Defense Defense ( also called " Defense rating " ) was an attribute that helped prevent physical damage by reducing the chance to be hit or critically hit . Additionally , it also increased block , dodge and parry . Mobs receive 0 . 1 % per point of defense . Mobs get an additional benefit from defense of Glancing Blows versus players . Each point of + Defense skill adds 0 . 04 % to the player ' s chance to be Miss ed , to Dodge , and to Parry , before diminishing returns are taken into account , and adds 0 . 04 % to the player ' s chance to Block with no diminishing returns . This means + 25 Defense will grant you an extra 1 % Miss , Parry , Dodge , and Block . The formula is constant across all classes . It further decreases the chance of receiving critical hits from any level attacker by 0 . 04 % per point that the target ' s Defense skill exceeds the attacker ' s Weapon Skill . Please note that a decrease in your chance to be hit ( like the tooltip says ) actually increases your chance to be missed . However , all of these chances are based on an opponent of equal level . The rating difference between the attacker ' s weapon skill and the defender ' s defense factors into the true chance for miss , parry , dodge , block , crushing blow , glancing blow , and critical hit . Note that while your tooltip chances to be dodged and parried will take diminishing returns into account , your tooltip decreased chance to be hit ( shown while hovering over your Defense on your character sheet ) will not . At 540 Defense , your actual chance to be missed by a level 80 mob is 9 . 288 % . Note that defense continues to be a valuable stat past its " cap , " unlike hit rating or expertise , because it still increases chances to dodge , block , parry and be missed . Reaching the soft cap of 540 defense skill ( not rating ) is considered mandatory for tank ing more difficult content , as a single critical hit from a boss can prove fatal . Critical Hits . See below for a more detailed discussion of Defense . Critical Hits are strikes by mobs against the player that deal twice the normal damage . The player ' s Defense and Resilience are both attributes that reduce the chance of an enemy critically striking . The chance to be critically hit is based on the difference between the attacker ' s weapon skill and the player ' s defense skill and resilience % . A mob has a weapon skill that is calculated by 5 x Level , and a player has a base defense that is 5 x Level . A player does not have any base resilience . Therefore a level 80 mob has 5x80 = 400 Weapon Skill . A level 80 player has a base defense of 5x80 = 400 Defense and no resilience . When an equal level mob is attacking a player , the mob has a 5 % chance to critically strike the player . For every level beyond the player , there is an additional 0 . 2 % chance for the mob to critically strike the player . Therefore a level 83 mob ( a raid boss ) attacking a level 80 player has a 5 % + ( 3 x 0 . 2 % ) = 5 . 6 % chance to critically strike the player . A player in the role of a tank for a raid boss must lower his or her chance of being critically struck by 5 . 6 % to avoid the possibility of taking 2x the damage from a single hit . This is where gear bonuses that augment resilience and defense are important . Each point of defense beyond the player ' s base reduces the chance to be critically struck by 0 . 04 % . Therefore , to become immune to critical hits dealt from a mob 3 levels higher , a player must have 5 . 6 % / ( 0 . 04 % per defense ) = 140 additional points in their defense skill to avoid a critical strike . Therefore a level 80 player with a base defense of 400 must have 400 + 140 = 540 Defense to become immune to critical hits through defense alone . Because a single critical hit from a raid boss can easily remove most , if not all , of its target ' s HP , becoming crit immune is far more important for tanks than anything else until they are immune ; even HP granted from high amounts of Stamina is not enough to mitigate a critical hit . However , resilience may also be used to lower the chance of being critically struck . There is no base resilience for players . Therefore a level 80 player with no additional defense points , will simply need 5 . 6 % resilience to become immune to critical hits dealt by a raid boss . Note that given a choice between PvP gear and actual tanking gear , the latter is far better because it provides additional use for tanks such as dodge and parry rating . For a level 70 player , gear that provides + 39 . 4 resilience rating will yield a 1 % resilience . And gear that provides 2 . 36 defense rating will increase the defense skill by 1 . For a level 80 player , gear that provides + 82 . 0 resilience rating will yield a 1 % resilience . And gear that provides 4 . 92 defense rating will increase the defense skill by 1 . See below for the formula used to derive defense skill from defense rating . See Resilience for a discussion on the formula to calculate % resilience obtained from resilience rating . Feral druids have Survival of the Fittest , which reduces the inbound crit rate by 6 % , making them naturally immune to melee critical hits in PvE . Reaching the crit cap . This script will show you how much defense rating you need at level 80 to be uncritable in Heroics and Raids . It collects your character ' s defense and resilience , then returns how many solid points of defense rating are needed to become uncritable . A need of 4 . 