Why does this macro work?

[Ashley]

I've seen this macro scattered in different places on this forum, and assumed it wouldn't work because of what I know about WoW macro mechanics. I decided to try it just in case, and discovered that it works! Now I want to find out why!

/castsequence reset=combat Flame Shock, Lightning Bolt, Lightning Bolt, Lightning Bolt, Lightning Bolt, etc
/cast Lava Burst

I assumed that since every item in the castsequence triggers the GCD, it would prevent the Lava Burst from casting. Instead, it casts the flame shock first, then the lava burst, then lightning bolts while lava burst is on cooldown, and lava burst whenever it's ready.

What. The. F.

I did notice that if I don't spam the key, (press it once, flame shock, wait for gcd to be gone, press again) it casts the lightning bolt next instead of the Lava Burst. Therefore, you have to spam this key to get Lava Bursts to go through. Does this mean that GCD forces the macro to fall through the cast sequence and land on the Lava Burst? Is this behavior maybe due to the spell queue system for lag?

So, would this be sufficient key replacement for all 10 of my toons to spam?

And maybe made even faster through ISBoxer to pass the key on press OR release?

[Tehtsuo]

So, would this be sufficient key replacement for all 10 of my toons to spam?

And maybe made even faster through ISBoxer to pass the key on press OR release?

That's what I did for my 5 shamans. It seems to work pretty well, although I'm betting once I start getting closer to 85 and/or geared the 2 step system may need to come into play to provide max dps. One thing I like about it is if you have glyph of unleashed lightning, it's completely compatible with movement without making any changes, as long as you only have shocks and lightning bolts in the castsequence.

[MiRai]

And maybe made even faster through ISBoxer to pass the key on press OR release?

You can't cast faster than the global cooldown allows so... it doesn't matter.