The following is current, accurate mechanical theory related to Threat. If you're looking for the conclusions and advice rather than the math, check
Single & Multi Target Threat. Pulling & Holding Aggro (100/110/130 Rule)
Code:
Tank (Baseline) _____________________ 100%
Melee Range Aggro Gain ______________ 110%
Ranged Aggro Gain ___________________ 130%
The above chart represents the balance of when a player will pull aggro from the tank. To get aggro, a player in melee range must exceed the total threat of the current player with aggro by 10%. If the player is at a range, they would have to produce 30% more threat to fully gain aggro.
This has some important implications. First, it gives you breathing room to miss a few attacks and not instantly lose aggro -- that seems to be the purpose of the 10% rule. Second, it means that ranged classes take a heavy risk by moving into melee range with a large amount of threat built up -- the mob will instantly change targets to a ranged target who moves into melee. Third, this means that tank switching can be difficult in some cases.
Taunt Abilities
Warrior Taunt immediately places you at 100% aggro of whoever the highest-Threat player is on the target list for that creature. It also bypasses the 10% rule and does not require you build immediate threat. When tanking, it may be helpful to remember that you can let any player you want build Threat for you on a mob -- all you have to do is Taunt the mob to get everything they worked for and make the mob yours. This is also a good argument for Improved Taunt.
One important note about Threat gained from Taunt is that you will only gain the Threat of the current target of your creature. For instance, a ranged class such as a Mage may have 120% of your accumulated Threat, but due to the 100/110/130 rule has not pulled aggro. You would not receive the Threat bonus from that Mage for using your Taunt prior to him actually being targeted by the creature. If a creature is applying a Secondary or Random-Secondary ability where he temporarily changes targets to someone else -- disregarding his normal Threat table -- you will not gain the Threat of the player he is targeting.
Taunt, as well as Mocking Blow and Challenging Shout, also force your target to attack you through a debuff placed on the creature. This debuff can be helpful when the creature may be in danger of immediately moving to or harming another party or raid member. For instance, some mobs will randomly Intercept nearby players, wiping or diminishing their Threat list. A well-timed Taunt or Mocking Blow can cause a creature that may otherwise not return to you to immediately do so. Challenging Shout can be useful as a six-second buffer for an AOE class to safely damaging several nearby targets at once; it can also be useful in temporarily capturing the attention of one or more creatures that may otherwise kill a nearby player.
Aside from the debuff, Mocking Blow and Challenging Shout are dissimilar to Taunt and will not give you a Threat gain in relation to another player. Mocking Blow and Challenging Shout are six second targetting debuffs; Taunt is three.
Threat Multipliers by Class
The following chart shows multipliers to Threat values that affect the amount of Threat players produce.
Code:
Ability Multipliers Percent Multiplier
Defensive Stance / Bear Form ________ 130% (1.3) Multiplicative
Defiance / Feral Instinct ___________ 115% (1.15) Multiplicative
Fury Stance (Imp Berserker) _________ 71% (0.71) Multiplicative
Battle Stance _______________________ 80% (0.8) Multiplicative
Rogue / Cat Form Druid ______________ 71% (0.71) Multiplicative
Blessing of Salvation _______________ 70% (0.7) Multiplicative
Tranquil Air Totem __________________ 80% (0.8) Multiplicative
Druid (Subtlety) ____________________ 80% (0.8) Multiplicative
Priest (Silent Resolve) _____________ 80% (0.8) Multiplicative
Mage (Frost Channelling) ____________ 90% (0.9) Multiplicative
Mage (Burning Soul) _________________ 90% (0.9) Multiplicative
Mage (Arcane Subtlety) ______________ 60% (0.6) Multiplicative
Warlock (Destructive Reach) _________ 90% (0.9) Multiplicative
Warlock (Imp. Drain Soul) ___________ 90% (0.9) Multiplicative
Innate Threat & Ability Threat Values
Many Warrior abilities are built around the concept of Innate, or hidden, Threat values. What this means is that abilities which neither deal Damage or Healing produces Threat on the targeted creature when used. Innate Threat never replaces Threat produced from damage; in many cases, such as with Shield Slam, Devastate, Heroic Strike and Revenge, the Damage portion of the ability produces Threat in addition to the innate value.
The following chart gives detailed Innate Threat values for abilities at Level 70:
Code:
Shield Slam _________________________ 307
Revenge _____________________________ 200
Devastate ___________________________ 176 (Special, Read Below)
Sunder Armor ________________________ 301
Heroic Strike _______________________ 196
Shield Bash _________________________ 230
Cleave ______________________________ 130 (Split)
Mocking Blow ________________________ 290
Demoralizing Shout __________________ 56 (Split)
Battleshout _________________________ 69 (Split)
Commanding Shout ____________________ 68 (Split)
Disarm_______________________________ 104
Hamstring ___________________________ 181
Whirlwind ____________________ 100% Damage (Unaffected by Stance Multiplier)
Execute ______________________ 100% Damage (Unaffected by Stance Multiplier)
Thunderclap __________________ 175% Damage
Spell Reflect ________________ 100% Damage
Piercing Howl and Concussion Blow do not generate Threat.
Sunder Armor continues to generate the same threat even after five applications.
When Threat is split as indicated above, that means it is either divided by the number of mobs affected or by the number of creatures aware of your presence. This is determined by whether the ability directly affects the creature or not. For instance, the Threat from Demoralizing Shout shout would only be split by the creatures it directly hits; however, the Threat from Commanding Shout would be split among all creatures engaged with your character.
Devastate Threat Per Current Sunder Armor Application
0: 119
1: 134
2: 148
3: 162
4: 176
All of the above will also add 301 Sunder Armor Threat. After the fifth application, it will continue to provide 176 Threat but will no longer apply Sunder Armor. Damage will always be calculated as Threat in addition to the above, and will increase with each application of Sunder Armor.
Damage as Threat
All damage is Threat; not all Threat is damage. Any increase in damage will be a direct increase in Threat. Threat from damage scales in specific ways.
The most obvious scaling can be seen in Shield Slam, which becomes stronger as a Warrior collects standard tanking gear with Shield Block Value.
Devastate and Normal attacks both scale from Attack Power. Though improvements in this area are generally less perceptible, they make up a significant portion of your overall threat. Devastate and Normal attacks also benefit from party and raid buffs.
Heroic Strike and Devastate scale based on Weapon Speed. However, getting faster weapons for Heroic Strike is much better in terms of net gain; Devastate is Normalized, meaning your Attack Power bonus is based on a 2.4 Speed weapon, whereas Heroic Strike is not affected by Normalization, and the fastest weapons will produce the best possible results.
Critical Strikes & Effective Abilities
Critical Strikes have no unique impact on Threat. The extra Threat generated from a Critical Strike is strictly from the damage produced; Innate Threat is not affected.
The Threat on abilities such as Hamstring Shield Bash are not affected by whether the effect is successful or not unless the target is fully immune to the ability. For instance, Hamstring will deal 181 Threat regardless of whether the target is slowed. Even if the target is immune to slowing, the ability will still gain the 181 Threat bonus since Hamstring also causes damage -- the ability is at least functionally operational so the Threat is awarded.
