How stuff scales

I'm currently working on getting some equations for threat-generation of a Bear as a function of a bunch of stats to see how strongly (or weakly) we scale with certain stats and how powerful some of the threat talents are. As an intermediate step, I had to determine how much damage each ability does with different amounts of AP. The effect of haste, hit, expertise, crit and ArP are well-documented or easy to deduce, but there wasn't much on how things scale with AP. So I made the Heroic Training Dummy my new best friend for an evening.

Methodology
Most of the testing was performed by testing the damage of an ability at different levels of AP by taking off gear. Most of the testing was done with my Moonkin spec, to prevent pesky talents from obscuring the raw data. Master Shapeshifter was clicked off, so there were no damage-increasing talents or buffs. I kept all gear with ArP off for the entire test, as it complicated calculations. This immediately meant that 2pc T10 was also not used, which was useful to keep Swipe and Lacerate testing clean.

At each level of AP, several attacks were made to determine the damage of the ability. Other than abilities that scale with the Druids weapon-damage (Maul, Mangle, auto-attack), all abilities have a fixed damage value rather than a damage range. A non-integer value means you can get both the integer below and the one above the precise damage value as outcome. Simply dividing the increase in damage by the increase in AP gives the scaling factor. For Maul and Mangle a larger number of attacks was needed. I took samples of about 40 hits and averaged the results.

Some results

• The initial hit from Lacerate is affected by armor, it is not buffed by the Mangle debuff, but it is affected by the 2pc T10 set-bonus.


• Faerie Fire (Feral) is a spell in all aspects: It uses your spellhit chance (17% chance to miss against a boss-mob without hit), your spellcrit chance and it crits for +50% damage rather than +100%. It deals Nature damage and is not affected by armor.


• Maul and Mangle do not scale as their tooltip would have you think. First of all, they seem to double-dip from Naturalist: The talent increases your normal melee damage by 10%, but Maul and Mangle scale with this melee damage and are increased by another 10%. This double-dipping, coupled with Savage Fury, makes the predicted scaling match what I observed from hitting the dummy. For Maul, there is a 10% discrepancy (the measured scaling is higher). In my result, I've taken the measured value. I still have to work out where this comes from.


• Maul and Mangle deal damage based on melee damage plus some bonus component. The bonus component in the tooltip does not seem to match the actual bonus component when hitting a target at all, no matter how I twist all the talented buffs that affect it. I will keep looking.

The numbers!
In the following table you'll find how much the damage from an ability increases when you add 100 AP. This includes any talents or debuffs that you can reasonable expect to be part of a Ferals spec or to be active on the boss: Savage Fury, Feral Instinct, Rend and Tear, Naturalist, Mangle/Trauma, a bleed effect, Blood Frenzy / Savage Combat and Arcane Empowerment / The Ret Paladin buff whose name I forgot.

Note that by 100 AP I mean a character screen difference of 100 AP. Talents (such as Protector of the Pack) and buffs (Trueshot Aura and such) increase the amount of AP you get from gear and buffs. I assume we're fighting a L83 boss-mob with appropriate armor value. Below you'll find the results for a fully sundered and Faerie Fired mob with 500 armor penetration rating (which is a typical value for a Druid gearing up with ilvl 264 T10 and similar offset items). Values are for non-crit attacks.

Ability	Damage increase from +100 AP
Auto-attack	15.3
Maul	34.1
Mangle	23.2
Faerie Fire (Feral)	15.5
Swipe	7.0
Swipe (2pc T10)	8.4
Lacerate hit	0.85
Lacerate hit (2pc T10)	1.02
Lacerate 5-stack tick	7.66
Lacerate 5-stack tick (2pc T10)	9.19

Conclusion
Well, the numbers speak for themselves, I'd say. Maul is easily the best-scaling attack, trailed by Mangle and FFF. The initial hit from Lacerate scales horribly with AP, which explains why Swipe takes over as filler-attack at pretty much any L80 gear-level.

This is just the start of my little research. It's all just damage, but what really matters is threat. I'll continue to work with these results, couple them with other stats, threat-modifiers, etc... Hopefully I'll find out what causes the strange discrepancies between the predicted and measured damage-values for Maul and Mangle in the mean time.