i don't have my books, so it's possible that this question is already answered and i just don't remember. as i recall, the limit on centering is that it can only be used on one action during any init pass--if you use two simples to fire your pistol twice, you get to center on one of those shots; if you use a complex to fire off an autofire burst, you get to center on it.

this doesn't cover several combat options, however--namely, instances where a single action (simple or complex) results in multiple rolls. i can think of three examples off the top of my head: when you use an action to fire a weapon from each hand; when you use suppressive fire on multiple targets; when you use a single complex action to attack multiple opponents in melee. how does centering apply in situations like this? are you allowed to center only on one of the rolls? do you center for each roll individually? center once, and apply the results to all rolls, or maybe split the results between the rolls as desired?

Not sure what you're talking about there at the beginning 'cause that's basically how it's always worked as far as I know.

Adepts have to spend a Free Action to use Centering, and once used they only gain a single benefit from Centering (extra successes, reduced penalties, etc.) for that phase. There's no limitation on the number of actions you have in that phase or anything of the like. The only limitation is that you only get to make one Centering Test. If you're an adept using Centering for extra successes while shooting with a pistol, you just have to split those extra successes between both shots; you don't get to make a seperate Centering Test for each one.

The rules don't really cover that sort of thing, so I say you're forced to make it up.

There are instances where centering successes count twice, so there is precedent for that sort of doubling if you want to do that.