Strategy: Maximizing Effective Life and Survivability
Your effective life (or EHP) is a measure of your overall survivability by taking into account all sources of damage mitigation. This can be calculated by converting each source of damage mitigation into an average percent damage reduction. This is simple to do for armor, resistances, and dodge. I try to include crowd control effects into this calculation to determine their effectiveness. Blinds and stuns are simple to incorporate based on the percent of time they are active. Effective life can be calculated as:
EHP = Life * (1/(1-TDR))
where TDR is your total damage reduction. To make calculations simpler, each source of damage reduction can be added separately:
EHP = Life * (1/(1-Source1)) * (1/(1-Source2)) * (1/(1-Source3)) * ….
Damage reduction from armor and resistances are calculated as follows:
%DR = ARMOR/(ARMOR + 50 * Mlvl)
%DR = RESISTANCE/(RESISTANCE+ 5 * Mlvl)
where Mlvl is the level of the monster attacking you. Note that each point of strength provides +1 armor, and each point of intelligence provides +0.1 resistance. This means that one point of strength is exactly equal to one point of intelligence with respect to your EHP. One is no more beneficial than the other.
Dexterity will add directly to your chance to dodge. However this relationship is diminishing and has breakpoints. From 0 to 100, each point will add 0.1% chance to dodge. From 101 to 500 dexterity, each additional point will add 0.025% chance to dodge. The full table can be seen below:
Each point of Vitality will add 10HP to your base life.
From analyzing the rate of change of EHP with respect to each of the character attributes (strength, dexterity, intelligence, vitality), adding more vitality will generally be the best way to increase your EHP. However, keeping vitality low, and pumping damage reduction will result in your healing abilities being more effective. In general, it is recommended to maximize your primary attribute and vitality.