I'm trying to theorycraft and test around various mechanics and interactions to see what skills, stats, and items are really contributing value to survivability. I see a lot of resources around dealing damage and wondering if someone has already done the heavy lifting on the other side of the coin for mitigating damage.
I have some specific questions, like:
Does %melee or %ranged reduction get applied before or after Force Armor? If most melee attacks at high GRs are going to get capped by Force Armor (assuming sufficient health pool), and %melee gets applied before Force Armor, this would diminish the value of String of Ears.
Are certain types of damage reduction pooled (e.g. additive)? Seems like different amounts of %melee and %ranged from different sources are impaired in similar fashion to CDR. What about buffs like Safe Passage?
Blur - is this a true damage reduction after all mitigation? If I take it off, am I actually going to start taking 20% more damage?
And also some general gameplay questions like:
How best to balance mitigation and healing, and what forms of healing give the most value for stat slots? I was working with next to no healing for most of 2.1, relying on Templar heals, globes, and potion and between those cooldowns or availability being starved for regeneration and playing at risk. I've got a fair amount of Life per Second now (18,000). Life on Hit seems fairly suspect, doesn't proc from Hydra as I understand it. Proc rate for Blizzard-Apocalypse is 1.3% IIRC, but hits lots of targets so heals do come through and might be worth having?
Plus anything else, tips / tricks, little-known gems around survivability?
Ranged/melee damage reduction, just like any other reduction, is applied before Forced Armor. If this wasn't the case, only HP would matter for Force Armor, and people would run around with a million HP and absolutely zero mitigation, which obviously is not desired by Blizzard.
Same types are additive, the rest is multiplicative. It looks like this: (armor reduction) * (all resistance reduction) * (melee or ranged damage reduction) * (optional: elite damage reduction) * (damage reduction from other sources, such as skills). Within those categories damage reduction is additive (cf. the lower increase in armor mitigation the more you stack of it), but it seems that this is not always the case for the last category; for example, Ignore Pain from a barbarian might stack multiplicatively with Blur, I've heard. This is easy to test if you have a barb in group and see if your toughness straight out doubles when he activates Ignore Pain or if there's only an increase of about 40-45% in toughness for you (make sure you have Blur selected and no Glass Canon selected).
As you can see from aforementioned formula, there's no "before" or "after", they're all different mitigation sources and therefore multiplicative, and multiplicative operations are commutative (a*b = b*a). Blur applies the full 20% additional mitigation to all the other mitigation sources (armor, allres, elite, melee/ranged, ...).
Balancing healing and mitigation probably depends on your playstyle and spec. Does your spec allow for LoH (some skills don't proc LoH)? Do you have high attack speed or low attack speed (no proc coefficients anymore, but IAS now matters for LoH)? Alternatively, you can stack high life regen or high health globe bonus. There's no one way to do it right (or wrong), I've seen all different things. Not sure what wizards in particular go for at this point, but it's probably save to say that no wizard in endgame sacrifices and stats for LoH/life regen as primary affixes on gear. Damage > mitigation > everything else.
Three maybe useful links:
A list of all elite affixes and which of them can be mitigated through elite/melee/ranged damage reduction.
I have some specific questions, like: