Kenco ' s research on threat This is a copy - paste of the EU repost of Kenco ' s ( ) original post from the official forums from January 2006 with his research on Aggro / Threat levels called " Some Threat Values and Formulas " . Some Threat Values and Formulas . It ' s often said that we will never be able to work out the way threat and hate lists and mobs ' AI works , because it ' s too complicated and unknowable , that we ' ll only ever have crude approximations and guesses . I ' ve conducted some decent , rigorous tests , and i have what i believe is a good list of hate values and explanations of gaining and losing aggro and the behaviour of taunt . I am also able to debunk a few myths about how threat works . Definitions . We define " aggro " to be who the mob is attacking . We define " threat " to be a numeric value that each mob has towards each player on its hate list . Note , as we shall soon see , even for a normal mob , the target who has aggro is not necessarily the player on its threat list with the most threat . We define arbitrarily that 1 point of unmodified damage gives 1 point of threat . Gaining aggro on a mob . Suppose a mob is attacking player 1 . In order for the mob to switch to player 2 , he must do more than just exceed the threat of player 1 . If he is in melee range of the mob , he will draw aggro when he exceeds 110 % of player 1 ' s threat . If he is outside melee range of the mob , he will draw aggro when he exceeds 130 % of player 1 ' s threat . E . g . mob is attacking player x . x does 100 damage to mob , then stops . Player y starts hitting the mob . The mob will start attacking y when y does over 110 damage . Proof : this is easy to demonstrate . Get two players both doing autoattack on a mob ( not warriors or rogues ; we ' ll see later they complicate things ) . Have player 1 do a certain amount of damage , then stop . Have player 2 keep attacking till he gets aggro . You have an upper and lower bound on the threat required to get aggro - 1 attack before he got aggro was not enough , but the attack that he got aggro was at least enough . With low damage attacks ( i . e . fists only ) , you will get a very good value of 10 % . Testing for the non - melee range value is the same . Just replace it with a low damage ability such as a low level wand . If player 2 has exceeded 110 % threat but not 130 % threat , they will draw aggro immediately if they do a threat - generating ability within melee range of the mob , but proximity alone will not cause the mob to shift to them . This is only a description of the normal mob targeting . Obviously there are mobs who will attack secondary targets with special abilities , ignoring their current threat / aggro . Threat modifiers from Warrior Stances . In Battle Stance and Berserker Stance , all threat from a Warrior is multiplied by 80 % . In defensive stance , the multiplier is 130 % . With Defiance , it is 145 % . Proof : a simple modification of the above proof . Get a warrior to do , say , 1000 damage in defensive stance , without defiance . Get a non - warrior to take aggro with white damage . You will find it does not happen before 1430 damage . The warrior ' s 1000 damage caused 1300 threat in defensive stance , and the 10 % barrier means you need more than 1430 to gain aggro . Threat does not decay . Threat never , ever decays . Here is test data . Warrior does 83 damage on mob in battle stance , gains aggro . From above , we know it will take more than 83 * 0 . 8 * 1 . 1 = 73 . 04 threat to gain aggro . Warrior waits for 5 minutes getting beat on . Then mage starts attacking slowly . Mage does 73 damage , but does not gain aggro ! Mage does another 2 damage , and does gain aggro . From the warrior ' s initial hit to losing aggro , the time taken was 496 seconds . As an upper bound , assume maximal threat decay . i . e . the mage only needed 73 . 040000001 threat to gain aggro . Then the warrior ' s threat had decayed to 66 . 36363636 , from 66 . 4 . This means he went down to 99 . 945 % threat in 496 seconds . At this maximal rate of hate decay , the time taken for the warrior ' s threat to decay to 90 % of the original value would be 26 . 5 hours . In fact , if a warrior logged in as soon as the server came online after the weekly reset and hit a mob , his threat would not decay to 50 % before the server reset next week . I think this is enough to rule out threat decay . Threat values for some warrior abilities . the following list is not exhaustive , but includes all the major tanking abilities . Note : the following values are given in raw terms . In reality the warrior must have either a 1 . 3 or 0 . 8 or 1 . 45 modifier on these , depending on his stance and talents . Note : * All abilities do not include threat generated by their damage . This will be discussed more later . Sunder : 261 ( 260 . 95 - 261 . 15 ) Heroic Strike * : 145 ( 143 . 9 - 148 . 8 ) Revenge * : 315 ( 313 . 9 - 318 . 3 ) Revenge Stun : 25 ( 23 . 4 - 29 . 1 ) Shield Bash * : 180 ( 175 . 4 - 180 . 3 ) Shield Slam * : ? ? 250 ( estimated from Cop ' s data . More on that later ) Shield Block : 0 ( 0 - 0 . Can be higher - more on this later ) Thunder Clap * : 130 ( 126 . 9 - 134 . 8 ) Demo Shout : 43 ( 42 . 8 - 43 . 8 ) Note that debuffs associated with abilities are not connected to the threat they generate . Demoralizing shout generates the same amount of threat whether the debuff is on or not . Sunder armor generates the same threat after 5 debuffs are on as when there are 0 . Healing , " you gain x _ _ _ " , etc . Each point of healing , when completely unmodified by talents , gives 0 . 5 threat . Replace the proof for ( 2 ) by the second person only healing . Note : overhealing doesn ' t count , only the actual amount healed . This is easy to demonstrate . Abilities that put " you gain x mana " in the combat log give 0 . 