Base damage done = (Base Weapon damage + Enchanted Weapon damage) * (Power / 100 + Weapon Passive% bonus / 100 + %Skill bonuses / 100) + Attack bonuses + Skill damage bonus
* Base weapon damage is the weapon damage itself on the tooltip (before enchants).
* Enchanted weapon bonus is from +'ing your weapon, and it's a static addition. (so, 40 for a +10 bow)
* Power is your power stat at the top of the screen, most physical classes use 100, or 110, or higher if flying.
* Weapon Passive % bonus is your weapon mastery skill you get. It depends on the skill. For me, I tested staff mastery @ 25 (15%), and Archery Mastery @ 25 (4%). For others you'd have to do math yourself. Staff Mastery @ L10 (10%). Mace Mastery @ L10 (27%), etc.
* % Skill bonuses are for abilities like Rage Spell for Chanters, and Devotion for Assassins and Rangers.
* Attack bonuses are static bonuses like Victory mantra, Attack mana stones, attack stats on weapons.
* Skill damage bonus is the amount of damage added because you're using a skill, such as Surprise Attack. Most numbers are baked into the tooltip number, but it's easy to figure out for surprise attack, since the bonus damage is conditional, and written elsewhere. If you're not using a skill, it's 0.
The damage will be further reduced by Pdef (depending on the mob/player), and PvP Bonuses. I haven't tested those out, but they have been documented. (Pdef / 10 for damage reduction, and -50% for PvP)
If the damage crits, a crit multiplier is added. For the weapons I've tested (staff/bow), the crit multiplier is 1.7 (not 1.8 as others have said for weapons).
Crit multipliers that I tested.
Dagger - 2.3x Sword - 2.2x Mace - 2.0x Greatsword - 1.8x * Polearm - 1.8x * Bow - 1.7x Staff - 1.7x
* Tests done by kr0sis a few posts down.
Finally for auto attacks, if a weapon is multi-strike it can do more damage as well. My testing with staves showed about 1:1:1 ratio doing extra 0, 1, or 2 hits. Extra hits do 10% damage each, and rounded down based on the base damage done. So, auto attacks for staves on average do about 10% more damage.
Lastly, numbers are floored (rounded down) at the very end for auto-attacks. My crit rating was too low to get a complete set of numbers to see how flooring occurred on skill crits.
I tested skill damage with Hallowed Strike II lvl 9 (+125 damage), and Stunning Shot I lvl 9 (+245 damage).
Stunning shot is unique that it has the property to sometimes do double base damage (about 30%~1/3 of the time). Since defense reduction is calculated once, you do a bit more than 2x the base damage, and that number can crit too, it can end up doing a lot of damage. Hence, since it can break 2k damage at even level 30, it's very useful against high defense targets, such as gigantic chests.
Since I was using 2hd weapons, my KD rate for staves was about 22% over all crits.
Skill tooltip damage: (Even though it shows on the tooltip, the damage doesn't match, and uses the formula above, but this is for reference anyways:
Tooltip damage = Base skill damage + Base Weapon damage * ((Power + 100) / 2) / 100
* Base skill damage is how much the skill does at its without the weapon damage added on. For tooltips, it's the min or max value that's used.
* Base weapon damage is your unenchanted damage. (Enchanted bonus damage doesn't show on the tooltip)
* Power is your power stat.
If you need to find base skill damage, you can reverse the formula above, or check it barehanded. With fists, the min~max is 16~20 (if you have 100 power), 17~21 (if you have >100 power), and 15~19 (if you have <100 power). Aionarmory and other websites with melee skill info always uses the 100 power with fists to show their stats, but it also depends on the skill, since it usually refers to level 0, instead of level 1. (You can always check in game though).
Don't ask my why for 110 Power you only see a 5% increase in the weapon damage part, it's just how I got the tooltip to match up.
If anyone wants me to explain a bit on how I came to the conclusions I will, there was quite a bit of data involved.
But the training dummy in Poeta reduces damage done to it by 25, so I guess it has 250 Pdef according to gerbator's calculations.
Edit: Added a crit multiplier table based on additional tests I did.
Edit: Added crit multipliers from kr0sis' post a few posts down.
This post has been edited by Cel: 22 December 2009 - 04:10 PM