Along with Defense, every piece of armor has Elemental Resistances. These resistances determine how much damage you receive from elemental attacks. For every positive point of resistance for a certain element that you have, you will take 1% less damage from any attack with that element. Conversely, for every negative point of resistance for a certain element you have, you will take 1% more damage from any attack with that element. Considering which elements you are vulnerable to will help you to know which monsters and monster's attack to avoid. It should be noted that element resistances influence the effectiveness of blights related to the elements, for instance having a high fire resistance will cause Fireblight to last less. High resistance will also lessen the chances of, or outright prevent, Severe versions of each Blight.