Heal over time (generally abbreviated as HoT) refers to a type of healing ability. A HoT does not immediately heal a target; a HoT instead heals the target for a certain amount over regular intervals. In World of Warcraft, the healing is typically applied every X seconds (X varies between different HoTs). A HoT may be applied using a variety of methods - from a spell, a bandage (see First Aid), eating food, a potion or some other form. Most HoTs are target specific, though there are also Area of Effect (AoE) HoT's such as the Druid spell Tranquility.
A HoT is in principle a Buff, but usually with a much shorter duration than "normal" buffs. HoTs can usually be removed or dispelled, just like Buffs.
The Druid is the most well-known class for using HoT spells, probably followed by the Priest. Shaman and Paladins have spells which heal over time but the methods are different from the simple buffs of priests and druids. Warlocks and Hunters also have HoTs, although they are not often seen since they are limited to themselves or their pets.
- Priest: Renew, Penance (with talents, channeled), and Blessed Recovery (with talents, self only)
- Druids: Rejuvenation, Regrowth, Tranquility (channeled, AoE), Lifebloom, and Wild Growth
- Shaman: Healing Stream Totem, Earthliving Weapon, and Riptide (with talents)
- Paladin: Sheath of Light (with talents), Glyph of Flash of Light (before Patch 3.0.8)
- Warlock: Drain Life (self only, channeled), Siphon Life (with talents, self only), and Health Funnel (channeled, pet only)
- Hunter: Mend Pet (pet only)
- It is not possible to stack the same HoT from a single healer, but the same HoT from different healers can stack on one target. The exception is Lifebloom, which can be stacked 3 times by the same druid.
- Bandage HoTs are interrupted when the "caster" or the target take any form of damage.
- HoTs cannot crit. If a spell has both a HoT and direct heal component, only the direct heal component can crit.
- Don't waste mana by putting a HoT on someone who is *not* going to take damage
- Each tick of a HoT can cause aggro, but it's spread out over time allowing the tank to build up aggro to counteract it. The difference between HoT and direct heal aggro is consistently gaining small amounts of hate versus gaining no hate for a period of time followed by a sudden large spike in hate.
- Some people like to put a HoT on their tank as soon as they start taking damage, though this may not be advisable if the tank does not generate aggro well. Make sure your tank can at least grab as much aggro per tick as your HoT. This is usually not a worry since a good tank can generate far more aggro per tick than a HoT.
- There is a technique used by some warrior tanks during pulls to use bloodrage to cause some damage to themselves, get into the mob's aggro radius, and then bandage to get some healing threat on the boss while it approaches. Warriors using this technique would prefer not to have initial HoTs on them while they are doing it since they will lower healing amount, and therefor the threat, generated by the bandages.
- Whether a HoT generates aggro depends on whether the healer is in combat with the mob. If the healer isn't in combat with the mob, no threat is generated. In a 5 man instance, it is usually safe to HoT the tank before the pull; the healer won't be put in combat immediately and therefore won't get any aggro. In raid encounters, every raid member enters combat once the boss is pulled. It is therefore only advisable to HoT a tank who is pulling a raid boss if the tank has Hunters helping him out with Misdirection.