With my freshly enchanted amulet and ring I had finally achieved magic immunity. The dream of standing in front of a dragons breath without being affected was in my grasp. I began to conjure a fire atronach just to feel its pathetic fireballs bounce off me. As I attacked it, scenarios with mages and dragons filled my mind. I could no longer be affected by them. As the small fireball exploded so to did all my hopes and dreams, I took damage, I was not immune.
The reason is that unlike oblivion in skyrim magical damage reductions are capped at 85%. This means that complete immunity to magic is impossible but it is possible to get close by using a combination of magic and elemental resists. Having 85% magic resistance and 85% fire resistance will reduce fire damage by 97.75%. I have tested all this in game and also found similar results here. The game uses the following formula:
damage taken = (damage incoming * ( 1 – magic resist) ) * ( 1 – elemental resist )
This means that by maxing magic, fire, ice and lightning resist you will almost be immune to magic damage. This can be achieve fairly easily by using enchantment and alchemy. That said, in practice you are not going to want to use all your enchant slots on resistance so ill demonstrate a build that allows you to have a spell school that doesn’t use magic and has resistance to 2 elements (even with the alchemy/enchantment exploits I don’t think it is possible to have 3).
25 – Breton Race Trait
25 – Lord Stone
20 – Alteration Magic Resistance (4 perks)
15 – Agent of Mara Quest
Elemental Resistance (Armour Set):
42 ice | 42 fire – Boots
42 ice | 42 fire OR 42 ice | 42 shock – Amulet (if you have 2 you can swap between fire or lightning)
42 shock | 28% MR – Ring
28% MR | free slot – Helmet
28% MR | 17% MR and Mana Regen – Body
*MR is a magic reduction in a school of your choice
The required skills for this are:
Enchantment: level 100, 8 perks (5 x Enchanter, Insightful Enchanter, Corpus Enchanter, Extra Effect)
Alchemy: level 100, 7 perks (5 x Alchemist, Physician, Benefactor) This is assuming you don’t use the Alchemy/Enchantment exploit with the exploit you can get 43 on each element and hit 85%.
For a character that does not use alchemy 7 perks may be too much, if you only wanted to get magic resistance without focusing on a spell school with 100 alchemy and no perks you can get 78% elemental resistance which means you would have 95.6% magic damage reduction.
Now if you wanted to have the most powerful anti magic tank you could also add the atronach skills which give magic absorb:
30 – Alteration Atronach (3 perks assuming you have the magic resist perks)
50 – Atronach Stone which also reduces mana regeneration by 50% and adds 50 magicka
These are applied before the magic resists so you have an 80% chance to completely block any magic attack which would bring the maximum achievable damage reduction to 99.55%. In practice, absorb doesn’t work as well against dragons but resist does so you should aim to build resist first and absorb as a luxury on top. After putting everything together my dream of having magic immunity is only crushed by 0.45%.