[top]Global Cooldown
The global cooldown is the time that must elapse between actions taken by the player. It was implemented to limit macroing and botting, but it also prevents low ping players from gaining an unfair advantage over high ping players by limiting the number of actions per minute that can be executed.
The base global cooldown for Druids in cat form and Rogues is 1.0 seconds. The base global cooldown for all other classes is 1.5 seconds.
[top]Lowering the Global Cooldown
As of 2.4, spell haste will lower the global cooldown
when casting spells to a minimum of 1.0. The reduction amount is equal to the percentage of cast time reduced by spell haste, up to a maximum of 33% (requires 50% spell haste). The reduction scales smoothly, meaning your GCD can be any value between 1.0 and 1.5 depending on the amount of spell haste. 50% spell haste requires 788 spell haste rating at level 70; the value required at level 80 is higher (if you know it post it in the comments).
[top]Non-GCD Abilities
Not all abilities are tied to the global cooldown, however all these abilities have some sort of separate timer that prevents them from being spammed indefinitely. Some
examples of abilities that do not incur the GCD when activated include:
- Most clickable trinkets
- Most pet abilities
- On-next-swing abilities like Maul or Cleave
- Warrior Stance Change, Shield Block, Taunt, Bloodrage, Spell Reflect
- Paladin: Divine Favor
- Hunter: Kill Command
- Mage: Presence of Mind, Arcane Power
- Warlock: Fel Domination, Demonic Sacrifice
- Shaman, Druid: Nature's Swiftness
[top]Macroing Non-GCD Abilities
Non-GCD abilities may be macroed together in sequence and in combination with a GCD-invoking action. Some examples:
Nature's Swiftness + Heal
/cast Nature's Swiftness
/cast Healing Wave
Trinket + PoM + AP + Pyro
/use 13
/cast Presence of Mind
/cast Arcane Power
/cast Pyroblast
[top]Changing Gear
Changing equipment (weapons, shields, etc) in combat triggers a GCD, and will interrupt any spell being cast when you attempt to switch. This was added to prevent mid-cast weapon switching, since the spell cast's calculations used the spellpower stat present at the end of casting rather than the start.
[top]Bloodlust/Heroism
Bloodlust and Heroism will not lower the global cooldown for abilities that do not benefit from spell haste. Abilities that make use of spell haste receive the benefit of Bloodlust lowering their global cooldown as noted above. This can be proven using the following UI hook and spamming an instant spell with no cooldown inside and outside of Bloodlust/Heroism:
/run hooksecurefunc("CooldownFrame_SetTimer", function(_, start, duration, enable) if start > 0 and enable > 0 then DEFAULT_CHAT_FRAME:AddMessage(duration) end end)