Devastate damage formula

From wow.incgamers.com

Author : Lavine , http://beta.worldofwarcraft.com/thread.html?topicId=800094&sid=2

With a new 41 point protection tree talent up and no recorded data on it's workings so far, I decided to smash up a random orc in every possible way in order to find it all out. Since I doubt everyone wants to read it all, I'll keep it short and add my notes to the bottom.

Devastate(Rank 2) reads: An instant weapon attack that causes 50% of weapon damage plus 25 and additional threat for each application of Sunder Armor on the target. In addition, this attack will renew the duration of the Sunder Armor effect.

- How does Devastate damage work? Where does it's 25 damage, instant attack power bonus and weapon damage come in?

Devastate deals 50% of your unmodified weapon damage, plus
Devastate deals 50% of Attackpower/14*Normalizedweaponspeedmodifier, plus
Devastate deals 25 damage for each Sunder Armor on the target (max 125).

The matching formula is:
0,5 * ( Weapon Damage + Attack Power / 14 * Normalized Weapon Speed ) + 25 * #(Sunder Armor)

Devastate is an instant weapon attack that activates normal weapon procs and is affected by normal armor values. Devastate can be missed, dodged, parried, blocked and can crit, just like any other attack. Devastate can only be used with One-Handed Weapons.

Surely it's possible a mistake is made somewhere throughout the experiments, but so long as no one has a better theory the fool that is shouting loudest is correct, hah! I copied my notes down below and made them a bit more userfriendly.

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- How does the 25 innate damage on rank 2 work?
Test by applying sunder armor one at a time and checking damage difference after adding reduced damage by armor.
Decide armor value-reduction by mob.

Test-target for all experiments, lvl 55 Servant of Sevine, Sunder Armor (SA) rank 5, Devastate Rank 2
Reduction at 0 Sunder Armor is (107-67)/107 = 37% Getting 100% damage for 0 sunders is /0,63
On a similar approach:
Reduction at 1 Sunder Armor is (107-73)/107 = 32% and getting 100% damage is /0,68
Reduction at 2 Sunder Armor is (107-77)/107 = 28% and getting 100% damage is /0,72
Reduction at 3 Sunder Armor is (107-82)/107 = 23% and getting 100% damage is /0,77
Reduction at 4 Sunder Armor is (107-88)/107 = 18% and getting 100% damage is /0,82
Reduction at 5 Sunder Armor is (107-93)/107 = 13% and getting 100% damage is /0,87

Applying Devastate(rank 2)

Cutlass(range 10-20)
SA:0 Dam:47 No reduction: 47/0,63 = 74 Dv0-Dv0: 0
SA:1 Dam:67 No reduction: 67/0,68 = 99 Dv1-Dv0: 25
SA:2 Dam:88 No reduction: 88/0,72 = 122 Dv2-Dv1: 23
SA:3 Dam:112 No reduction: 112/0,77 = 145 Dv3-Dv2: 23
SA:4 Dam:138 No reduction: 138/0,82 = 168 Dv4-Dv3: 23
SA:5 Dam:168 No reduction: 168/0,87 = 193 Dv5-Dv4: 25

Quel'Serrar(range 84-126)
SA:0 Dam:76 No reduction: 76/0,63 = 121 Dv0-Dv0: 0
SA:1 Dam:98 No reduction: 98/0,68 = 144 Dv1-Dv0: 23
SA:2 Dam:118 No reduction: 118/0,72 = 164 Dv2-Dv1: 20
SA:3 Dam:143 No reduction: 143/0,77 = 186 Dv3-Dv2: 22
SA:4 Dam:170 No reduction: 170/0,82 = 207 Dv4-Dv3: 21
SA:5 Dam:205 No reduction: 205/0,87 = 235 Dv5-Dv4: 28

Since numbers were rounded up an down several times during the calculation and the input data was retrieved manually and often based on estimates, the number 25 (which is being looked for) is not solidly present. Regardless of those minor flaws and the huge randomness involved in the Quel'Serrar weapon range, the lineair +25dmg trend is evident.

