A debuff is the contrary of a buff. It is an effect that while it persists hampers the target in some way. Among other effects, debuffs frequently lower attributes, hinder the effectiveness of the target's actions, or cause damage over time.
Sometimes the term debuff is also used to describe the act of removing buffs on hostile targets, but it is better to refer to such an action as a dispel or cure after the common spells that remove such effects. Another popular name for removing debuffs is decurse.
A good example for a multi-function debuff is the Hunter's Mark. All attackers on that target gain increased ranged attack power; additionally the target cannot hide from the Hunter, no matter if they stealth, turn invisible, or morph into beast form. Hunter's Mark, being in the Arcane school, is removable with Cloak of Shadows and other skills and talents which remove magical debuffs.
Debuffs come in many varieties and most of them are race/class specific spells or abilities.
In Vanilla WoW the number of debuffs that may be applied to a creature at one time was originally 8, but was later increased to 16 in patch 1.7.0. Raiders welcomed the increase. However, given that raids field up to 40 players, doubling the limit hardly resolved the issue of important debuffs getting pushed off. Important buffs such as Sunder Armor or Judgement of Wisdom that helped large segments of the raid could be replaced by a Hunter's weak Serpent Sting DOT.
There was still controversy about why the limit was there in the first place. An official stated on the official forums:
"World of Warcraft doesn't currently support an unlimited number of debuffs, but such is something that could be possible through change to our code. However, such code change would take valuable programmer time, which is best used elsewhere for the time being."
Late in vanilla, Blizzard began systematically assigning values to debuffs so that a weaker debuff could not displace a stronger one. The system was announced in February 2006, but it didn't begin to affect the live game until patch 1.11.0 in June.
Blizzard announced that the limit would increase to 40 in The Burning Crusade and in later expansions the debuff limit was removed completely.
Examples of Debuffs
- Warlock: Curse of the Elements
- Hunter: Scorpid Sting
- Druids: Faerie Fire
- Warrior: Demoralizing Shout
- Rogue: Wound Poison
- Priest: Shadow Weaving
A list of types of debuffs, the classes that can remove them and the earliest level that class gains the ability.
- Poison: Paladin (8), Druid (14), Shaman (16),
- Disease: Paladin (8), Shaman (22), Priest (22)
- Magic: Priest (18), Warlock [Felhunter] (30), Paladin (42)
- Curse: Mage (18), Druid (24), Shaman (Resto talent, 40)
Examples of Abilities that Cure or Dispel
- Druid: Remove Curse, Abolish Poison
- Mage: Remove Curse
- Paladin: Cleanse (Cures Disease, Poison and Magic)
- Priest: Dispel Magic, Abolish Disease
- Shaman: Cure Toxins, Cleanse Spirit
Some debuffs are not classified in any way, and as such can not be dispelled by any class. There are some exceptions to this - some Bleed effects, which are unclassified, can be cured by using a Luffa or the Dwarven racial ability Stoneform. Also, Paladins can dispel nearly any debuff on themselves by using Divine Shield, as can Mages by using Ice Block.
- Armor reduction
- Minor (stacks with major)
- / : -5%, also prevents stealth.
- : Wasp ability, -5%, also prevents stealth.
- : -5%, also reduces melee attack power, each warlock can only have one active curse per target.
- Major (stacks with minor)
- : Worm (Exotic Hunter pet) ability, -10%, stacks twice.
- : -4% per application, stacks up to 5 times.
- : -4% per application, stacks up to 5 times.
- Attack speed lowering (melee)
- Attack power reduction (melee only)
- : -408 @ max rank (~571.2 fully talented with , a tier 1 Feral Combat talent with 5 ranks), Bear Form and Dire Bear form only.
- : -478 @ max rank (573 fully talented w/ , a tier 2 Affliction talent with 2 ranks), also reduces armor.
- : -410 @ max rank (-574 fully talented with , a tier 2 Fury talent with 5 ranks).
