Effective Health Calculator
Effective health in World of Warcraft is the amount of damage you can absorb before dying. It is a function of your health and armor, and ignores avoidance. Effective health is primarily a factor when tanking high-end raid content and can have a significant impact on decisions made about gear selection for these encounters.
How do I use this?
The calculator is designed to give you a side-by-side comparison of two different armor sets, where one or more items are different. Effective health is your protection against spike damage (higher is better). "Damage Taken" indicates how much healing you'll need (theoretically) over the course of an encounter (lower is better).
If you simulate mob damage, Hits Before Death and Overkill can help you make some gear decisions. Low Hits Before Death score and high Overkill value? Find a way to increase your effective health. High Hits Before Death and moderate overkill? Drop some effective health and pick up avoidance instead. Overkill can also tell you whether your Flask of Stoneblood is making a difference. Real overkill values from the combat log are better than simulated values. Just click "What Happened to Me?"
About the Calculator
The calculator above was written as a response to discussions regarding optimizing effective health to increase tank surivability during the Gormok the Impaler phase of the Northrend Beasts encounter in ToC 25 Heroic.
The discussion raised the issue of the value of armor compared to stamina. Specifically, the discussion sought to compare the Glyph of Indomitability to pure stamina trinkets like the Bubbling Brightbrew Charm, Royal Seal of King Llane, and Juggernaut's Vitality. Also of note was a comparison between a Signified Ring of Binding and a Band of the Traitor King socketed with +30 stamina.
Theorycraft
Research on the issue of armor vs. stamina lead to the following conclusions: Armor is not subject to diminishing returns with regards to time-to-live. Also, as your stamina pool grows larger, armor becomes increasingly more valuable. Finally, additional armor augments your total health score, so armor / stamina items can't be compared in a vaccuum. Given currently-available itemization in 3.2.2, armor eventually becomes more valuable than stamina for increasing effective health in melee-heavy encounters.
At lower gear / health levels, raw stamina is more valuable. The full effect of armor is most noticeable on druid tanks and raid-buffed tanks with health levels in excess of 45,000 hitpoints, though the exact break-point will depend on your health:armor ratio, as well as buffs and the availability of equipment. Also note that armor is only effective against physical damage, and encounters with heavy spell damage will see an increased benefit from additional stamina.
What About Avoidance?
Effective Health is not the only thing a tank needs to pay attention to. Avoidance and threat generation are obviously also very important aspects of tanking. The crux of the effective health issue is that certain encounters subject tanks to tremendous amounts of spike damage (upwards of 150,000 unmitigated damage in milliseconds), and it is not possible to prevail in these encounters without increasing effective health above the spike threshold.
All tanking classes have abilities that can be used to increase effective health, such as Last Stand and Divine Protection, but these come with long cooldowns. Generally speaking, a tank with higher effective health takes damage in a more consistent fashion (making healing easier) and has better survivability, thereby improving the odds of completing any given encounter.
Additional Reading
If you'd like to read more on the subject, check out this article regarding "diminishing returns" on armor from Satrina or this article on effective health from TankSpot.
Feedback
Questions, comments, or corrections regarding the calculator? Shoot an e-mail to contact@facerollsyndicate.com.