2.Defense, Crushing Blow, Melee Attacking, Glancing Blow, Special Attacks & Procs
Defense
Tank = a player who wants the enemy to attack him and not the others. Mobs in WoW are guided by "threat" system. Every player in combat has a threat rank, and mob will always try to attack the player highest on the threat rank (player with highest threat).
In order to tank properly, the tank must generate enough threat (aggro) to keep the enemy attacking him. He must also attain enough Hit Points to be able to withstand the attacks and/or enough Avoidance (Dodge, Parry, Block, to be Missed), to reduce the damage that he has to take.
1 point of Defense skill = +0.04% to be Missed, to Dodge, to Parry and to Block an enemy attack.
It also decreases the attacker's chance to Crit by 0.04%.
That means, +25 Defense skill = +1% to be Missed, to Dodge, Parry, Block an enemy attack, -1% to be Critically hit by an enemy.
By far, defense is the best stat any tank can get.
A level 60 player needs 425 Defense to be Crit immune versus a level 60 mob.
A level 60 player needs 440 Defense to be Crit immune versus a raid boss.
Crushing Blow
Crushing Blows can happen if a mob attacks a player with
base defense skill lower than level * 5.
Crushing Blow deals 1.5x base damage.
Only base defense is taken into account to determine the chance for a Crushing Blow, +Defense from gear does not count. Every point of defense skill missing will increase the mob's chance for a crushing blow by 2%.
Example: a level 60 warrior has 297 Defense skill, and he's fighting a level 60 mob. The mob's attack skill is 60 * 5 = 300, so the mob has 6% chance to make a Crushing Blow on our warrior.
The
only way to reduce chance of Crushing Blow is to gain combined chances to be missed, to dodge, to parry, and to block that high, that the Crushing Blow chance is pushed off the bottom end of your attacker's Attack Table.
Against a Raid Boss, all combined avoidance must add up to 102.4% to remove Crushing Blow from the Attack Table.
Melee Attacking
In a similar way to Defense, 1 point of Weapon skill will increase your chance to hit, crit and decrease the chance that your attack will be a glancing blow or that the target will dodge, parry, block your attack by 0.04%.
What weapon skill is used is dependant on the respective weapon type you are currently using.
Fist weapons and attacking with no weapon (or while disarmed) uses the Unarmed skill.
Glancing Blow
Glancing Blow is a type of hit that deals reduced damage and cannot crit.
Glancing Blows can be only white melee auto-attacks, special melee attacks and procs (Mortal Strike, Backstab, Seal of Command, ..) cannot be Glancing Blows.
Glancing blows do not occur against players, only against mobs.
The chance to perform a Glancing Blow is different for "melee" classes and for "non-melee" classes.
Melee classes - Warrior, Paladin, Rogue, Druid in Bear and Cat form - use this formula:
Code:
10% + (mob level * 5 - player's base weapon skill)*2%
Non-melee classes - Hunter, Shaman, Priest, Warlock, Mage, Druid in human, Travel, Aquatic and Moonkin form - have flat
60% chance to do Glancing Blows.
Base weapon skill is used, so
you cannot get rid of glancing blows.
Level 60 melee class will have 10% chance of glancing blows against a level 60 mob.
Level 60 melee class will have 30% chance of glancing blows against a level 62 mob.
Level 60 melee class will have 40% chance of glancing blows against a level 63 mob (raidboss).
Level 60 caster class will always have 60% chance of glancing blows against
ANY level mob.
Damage reduction of glancing blows varies based on the mob level and your weapon skill.
The damage reduction will be chosen as a random number value between low-end and high-end values for each attack.
Code:
Low-end caster classes: 0.6 - 0.05*(mob level * 5 - player weapon skill)
Low-end melee classes: 1.3 - 0.05*(mob level * 5 - player weapon skill)
The low-end value will never go below 0.01 or above 1.0.