- : Carrion Bird ability, -410 @ max rank.
- Casting time increase
- : Caused by , , glyphed and glyphed . Increases casting, melee and ranged speed by 14% (20% fully talented with , a tier 1 Frost talent with 3 ranks).
- : Tier 7 Arcane talent ability, +30%, also increases ranged attack intervals, each mage can only have one Slow spell active at a time.
- : +30%, each weapon can only have one poison applied to it at a time.
- : +30% @ max rank, each warlock can only have one active curse per target.
- Critical strike chance against target increase
- : Tier 2 Retribution talent, 3 ranks, +1/2/3% against targets debuffed by Judgements.
- : Tier 9 Assassination talent, 3 ranks, +1/2/3% against targets poisoned by the rogue.
- : Tier 9 Elemental talent ability, +3% against foes within 40 yards of the totem, each shaman can only have one active Fire Totem at a time.
- Critical strike chance against target increase (spells only)
- : Tier 6 frost talent, 3 ranks, gives frost talent spells a 100% chance to apply the Winter's Chill debuff @ max rank, increasing spell critical strike chance by 1% per stack, stacks up to 5 times.
- : Tier 4 fire talent, 3 ranks, gives a 100% chance to apply the Improved Scorch debuff @ max rank, increasing spell critical strike chance by 5%.
- : Tier 1 Destruction talent, 5 ranks, causes to increase spell critical strike damage against the target by 5% @ max rank.
- Damage received increase (bleed)
- / : Tier 9 Feral Combat talent abilities, +30%.
- : Rhino ability, +25%, 12 second duration, 1 minute cooldown. Rhinos can only be tamed with Beast Mastery, the tier 11 Beast Mastery talent.
- : Tier 6 Arms talent, +30%, triggered by melee critical strikes.
- Damage received increase (magic)
- : Tier 9 Unholy talent, 3 ranks, requires 3 ranks of . The death knight's diseases cause instead of Crypt Fever, in addition to Crypt Fever's disease damage increase, Ebon Plague increases magic damage by 13% @ max rank.
- : Tier 10 Balance talent, 3 ranks. Causes the druid's and spells to apply the Earth and Moon debuff, which increases magic damage taken by 13% @ max rank.
- : +13% @ max rank, also reduces Arcane, Fire, Frost, Nature and Shadow resistance.
- Damage received increase (physical)
- : Tier 9 Combat talent, 2 ranks, causes the rogue's poison debuffs to increase physical damage caused to the target by 4%.
- : Tier 9 Arms talent, 2 ranks, causes and to increase physical damage caused to the target by 4%.
- : Frost talent, 2 ranks, causes to increase physical damage caused to the target by 4%.
- Healing received decrease
- : Tier 2 Frost talent, 3 ranks, -20% @ max rank.
- : Tier 3 Marksmanship talent ability, -50%.
- : Tier 3 Shadow talent, 5 ranks, -20%, 100% chance of being applied @ max rank by Mind Blast while in Shadowform @ max rank.
- : -50%, each weapon can only have one poison applied to it at a time.
- : Tier 8 Fury talent, 2 ranks, gives whit melee attacks a chance to reduce healing by 25%, stacks 2 times, higher proc rate @ rank 2.
- : Tier 7 Arms talent ability, -50%.
- Hit chance decrease (melee and ranged)
- : Tier 5 Balance talent ability, -3%.
- : -3%, each hunter can only have one sting active on each target.
- Hit chance against target increase (spell)
- : Tier 7 Balance talent, 3 ranks, causes to increase spell hit chance against the target by 3% @ max rank.
- : Tier 8 Shadow talent, 3 ranks, causes , and spells to increase spell hit chance against the target by 3% @ max rank.
Patch 1.11.0: System introduced where weaker debuff could no longer displace a stronger one
Patch 1.7.0: The debuff limit has been increased to 16 (from 8). In addition, the client will now display all 16 debuffs.