What exactly does it mean to "break" a subroutine? Does it no longer exist for that encounter? I think the answer hinges on a few things.
1. When subroutines trigger. My assumption is that subroutines have already been triggered by the time the runner gets to break them.
2. Is breaking preventing? Preventing specifically stops an effect from resolving rather than from triggering.
I think of subroutines as triggering on encounter or some other timing near there and breaking as preventing those subroutines from resolving. But I'm not entirely sure that it's that cut and dry. I could also see subroutines as having some kind of trigger like "when the runner ends interaction with this ice, do X unless the runner broke this subroutine", in which case breaking is something completely different from preventing.
The reason I'm asking is for this question: can I use more than one Grappling Hook to break all the subroutines on a piece of ice?
If subroutines always exist and breaking is its own thing entirely, it would follow then that I can break all but one subroutine with one Grappling Hook and then use another Grappling Hook to break all but a different one subroutine. But if breaking is more like preventing or subroutines cease to exist in some capacity after being broken, then obviously this maneuver would not work.
Submitted by Jacob Morris on September 26, 2014