The +25 damage stacks at every Sunder Armor that's applied on the target, eventually leading to +125 damage at 5 sunders.

- How does the attack power apply?
Test by performing same experiment with only Battle Shout rank 7 [232 AP] (on/off) as variable. Recalculate numbers due to damage reduction.
Compare with existing AP/14*(normalized weapon speed) rule for instant attacks.

SA:0 Dam:48 Dam+AP:60 Diff: 12 No red: 12/0,63 = 19
SA:1 Dam:66 Dam+AP:79 Diff: 13 No red: 13/0,68 = 19
SA:2 Dam:86 Dam+AP:100 Diff: 14 No red: 14/0,72 = 19
SA:3 Dam:112 Dam+AP:127 Diff: 15 No red: 15/0,77 = 19
SA:4 Dam:136 Dam+AP:152 Diff: 16 No red: 16/0,82 = 20
SA:5 Dam:166 Dam+AP:183 Diff: 17 No red: 17/0,87 = 20

232 AP gives a steady 19,5 damage

Comparing with existing instant attack AP formula: AP / 14 * 2.4(sword)

Expected damage is 232 / 14 * 2.4 = 39,77. The 19.5 is close to half of that.

This suggests that the 50% in the Devastate attack description also applies to attack power. Or rather it suggests that instant weapon damage is calculated from AP modified weapon damage, as opposed to most formulas circulating on the net, where AP bonus is added separately. Admittedly, it's easier to read and deduct in that format.

- How does the weapon damage work?
Test by substracting all known points of damage from total damage and compare with weapon damage range.

Using above examples. 777 attack power at 10-20 weapon damage range.
(48 / 0.63) - (0.5 * 777 / 14 * 2.4) - (0 * 25) = 76 - 67 - 0 = 9
(66 / 0.68) - (0.5 * 777 / 14 * 2.4) - (1 * 25) = 97 - 67 - 25 = 5
(86 / 0.72) - (0.5 * 777 / 14 * 2.4) - (2 * 25) = 119 - 67 - 50 = 2
(112 / 0.77) - (0.5 * 777 / 14 * 2.4) - (3 * 25) = 145 - 67 - 75 = 3
(136 / 0.82) - (0.5 * 777 / 14 * 2.4) - (4 * 25) = 166 - 67 - 100 = -1
(166 / 0.87) - (0.5 * 777 / 14 * 2.4) - (5 * 25) = 191 - 67 - 125 = -1


Similar with Quel'Serrar 84-126 damage range
(76 / 0.63) - (0.5 * 777 / 14 * 2.4) - (0 * 25) = 121 - 67 - 0 = 54
(98 / 0.68) - (0.5 * 777 / 14 * 2.4) - (1 * 25) = 144 - 67 - 25 = 52
(118 / 0.72) - (0.5 * 777 / 14 * 2.4) - (2 * 25) = 164 - 67 - 50 = 47
(143 / 0.77) - (0.5 * 777 / 14 * 2.4) - (3 * 25) = 186 - 67 - 75 = 48
(170 / 0.82) - (0.5 * 777 / 14 * 2.4) - (4 * 25) = 207 - 67 - 100 = 40
(205 / 0.87) - (0.5 * 777 / 14 * 2.4) - (5 * 25) = 235 - 67 - 125 = 43

The 0 Sunder armor value shows the correct half weapon damage. These results show a gradual decrease in damage from the weapon itself when Sunders are applied. Rather then taking this up as a conclusion, I believe that the gradual decrease is caused by an improper 25 innate Devastate damage or caused by unidentified human errors. Having tested most of this in defensive stance with One Handed Weapon Specialisation, it might be possible that the 25 damage part is affected by -10% def stance modifier, but not the +10% One Handed Weapon Specialisation, bringing all values up to a normal rate. 2-3 damage per sunder remain missing in these experiments, as long as proof of an error in the Devastate formula is not given.

From this we can conclude the Devastate Damage Formula
0,5 * ( Weapon Damage + Attack Power / 14 * Normalized Weapon Speed ) + 25 * #(Sunder Armor) = Damage