I am really interested in the actual calculations behind damage, how stats increase, avoidance calculations (e.g., miss chance, dodge, etc.), and so on.
How are these calculated? Is Diablo based on a role-playing system (such as GURP) whose calculations are publicly available?
Best Answer
There is no comprehensive list of rules yet, but the fine folks at MMO Mechanics have spaded a list of formulas to start off.
Player Life
Life when player level < 35 = 36 + 4 × Level + 10 × Vitality
Life when player level ≥ 35 = (level - 25) × Vitality
Damage
Damage on Character Sheet = (1 + passive skill boosts)*(Weapon DPS + ((minimum damage bonus + maximum damage bonus)/2)Attack Speed)(Weapon Damage Multipliers)(Attack Speed / Weapon Speed)(1 + ( crit% * crit damage %))*( 1 + (main stat / 100))
Spell Damage Modifier = (1 + passive skill boosts)(Weapon Damage + (minimum damage bonus + maximum damage bonus) / 2)(1 + (main stat / 100))
Defense
Total damage reduction = 1 - ((1 - DR from Armor) × (1 - DR from Resistance) × (1 - other DR))
Physical damage reduction = Armor / (50 × Monster Level + Armor)
Elemental damage reduction = Resistance / (5 × Monster Level + Resistance)
Offense
APS (attacks per second) = base weapon APS × (1 + dual wield bonus + other attack speed bonuses)
Experience
Group Mechanics
Normal
Nightmare
Hell
Inferno