The gunner has a very aggressive set of hard coded chains. Some skills have more than one possible chain and will operate with a priority list.

Example:
Skill A is hard coded to chain to skill B, C, and D.
If skill B is not on cooldown, skill A will chain to it.
But if skill B is on cooldown, skill A will chain to skill C.
If skill B and C are on cooldown, skill A will chain to skill D.
If skill A also allows a user defined chain, you need skill B, C, and D to be on cooldown for your chain to pop up.

I really wish we could have got you guys a nice document to explain it all but the time was just not there.

Edited by: SingleBear 2 minutes ago