I am attempting to do a few things with this post:
- I want to cover what an AP Debuff is
- How it differs from a Slow Debuff
- Provide developer views on the effects and importance of said debuffs
- Discuss who can bring it & how it can be improved
- The math behind it
Question: What is a AP Debuff?
Answer: An Attack Power Debuff is an effect which reduces the NPC's Attack Power by a given amount. This results in less damage being applied against a tanks armor value, resulting in increased mitigation on Melee (and some special) attacks.
Question: So it's like Thunderclap, Icy Touch, etc?
Answer: No, Attack Speed Slow debuffs alter the rate of incoming damage, not the actual amount per hit. Simply, the mob is going to hit you just as hard as if the Thunderclap had never been applied, it will simply deal this damage slower. Conversely, an AP debuff results in less damage per hit, but doesn't alter the rate the damage is applied. You will still be hit at full speed rate without a slow effect, just each individual hit will be smaller.
Thus for maximum survivability, a raid will want to ensure a AP Debuff and a Melee Slow are both active and present on a target for the duration of the encounter.
Taken from the Warrior Q&A:
Question: Demoralizing shout (AP Debuffs) tends to have a very minimal impact in most situations, are there plans to improve this ability?
Answer: I think by “most situations” you must mean “PvP.” Demo Shout has a massive benefit against raid bosses. It’s probably 20% less damage from a typical boss and literally like 50% against say Thorim’s Unbalancing Strike. However, removing 400 attack power from a Feral druid with 9000 attack power, or a Shadow priest who doesn’t care about attack power at all is of much more limited use. Monsters and players use pretty different combat formulae (which is one of the weird things about the old design of say Vindication). We would like Demo Shout to be more useful in PvP, at least against characters who rely on attack power.
Taken from Re: WTB AP debuff so I can do my job
Question: Shouldn't Death Knights get a AP Debuff like the other 3 Tanks so we can do our job?
Answer: We made it much, much easier to get those buffs and debuffs than ever before. But you still can't say make a raid of 10 rogues (or even a tank, a healer and 8 rogues) and then say "bring the player, not the class" should let you be as competitive as a raid comp that maximizes buff / debuff potential.
There are very few mandatory buffs, and we made it even easier to get those that affect tank survivability, such as Fort, Gift and Kings.
You don't need an AP debuff to be successful, and if you really want one, there are plenty of ways to get it.
Taken from Re: WTB AP debuff so I can do my job
Question: Doesn't this unfairly hinder 10 man raids?
Answer: We don't assume an AP debuff for a 10-player raid, though it is certainly nice to have. We assume you have it in a 25-player raid. We make some assumptions about the most important buffs and debuffs for larger raids, particularly those trying the heroic / hard mode content. Those include things like Replenishment, Fort, Kings, Gift, Bloodlust / Heroism, CoE, the AP debuff, Sunder Armor, the attack speed debuff, and maybe Scorch and a few others. Even in those cases you don't need every buff / debuff the game offers and even if you're missing one of the big ones, you can overcome that with enough skill (or gear). The bosses don't do an instant berserk if they detect you are missing Demo Shout. Yes, it will be harder without. Hard modes are for guilds capable of doing hard modes. Normal modes are for almost everyone.
Fortunately, Demo Shout isn't hard to get. No, you can't just randomly assemble any 10 characters and have a strong raid comp. But you certainly have a lot more flexibility in how you assemble your groups than in the BC content, and the proof of that is in the enormous diversity of raids that are beating the encounters.
Question: Doesn't the second comment conflict with the first?
Answer: Not totally, It is however possible to overcome a lack of one debuff assuming your raid has the skill or desire to offset it. There are several specs which are non-tanks which can apply a AP Debuff even if they suffer a DPS loss. You would have to have a very exact raid balance in 10 man format including duplicates of some classes to not have access to a AP Debuff.
This does not mean I am in agreement with Death Knights lacking a AP debuff, it does however enforce that a Raid is a collaborative effort and DPS are expected at least by the Developers to chip in and help out if necessary to ensure raid success.
Who Can Bring a AP Debuff:
There are currently 12 viable specs capable of applying a AP Debuff, we will discuss this by class and list any talent point requirements if required.
Hunters:
Hunters have the strongest base effect via their pets once the pet is Level 80. They require no talent point investment, but the effect is fairly short lasting at 10 seconds. A common misconceptions is the Hunter has to be a certain spec. This is false. Any Hunter can use the pet family which provides the debuff.
So lets look at the most likely possibly issue.
The current popular Hunter pet for raiding is a Wolf. Wolves belong to the Ferocity tree, and have a special ability to increase the Hunter and Pets Attack Power by 320 for 20 seconds every 40 seconds. This 320 AP buff is really what they are giving up. The Carrion Bird which apply the AP debuff is also of the Ferocity family, and so can use an identical talent tree to the Wolf.
If you can convince the Hunter in your raid to get a bird, you can save them some time and direct them to Dragonblight. These birds are level 72, but will auto level to 75 once tamed. They are currently the highest level tamable Carrion Bird, which means the hunter will have to level the pet the other 5 levels on their own.
The effect at 80 is the following:
Demoralizing Screech
Blasts a single enemy for 85-129 damage and lowers the melee attack power of all enemies in melee range by 574. Effect lasts 10 sec.