1 defense rating means you must equip 5 points of defense rating to be completely capped , so this script rounds up to the full amount required . Copy this into a macro or directly into chat ( Warrior , Paladin ) : Death Knights with Rune of the Stoneskin Gargoyle copy this : If the number is zero or negative , of course , you are uncritable . To determine whether you have reached the crit cap through Defense and Resilience , type the following into chat : Death Knights with Rune of the Stoneskin Gargoyle use this table instead : Or use this macro , to show up how much defense rating you need or how much you over - capped : If the number is 0 or negative , you are uncritable . If the number is above 0 , you require more defense or resilience vs level 73 bosses . Use this macro to determine whether you would be crit capped or not with specific resilience and defense rating numbers ( replace resilience = 0 ; and defense _ rating = 0 ; with your values ) . Death knights with Rune of the Stoneskin Gargoyle use this macro : Crushing Blows . Crushing blow s can happen if a mob attacks a player at least 4 levels lower . Because " boss " level mobs are considered to be level 83 they cannot deliver a crushing blow to any level 80 character whose defense skill is fully trained up to his level * 5 . Prior to patch 3 . 0 crushing blows affected players of at least 3 levels lower than the attacking mob so max - level characters ( typically the main tank ) could receive a crushing blow from a boss . Because of this change the rest of this section is mostly of historical interest . Only the player ' s " base " defense skill ( capped at 5 times the player ' s level , e . g . 350 for a level 70 player ) is taken into account to determine the base chance for a Crushing Blow , and therefore Defense Rating on gear does " not " directly decrease the chance for a Crushing Blow . Crushing Blows can be made less likely or entirely avoided by increasing avoidance stats such as Dodge or Parry or the player ' s Block Rating , as well as using certain skills , to the point where the player ' s combined Miss , Dodge , Parry , and Block chances against that specific attacker exceed 85 % . This is due to how the WoW combat roll system works , cf . Attack Table . In this regard , Defense Rating on gear " does " help against Crushing Blows . Refer to the Wiki sections Crushing blow and Uncrushability for an in - depth explanation of this mechanic . Dazed . If a mob hits a target from behind , and the target takes damage from the hit that isn ' t Absorb ed , there is a chance the player will be Dazed . The base chance for a level 30 + target to be dazed when hit from behind , if the mob ' s weapon skill is equal to the target ' s defense skill , is 20 % . This chance can get as low as 0 % if the target ' s defense is high enough , or as high as 40 % if the target ' s defense is low enough . If the target is below level 30 , its base chance to be dazed is less ; a level 10 target with fully trained defense skill only has a 7 % chance to be dazed when attacked from behind by a level 10 mob . Note that your defense skill is NOT level - capped for purposes of determining your chance to be dazed . It is possible to become undazeable while wearing tank plate gear . Patch 3 . 3 made level 1 - 5 characters immune to being dazed and level 6 - 10 characters less likely to be dazed . Changes in patch 2 . 0 . As of WoW 2 . 0 , additional defensive skill does not help avoid crushing blows . Instead of directly affecting Defense skill , items after patch 2 . 0 grant a bonus to Defense Rating ( DR ) . Skill bonuses are then calculated as follows : For a level 60 : 1 . 5 DR = 1 defense skill < br > For a level 70 : 2 . 36 DR = 1 defense skill < br > For a level 80 : 4 . 92 DR = 1 defense skill < br > It is important to note that for the sake of all indirect effects of Defense Skill ( dodge , block , parry , etc . ) , the game only considers Skill as an integer . That is , there is absolutely no difference between 10 Rating ( + 4 . 23 Skill ) and 11 Rating ( + 4 . 65 Skill ) , because they both yield only 4 integer points of Skill . However , there is a difference between 11 Rating ( + 4 . 65 Skill ) and 12 Rating ( + 5 . 07 Skill ) ; specifically , the difference is exactly 0 . 04 % dodge , block , parry , etc . At L70 you need 14 . 75 of defense rating to get 0 . 25 % increases to each of miss / dodge / parry and block for a total increase in avoidance of 1 % . At L60 this is 9 . 375 . Both may suffer small inaccuracies due to the above mentioned integer rounding . Cataclysm changes . Defense Rating , as a stat on gear , was removed with the release of patch 4 . 0 . 1 . All tank specs will rely on talents such as Survival of the Fittest for critical hit immunity . Currently this is implemented as Improved Blood Presence for Death Knight s ( as Blood Presence will become the tanking presence in cataclysm ) , Sanctuary for Paladin s , and Bastion of Defense for Warrior s in the talent trees .