High-end caster classes: 0.9 - 0.03*(mob level * 5 - player weapon skill)
High-end melee classes: 1.2 - 0.03*(mob level * 5 - player weapon skill)
The high-end will never go below 0.2 or above 1.0.
Example:
You are a warrior, you have 300 weapon skill, you're attacking a level 63 boss.
Code:
10% + (315 - 300) * 2% = 40% chance for glancing blow.
So you have a 40% chance of glancing blows vs. level 63 mob.
Damage reduction:
Code:
low-end value: 1.3 - 0.05*15 => 0.55
high-end value: 1.2 - 0.03*15 => 0.75
You can calculate average damage reduction:
(0.75 + 0.55) / 2 = 0.65
So for our example warrior, your glancing blows against the boss will deal 35% less damage on average.
Current weapon skill is used, so
you can decrease the damage reduction by raising your weapon skill from spells and items. With enough +weapon skill, all your glancing blows will hit just as hard as your normal hits.
A level 60 warrior with 300 weapon skill will deal 100%-100% damage against a level 60 mob. (average 0% reduction)
A level 60 warrior with 300 weapon skill will deal 80%-90% damage against a level 62 mob. (average 15% reduction)
A level 60 warrior with 300 weapon skill will deal 55%-75% damage against a level 63 mob (raidboss). (average 35% reduction)
A level 60 warrior with 305 weapon skill will deal 80%-90% damage against a level 63 mob (raidboss). (average 15% reduction)
A level 60 warrior with 309 or higher weapon skill will deal 100%-100% damage against a level 63 mob (raidboss). (average 0% reduction)
Source:
http://www.wowwiki.com/Weapon_skill?oldid=349298
Special Attacks, Extra attacks & Procs
Extra attacks are gained from talents or item chance on hit bonuses (Flurry Axe).
The shaman ability Windfury also adds Extra Attacks.
Any extra attack is treated as a separate normal auto-attack hit - it can miss, be dodged, parried, blocked, be a hit, a crit or a glancing blow (if attacking a mob).
Special attacks are usually seen as "Yellow numbers". These include abilities like Heroic Strike, Backstab, Seal of Command, Stormstrike, ... and physical proc abilities like Decapitate from
Halberd of Smiting.
They can miss, be dodged, parried, blocked, be a hit, a crit. Special attacks cannot be Glancing Blows or Crushing Blows.
The mechanic for resolving Special attacks is not properly documented. However it has been proven, that special attacks like Heroic Strike can be blocked and be a Crit at the same time (Blocked Critical hit).
A guy from Elitistjerks made a series of tests with Backstab, and came to conclusion that his critical hits with backstab are consistent => that would indicate the use of a two-roll system, same as spells.
Example: We have 2 level 60 warriors, both have maxed defense and weapon skills. Warrior A charges and attacks B with a Heroic Strike. As Warrior B is stunned from the Charge effect, he cannot Dodge, Parry or Block. Our warriors have both 15% chance to crit.
1st roll - if the Heroic hits (5% chance to miss, 95% chance to hit, block, dodge, parry is at 0% because of Charge stun)
2nd roll - if the Heroic crits. With a 15% critical chance, it's a simple
1-15 => Crit
16-100 = Hit
As explained above in the spells part, having a separate crit roll makes your crit rate more consistent and on average you would deal more critical hits.
Special autoattack cases:
Magic damage auto-attacks (for example, autoattack of a Fire Elemental deals fire damage) are also following the attack table rules, so you can Dodge, Parry them, they can Miss, but they
cannot be Blocked. In addition to the normal roll, hits, crushing blows and critical hits are also reduced by your corresponding magic Resistances (see above).
Magic damage melee special-attack (Seal of Command) are resolved in the same way as melee physical attacks. You can dodge, parry, block them, they can miss and be Critical hits. In addition, a resistance check is made with the corresponding resistance, same as with magic damage autoattacks.