The thing is is the debuff is short lasting, but is an AE effect much like a Warrior's shout. This allows the bird to fill a similar role in a pinch and doesn't require any alteration of talent points, but does use a stable slot and is a slight DPS loss to a Hunter.
Warlocks:
Warlocks are the second class in terms of raw untalented power. The DPS loss for a Warlock is steeper then that of a Hunter, due to the fact they often would prefer to use a different Curse. The base effect can be applied by any spec.
That said, occasionally you have to make due the if the tanks are -really- getting smacked around asking the Warlock to use the following may help.
Curse of Weakness (Rank 9)
10% of Base Mana
30 yd range
Instant cast
Target's melee attack power is reduced by 478 and armor is reduced by 5% for 2 min. Only one Curse per Warlock can be active on any one target.
This effect is stronger then the Base ability of a Warrior or Druid at level 80, and the Curse is obtained at level 71. The issue here is if you want a maximum powered effect for max reduction, the Warlock would have to invest 7 Talent points in the Affliction and get 2/2 Curse of Weakness.
Doing this results in the Curse being on par with all the fulled powered AP debuffs in the game currently. For a rough estimate at how strong the Curse is without talent points I'd venture around a 12% reduction in incoming melee damage. It should be noted that the Curse of Weakness is the longest lasting AP debuff currently in game.
Paladins:
Paladins have no base AP Debuff ability, without investing in talents, they can not gain this ability.
Paladins gain Vindication (-574 AP at level 80 at 2 Point investment) by spending 12 points in the Retribution tree. Vindication is applied passively during combat and can hit a max of 4 or so targets with either Hammer of the Righteous (If Prot) or Divine Storm (if Ret). Holy Paladins can not be expected to reasonably apply Vindication.
The effect however does only last 10 seconds which requires considerable attention by the Paladin to maintain as any target switching or ability which prevent the paladin from landing several attacks in a row can result in the Debuff dropping off.
It is generally considered easier for Paladin tanks to apply their own debuff then it is for Warriors or Druids due to Vindication's passive application and low talent cost. However Paladins lack the ability to apply the debuff to a large group of NPCs like the later two tanks can.
Warriors:
All 3 Specs of Warrior can apply Demoralizing Shout. It is generally considered easier for Fury Warriors to apply it as they invest points in the Tree which increases it's power by default. Arms or Protection Warriors can apply the effect also however, but may not be able to provide a fully powered shout as easily as Fury can.
Demoralizing Shout
Instant
10 Rage
Reduces the melee attack power of all enemies within 10 yards by 411 for 30 sec.
This ability without any talents increasing it's effectiveness is roughly equivalent to 10%-12% or so reduction on NPC's damage variant on if the NPC is trash or a boss. Warriors with 10 points invested in the Fury tree however, can increase it's power to rival all of the previous effects, resulting in maximum reduction at -575 AP.
Warriors can increase this ability in two ways:
Booming Voice: For 2 Talents in the top tier of Fury, warriors will increase the radius of Demoralizing Shout to 15 yards and the duration of the effect to 45 seconds. This results in a wider application area and reduces the amount of time spent refreshing the ability saving both rage and global cooldowns.
Improved Demoralizing Shout: is a 5 Point talent in the second tier which increases the power of the attack reduction by 8%/16%/24%/32%/40%. At max reduction (and 5 point investment) this altered Demo Shout to be -575 AP reduction on all NPC's in Range.
The obvious advantage here is a Protection Warrior can apply this on demand to any number of targets in range provided they have Rage. They can also choose to forgo extra TPS and invest in additional mitigation from the debuff.
For illustrative purposes the rough 5% the Improved Talent provides would roughly be the difference in tanking between tanking in full gear and tanking without a chest plate and leg armor. Thus it really comes down to how well each individual warrior can mange without points in talents like Deep Wounds weather or not they'd take the Improved Talent.
Feral Bear Druids:
While all druids have access to Bear Form, and thus Demoralizing Roar, it is only considered feasible to be applied by a Bear Tank due to the length of the debuff and the costs of shifting continuously.
Demoralizing Roar (Rank 8)
10 Rage
Instant
Requires Bear Form, Dire Bear Form
The druid roars, decreasing nearby enemies' melee attack power by 408. Lasts 30 sec.
Notes: The Range is 10 Yards, and the ability is obtained at level 77. It will increase in power 1 point per level till level 80, resulting in -411 (equivalent to the Warrior ability).
Likewise, the Druid Feral tree has an talent to increase it's power.
Feral Aggression is in the first Tier of the feral tree, and has a 5 point cost. Each point will increase the power of Demo Roar by 8%/16%/24%/32%/40% resulting in a max reduction at 5 points of -575.
Differences between Druid and Warrior:
Prior to Level 70 the Druid ability was considerably less then the Warrior one. This will only equal out to even post level 70. Additionally, the Druid lacks any ability to increase the range or duration of Demo Roar.
So for Ease of Clarity we'll break this down into AE and Single Debuffs:
AE AP Debuff:
Demoralizing Screech
Demoralizing Shout
Demoralizing Roar
Single (or Limited) Debuff:
Vindication
Curse of Weakness.

