CR: 3.4.7.b - ICE subs can be broken #2016
Description
Ice are the only cards with subroutines. A piece of ice may have any number of subroutines in its text box, each one indicated by the [sub] symbol.
Before the subroutines on a piece of ice resolve during an encounter, the Runner has the opportunity to break them. A broken subroutine does not resolve. See rule 6.5.4.