So I was contemplating my latest build, when it hit me - how does the weaponswing mechanic work? If we assume that my primary attack is cleave and that my secondary attack is seismic slam and that I'm using revenge on top of that - how do they work together?
Do I have a fixed amount of attacks in a given period of time? Or do some abilities work independent of the weapon swings? Ie. if I do:
1) a cleave
2) a seismic slam or revenge
3) a cleave
Does that take the same time to execute as 3 cleaves? Or is the "swing timer" associated with abilities seperate from the generator attacks, making the sequence above last 2 cleaves (or somewhere in between 2 and 3 cleaves)?
The system is more complex than that. First you need to understand that there are essentially 5 types of "swing timers".
First are the primary generators, ie Bash, Frenzy and Cleave. Some abilities can be cast on top of these, others can't. The primary generators are cast at a normal rate of speed, ie your listed weapon speed (except for Frenzy obviously).
The second "swing timer" are the buffs. They can be cast on top of the primary generators without a delay in attacks. However, they can not be cast on top of of spenders (BR is counted as a buff even if it costs fury).
Thirdly are the damaging spenders; they are exlusively cast, nothing else will ever be cast at the same time except possibly due to lag. The damaging spenders are NOT cast at listed weapon speed, but slightly faster. The number appears to be around 10% additive IAS faster.
Fourth are the rest of the generators which aren't prim gens, they seem to have a set APS of around 1,2 regardless of the weapon speed equipped. This is probably due to avoid abilities such as Ancient Spear being very slow for 2handers, and very fast for quick 1handers (as it has a notable influence on PvP for example). As far as I know it is not known to the community if this value scales with larger numbers of IAS. They can not be cast with anything else either, they are equally exlusive as the spenders in that regard. These abilities are Ancient Spear and so on, unknown if War Cry follows the buff pattern or this fourth pattern.
And lastly and most weirdly behaving are the situational non-buff abilities such as Overpower and Revenge. If you remember a while back in the beta, it was possible to speed up attacks by interrupting them halfways through, and Blizzard stated that this was a mechanic to make combat feel more fluid and responsive. These abilities seem to detain some of those mechanics, as if timed correctly (used immediately after a prim generator) allows for double casting a primary generator at the same time, or slightly after, and itself.
And thus; in your specific case, the time it would take to complete those three attacks would be (if you have zero IAS)
Thanks for the reply and taking the time to explain - that clears it up :-)
Is there a reason the spenders have the 10% IAS?
It is mostly a psychological thing really. It reinforces that spenders are more powerful than they actually are, even if you don't think about the IAS gain. Imagine if it attacked at something like a -10% IAS penalty, for gameplay purposes people would definitely feel that spenders felt weaker.