Mitigation vs Hard HP
Are there any numbers anywhere about how much mitigation is equal to a certain amount of actual health?

X mitigation is equivalent to X% additional of your total health in effective health against that damage type.

Tl;DR version:
Ideal: 3k hp 150 MR 150 Armour 5k HP 300 MR 300 Armour 2k HP 100 MR 100 Armour 
Easiest Explanation:
Every 100 resist or armor you have, you gain "Effective HP" equal to your current HP. 
The formula for damage reduction is
armor / (100 + armor) = reduction This is the same for armor and magic resist. You can do your own math. 
1 armor = 1% more effective hp against physical attacks.
1 mr = 1% more effective hp against magical attacks. The 1% is drawn from your base HP pool. Easy as pie. Also, there are more things to take notice of, not just raw stats. You gotta think cost effectiveness. 
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