. It also gives a passive bonus. For every two hard points invested into Cold Resist, the Paladin gets a passive +1 to maximum cold resist that is active at all times regardless of whether the aura is turned on or not. So with 20 points invested (not counting + skill items), the maximum cold resist of the Paladin would be 85 instead of the regular 75.
Lore[]
The splendor of absolute devotion is all the warmth and comfort a Paladin requires. Embraced deep within the shelter of this aura, the faithful need never fear the frost. [1]
References[]
↑Diablo II Manual, page 83. Blizzard Entertainment, 2000.