5 threat per point gained ; life is the same . Examples would be drinking potions , but not natural regen , or the Shaman ' s mana spring totem . Abilities that put " you gain x rage " in the combat log give 5 threat per point gained . However , this is not modified by warrior stance . Such abilities include bloodrage , improved blocking talent , unbridled wrath , and 5 / 8 Might . Like healing , these only give threat if you are below the maximum . Explaining Cop ' s 4 . 0 damage to heal ratio . Cop stated that in his tests , each point of damage by the warrior took approximately 4 points of healing by the priest , for the priest to get aggro . Here ' s how : Warrior in defensive stance , with defiance : 1 . 45 multiplier Gaining aggro from Warrior : 1 . 1 multiplier Priest with discipline : 80 % threat Healing : each point gives 0 . 5 threat Together , 1 . 45 * 1 . 1 / 0 . 8 / 0 . 5 = 3 . 9875 . Pretty darn close to 4 . Threat from pulling ? There is no threat associated with pulling . The smallest amounts of threat we could generate drew aggro from a body pull , no matter how long we waited after the pull . However , there are advantages to having the tank pull , as explained in the next secion . Taunt . Casting taunt causes three effects . A ) The warrior is given as much threat as the person who currently has the mob ' s aggro . Obviously if the warrior has aggro , this will do nothing . Also , this effect will not lower the warriors threat . For example , if player 1 has 100 threat and aggro , a warrior could have 105 but not aggro ; after taunt he would still be on 105 threat . B ) The mob recalculates its actual aggro target . If the warrior was on the mob ' s hatelist before the original aggro target , the mob ' s actual aggro target will switch to the warrior . Otherwise , the mob will remember it ' s original target . C ) The normal taunt debuff . The mob is forced to attack the warrior , even if the warrior is not its actual aggro target . The threat that the warrior gains from ( A ) is permanent , regardless of the outcome of ( B ) . Note that it will not necessarily give the warrior the equal highest threat on the mob . If player 1 has 100 threat and aggro , Player 2 has 109 threat but not aggro , and the warrior has 0 threat , then the warrior is given 100 threat , not 109 , so he could easily lose aggro to Player 2 after taunting . Implications . Note this section is just my opinion . a ) Let the tank pull ! Then he will be first on all the mobs ' hatelists , and his taunts will always return aggro to him . b ) Given that targets at range will only draw aggro when they have more than 130 % of the mob ' s target ' s current threat , it ' s important for a tank to keep the mobs well away from the casters . If a healer does draw aggro and you taunt it off him , make sure you also move it away . c ) Heroic Strike should not be used as a primary threat ability . Suppose you are tanking a level 62 mob . Let ' s give him 8 , 000 ac raw , and even assume he has 5 sunders stacked , for 5750 final ac , so he will take 48 . 89 % of damage . A 15 % crit rate is balanced by the 10 % penalty to damage in defensive stance , and a 10 % chance of a glancing blow chance for 50 % damage . Then you can expect the 138 damage from Heroic Strike to contribute 67 . 5 damage on average , for a total of 212 unmodified threat . This is still only 82 % of the threat a sunder would give . Even with a 1 . 3 speed weapon , you will still do 94 % the threat of sunder per time interval . Best practice is to spam sunder , and use HS in between to soak up excess rage . d ) Revenge ftw . You can expect to do about 345 unmodified threat with Revenge , including damage , against the mob in the example above , which is exceptional for the low rage cost , even throwing in 10 for a shield block . However , there is a rage cost of shield block , in that you will block more attacks , so take less damage , so gain less rage from damage . Two blocks for 180 damage and you can say goodbye to another 4 rage . e ) Demo Shout ftl . Demoralising shout does one sixth the threat of a sunder . Even spammed in defensive stance with defiance , you ' re doing no more threat than 42dps on each mob . Besides picking up whelps in Onyxia and tanking panthers in the Panther boss encounter in ZG , i can ' t see a compelling reason to use this . f ) Shield Slam ftl . Given the 6 second cooldown , there is no improvement in threat per second by using shield slam . With shield slam : 3 sunders and 1 shield slam every 6 seconds . About 212 threat per second , unmodified . With the 30 rage from the shield slam you can cast 1 sunder and about 1 . 2 heroic strikes , assuming you have the talents ( which you would with any shield slam build ) , and are losing 3 rage per Heroic Strike from lost white damage rage ( i . e . assuming 90 modified damage per hit ) . The 4 sunders and 1 . 2 heroic strikes every 6 seconds gives about 215 threat per second . The only improvement is if you are spamming both sunder and HS , and want even more threat . Suppose we have a 2 . 0 speed weapon , HS spam and sunder spam . That ' s about 280 unmodified tps . Changing one sunder for a shield slam gives us 318 unmodified . However , the same effect would be achieved by changing to a 1 . 4 speed weapon and casting HS more often . And these values aren ' t taking into account autoattack damage , which makes the margins comparatively smaller . g ) There ' s no amazing super secret randomised blizzard aggro algorithm . The concepts are simple and the values can be fitted with nice numbers . Even formulas for threat - reducing knockbacks can conceivably be worked out , if threat values are carefully monitored . Well , i hope some of you are still awake , and are feeling somewhat enlightened . And if you skipped to the bottom , i can ' t exactly blame you after my essay above . See also . : EJ forum