Defense
From WoWWiki
Defense is a skill that helps prevent physical damage by reducing the chance to be hit or critically hit. Additionally, it also increases 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 chance to be Missed, to Block, to Dodge and to Parry for players. 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.
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[edit] Critical Hits
Quick Facts:
- Critical Hit immunity for a level 70 player against a raid boss occurs at 490 Defense and requires a defense rating of 330.4 from gear to achieve. Most classes have talents that increase the defense skill or reduce critical hit chance so less than 330.4 defense rating from gear will be needed for critical hit immunity.
- Critical Hit immunity for a level 70 player against a raid boss can also be achieved by a Resilience of 5.6% and requires a resilience rating of 220.64 to achieve.
- The critical hit % reduction from Defense and Resilience % may be combined to reduce the chance of being critically hit by a raid boss by 5.6% making the player immune to critical hits.
See below for a detailed discussion of Defense.
Critical Hits are strikes or spells 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 70 mob has 5x70=350 Weapon Skill. A level 70 player has a base defense of 5x70=350 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 73 mob (a raid boss) attacking a level 70 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 70 player with a base defense of 350 must have 350 + 140 = 490 Defense to become immune to critical hits through defense alone.
However, resilience may also be used to lower the chance of being critically struck. There is no base resilience for players. Each percentage point of resilience reduces the chance to be critically struck by 1%. Therefore a level 70 player with no additional defense points, will simply need 5.6% resilience to become immune to critical hits dealt by a raid boss.
Gear no longer gives points purely to the defense skill or to the resilience %. Rather, gear gives points to defense rating and resilience rating, which are converted to points in defense and resilience based on the player's level. 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. 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 can take a talent that reduces the inbound crit rate by 3%, placing the values at 400 and 415 defense skill, respectively, at level 70. Due to the new talent Survival of the Fittest Druids need only 65 additional defense or 2.6% resilience to negate all critical hits from skull mobs. This is achieved, in other words, by a defense of 365 at level 60 or defense of 415 at level 70. This talent provides great relief to Druid Tanks since Defense Leather gear is scarce.
To determine whether you have reached the crit cap through Defense and Resilience, type the following into chat:
Druids:
/script DEFAULT_CHAT_FRAME:AddMessage(2.6-(GetCombatRatingBonus(CR_DEFENSE_SKILL)*.04+GetCombatRatingBonus(CR_CRIT_TAKEN_MELEE)),1,0.5,0)
Everyone else:
/script DEFAULT_CHAT_FRAME:AddMessage(5.6-((20+GetCombatRatingBonus(CR_DEFENSE_SKILL))*.04+GetCombatRatingBonus(CR_CRIT_TAKEN_MELEE)),1,0.5,0)
Note: Change the number 20 in this formula to reflect the amount of defense you are getting from the Anticipation talent.
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.
There have been reported occasional critical hits reported from crit immune tanks. There can be various reasons for this. This page will explain more: Satrina about Critical Hits and Crushing Blows
[edit] Crushing Blows
Crushing blows can happen if a mob attacks a player at least 3 levels lower. Commonly this would be a "boss" level mob attacking the main tank.
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.
[edit] 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) instead. Skill bonuses are then calculated as follows:
For a level 60 : 1.5 DR = 1 defense skill
For a level 70 : 2.36 DR = 2 41/112 DR = 1 defense skill
or, put another way, 1 Defense Rating is worth 0.423 Defense Skill.
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.
[edit] Enhancements
[edit] Enchantments
- Enchant Bracer - Major Defense
- Enchant Bracer - Deflection
- Enchant Bracer - Lesser Deflection
- Enchant Bracer - Minor Deflection
[edit] Flasks
- Flask of Fortification: Increases maximum health by 500 and defense rating by 10 for 120 min.
- Shattrath Flask of Fortification: Increases maximum health by 500 and defense rating by 10 for 120 min.
[edit] Gems
| Color | Name | Effect(s) | |
|---|---|---|---|
 Meta
| [Tenacious Earthstorm Diamond] | +12 Defense | Chance to Restore Health on hit |
| [Eternal Earthstorm Diamond] | +12 Defense | +10% Shield Block Value | |
 Yellow
| [Facet of Eternity] | +12 Defense | |
| [Thick Lionseye] | +10 Defense | ||
| [Thick Dawnstone] | +8 Defense | ||
| [Thick Golden Draenite] | +6 Defense | ||
| [Thick Amber] | +4 Defense | ||
 Orange
| [Champion's Fire Opal] | +4 Defense | +5 Strength |
| [Glimmering Fire Opal] | +4 Defense | +5 Parry Rating | |
| [Glistening Fire Opal] | +5 Defense | +4 Agility | |
| [Stalwart Fire Opal] | +5 Defense | +4 Dodge Rating | |
 Green
| [Effulgent Chrysoprase] | +5 Defense | 2 Mana every 5 sec |
| [Enduring Seaspray Emerald] | +5 Defense | +7 Stamina | |
| [Enduring Chrysoprase] | +5 Defense | +6 Stamina | |
| [Enduring Talasite] | +4 Defense | +6 Stamina | |
| [Enduring Deep Peridot] | +3 Defense | +4 Stamina | |
[edit] See also
| Attack table | |
|---|---|
| Spell | Resist • Reflect • Spell critical strike • Spell hit • Spell penetration |
| Melee | Hit • Critical strike • Crushing blow • Glancing blow • Expertise |
| Defense and damage mitigation | Resilience • Resistance • Absorb • Deflect • Miss • Block • Dodge • Parry |
| Related | Immune • Evade |
