About Attack Duration buffs

[Gabli]

I’ve recently taken the time to make a bunch of measurements concerning the effect of “- x% Attack Duration” bonuses. The basics, which are not that basic, are from this thread from moebius92.

As a reminder, here is the way things seem to work when you fire a “standard” skill (neither marked Fast nor Immediate in the tooltip):

• If the skill has an induction, it happens first.
• After the induction time is ended, the skill starts activating. This lasts for a duration noted “ACT” and is visually spotted by the skill’s icon borders being green.
• After the skill has finished activating, its cooldown phase starts. For some skills, any other standard skill that is queued will not start until a post-skill delay (“PSD”). The sum of ACT and PSD, called “global cooldown” and noted GCD, is noteworthy as Attack Duration buffs are directly affecting this time laps.

Variations occur when using a “Fast” or “Immediate” skill while a previous skill is activating:

• Fast skills allow to negate the previous skill’s PSD: the latter starts activating immediately after the previous one finished activating.
• Immediate skills start activating the moment they are clicked/keyed. Such a skill negates not only the previous skill’s PSD, but potentially its ACT too (bar anti-macro bugging). As such they also allow to start the previous skill’s cooldown sooner. According to moebius92 a third skill can’t start activating until the last of both skills’ GCD have ended: this is not something I tried to confirm but there is no reason to assume it works any other way now.

You’ll find in the following posts in this thread:

• The main results of my tests.
• The general idea of how ACT, PSD and GCD are measured.
• An explanation of how measurements’ accuracy is estimated.
• Some details on tests conducted on my (dwarf) Champion.
• Some details on tests conducted on my (female elf) Hunter.
• Details on the determination of the cap value of Attack Duration bonuses.