User:Timgurto/Magic effective health

Originally posted 8/31/08

Last week I was playing around with my gear sets and decided to apply the "effective health" theory (health modified by armor) to resistances. The approach is similar, but the important difference is that while armor suffers diminishing returns (in terms of direct % mitigation, not survivability... a little complicated, but not worth worrying too much about), resistances offer a constant mitigation from 0% at 0 to 75% at 365 (for 73 mobs).

TL;DR
1 resistance ~= 40 health.

Definition
Magic effective health is the equivalent health you have against an unmitigated magical attack.

Example: You have 10k health, and a spell would hit for 5k. At 0 resistance, you have 10k EH against this attack. At 365 resistance, The spells do a quarter of their normal damage on average, and thus you have 40k EH. This is equivalent to having 40k hp with 0 resistance.

Similarities with armor EH
This difference is the same as it is with armor EH though; while the EH is the same, healing is easier with the resistance (or armor) rather than the health, since heals apply to health only. If 10k health expands to 40k EH, then a 5k heal will heal 20k of that EH. if a tank had 40k health but no resistance, that same 5k heal would only heal for 5k of that EH. This is the same reason why balancing armor and stamina is so important on physical fights.

Findings

 * When you have high health but low resistance, resistance is much more useful than additional health
 * Vice versa
 * On average (and this applies to most situations), 1 resistance ~= 40 health.

What does this mean?
Basically, if you're gearing for a resistance fight and your chief concerns are resistance and health, you'd be hard pressed to find any piece with enough stamina that it'd be preferable to a green protection suffix. In a lot of cases the stamina alone on these pieces is comparable.

Differences between resistances and armor
There is an important note to consider, though: resistances do not act the same way as armor. The two differences are:
 * resistance doesn't suffer from diminishing returns; already mentioned, and not worth worrying too much about
 * resistances don't mitigate damage the same way that armor does.

Explanation
Armor mitigation acts as a constant percentage (eg. 59%), which can be viewed by mouse-overing your armor value in the character pane. All incoming physical attacks are reduced by this value (eg. a 10k unmitigated hit would become 4.1k). With resistances it's different. All spells hit with one of five degrees of power (0%, 25, 50, 75, 100%. A 5k spell could hit for 0, or 1.25k, or 5k. On the other hand, your resistance offers a similar percentage to armor mitigation. How does this work? Basically, these randomly selected degrees will average out to become that percentage value. So, if you're resist-capped and your percentage is 75%, most incoming spells will hit at 0%, 25% or 50% of their normal strength, but there will be the occasional 100%. Fun!

How to gear against elementals

 * 1) Hit the resistance cap! 365 against bosses*
 * 2) Maximize health
 * 3) Armor is useless
 * 4) Block chance is useless. Block value is useful only for warrior threat; I'll have to talk to Durabo or Holy about implications for pallies
 * 5) On elementals like Hydross, don't sacrifice too much avoidance for health. Avoidance (miss, dodge, parry, not block) still applies.
 * 6) On elementals, be uncrittable. Uncrushable is impossible with available gear; these mobs will likely not crush.

Of course, if someone is hitting you normally and at the same time you're taking magic damage (eg. Corehounds, some SSC Boglords, etc.) it's generally a good idea to ignore resistances. Don't take my word on this for every fight, but you can't be expected to gear for resistance while being fully capable of physical tanking - blocking, armor, and usually crushings come into play against any physical boss. The magic damage in question usually won't be too spiky in nature, and healing it shouldn't cause any major problems. This is all from my experience; there are the occasional fights that don't subscribe to this formula though. On the way to Curator, for example, you'll find pulls consisting of one arcane elemental and half a dozen mana wyrms. The wyrms hit like pansies (unless you use mana), but the elemental deals quite fierce arcane elemental damage. On those pulls I generally gear in favor of arcane resistance, since the wyrms would hardly do any damage if I had no armor and no avoidance or block.