Uncrushability A tank was considered uncrushable when they were immune to crushing blows delivered by raid bosses . In order to do this , the attacking mob ' s attack table must have been filled completely with other attack results that take " precedence " over Crushing Blows . Against an opponent 3 levels higher than the tank — Boss mobs are treated as being 3 levels higher than their targets — all combined avoidance need to add up to 102 . 4 % . However , changes in Wrath of the Lich King made this largely a non - factor for raids . It still applies for mobs 4 levels or higher above a player character . In Wrath of the Lich King . As of Wrath of the Lich King , the crushing blows mechanism have been changed . Now only mob four level higher than you can deal crushing blows . Therefore , uncrushability is irrelevant for raids in Wrath of the Lich King and the avoidance stats below are no longer necessary . Calculating combined avoidance . In order to discover a tank ' s total combined avoidance , one adds together the following values : Note that Druid tanks cannot block or parry at all ; becoming Uncrushable is nearly impossible for a druid . There have been some sets made which push total avoidance ( miss + dodge ) over 102 . 4 % for a druid , thereby making them uncrushable by pushing all attacks off the table . However , attaining these sets requires a huge amount of effort and access to extremely late end - game gear , and are considered a novelty and by no means a requirement for a serious druid tank . Active Uncrushability . Even for those tank classes that can parry and block , most still cannot reach this 102 . 4 % value without using some sort of special ability . For warriors , uncrushability is easy to attain using Shield Block , as the 100 % bonus to blocking will make these numbers add up to 102 . 4 % very easily . However , this ability only lasts for 10 seconds , with a 60 second cooldown ( which can be reduced to 40 seconds through talents ) . For Paladins , it is more difficult , as Holy Shield will add only 30 % to this . ( Redoubt cannot be relied upon to proc when the paladin needs it . ) However , if you know where to look for gear and which pieces of gear to use , it is not difficult to achieve uncrushability with only Holy Shield within two to three weeks of level 70 . Most paladins will equip the Libram of Repentance , as this adds a further 42 block rating , or 5 . 33 % block chance , while Holy Shield is active . See for other useful tips about paladin tanking gear . See also Karazhan Entry Set , which is a sample uncrushable tanking set that consists only of pre - Kara " non - boss drop " gear . Passive Uncrushability . A tank is " passively uncrushable " when he or she cannot be crushed , even when not using either Shield Block or Holy Shield . Achieving this level of avoidance requires an enormous amount of avoidance stats , usually by stacking block rating and defense . It is now obtainable through a combination of Karazhan , ZA and Tier 5 gear , although at the expense of significant amount of stamina . Passive Uncrushability is especially helpful to warriors , as the two charges from Shield Block are eaten up very quickly in many situations . Moreover , passive uncrushability helps the threat of warriors , as they free up rage that otherwise would have been spent on Shield Block . The Warrior talent Shield Specialization makes this easier to attain for warriors , as it gives them an extra 5 % block . It ' s less useful to paladins , as their eight charges from Holy Shield are used up much more rarely during boss fight , and trash mobs during AOE tanking cannot crush . It does not harm the threat of paladins , as they can still use Holy Shield skill anyway even if the extra blocking is not needed . Stated in reverse , because Holy Shield is still needed for threat purposes , the stat sacrifices required for passive uncrushability are not attractive for tankadins .