Damage over Time, generally abbreviated as DoT and or simply dot, refers to inflicting some damage on one's foe which will be applied at a regular interval for a limited duration. Typically in World of Warcraft, the damage is applied every X seconds, where X varies from one tick (when periodic damage is dealt once, one interval) to the next. A DoT may be applied using a variety of methods — from a spell, a trap, a weapon, a poison, or some other form. Most DoTs are target specific, but some are also used as Area of Effect (AoE) attacks.
While all damage dealing classes have some form of DoT, the Affliction Warlock and Shadow Priest are most reliant on DoTs as the backbone of their DPS rotation.
Damage over Time effects are most effective when they are allowed to run their full course. Also, DPS based on multiple DoTs has a significant ramp-up time as it takes several Global Cooldowns to apply them all to a target. As such, DoTs provide sustained DPS, without the "burst damage" of an equivalent Direct Damage attack.
DoTs in PvE are most effective in extended fights against one or more long-lived targets, and least effective in short trash pulls where the targets are downed quickly, or fights that require frequent switching to new targets. DoT-reliant Warlocks and Priests can find it hard to maintain competitive DPS against trash without high-end gear, and will often fall back solely on Area of Effect spells in those situations.
In PvP, DoTs are vulnerable to being dispelled, but have the advantage of continuing to cause damage if the caster is silenced, out of range or even dead. This leads to tactics such as the Warlock's infamous "dot, dot, dot, fear". The target has no chance to dispel the DoTs until they have broken the fear, while the caster is free to heal, run away or cast further offensive spells while their opponent takes damage from the DoTs. To compensate for their vulnerability to being removed before they have fully affected a target, some DoTs such as the priest's Vampiric Touch will also cause additional damage if dispelled.
- Death Knights with Icy Touch, Plague Strike, and Unholy Blight.
- Druids with Moonfire and Insect Swarm (in generic caster or Moonkin form), Rip, Rake and Pounce (in Cat Form), and Lacerate (in Bear Form).
- Hunters with Serpent Sting, Immolation Trap and Explosive Trap as Area of Effect DoT.
- Mages with Living Bomb, and Fireball, Frostfire Bolt, or Pyroblast (although these are primarily DD spells, they also add a small DoT even when offspec), If specced, fire spells criticals will put on the enemy a dot through Ignite talent which deals 8-40% of the damage done for 4 seconds.
- Paladins using Seal of Vengeance and Consecrate in a way. If specced, Divine Storm and Judgement spells criticals will put on the enemy a dot through Righteous Vengeance talent which deals 40% of the damage done for 8 seconds.
- Priests with Shadow Word: Pain, Vampiric Touch, and Devouring Plague.
- Rogues with Deadly Poison, Garrote, or Rupture.
- Shamans with Flame Shock (a DD spell with DoT). Magma, and Searing Totems may also be considered DoT (or AoE).
- Warlocks with Immolate, Corruption, Curse of Agony, Curse of Doom, Seed of Corruption, or Unstable Affliction.
- Warriors with Rend, also if specced, their melee criticals will apply a Deep Wound that deals 60% of weapon damage.
- Most spell-based or poison-based DoTs can be cured by potions or spells.
- Most methods of Crowd Control are broken if the target has a DoT on them.
- Most DoTs cannot crit, but some classes can with the proper talents or set bonus. (See Glyph of Explosive Trap)
- Rogues and Cat Form druids who stealth while a DoT is still on them will come out of stealth when the next tick of damage is inflicted.
- First Aid will be interrupted by a DoT.
- When reapplying a DoT to a target, casters must time the spell carefully. Cast too late and you miss out on a potential tick of damage, cast too early and you will "overwrite" the last tick of the previous cast.
- This term is often referred to as periodic damage by Blizzard.
- Prior to patch 3.3, classes that relied heavily on Damage over Time (and Heal over Time) effects complained of scaling issues, as their effectiveness did not increase with gear upgrades at the same rate as direct damage classes. This was remedied in the 3.3.0 patch by the introduction of glyphs for Warlocks and Restoration Druids, and a change to Shadowform for priests, all of which allowed the caster's Haste to effect their core periodic spells.