Multi-subroutine taxing Ice getting you down? Make the Corp sad that they bothered to rez it.
• Cheap to install at only 2 [credits].
• Only 2 Influence, so quite splashable.
• Not an icebreaker, so does not require strength match to interact with the Ice.
• Some multi-sub Ice has routines that you don't care about:
-- e.g. Inazuma if you plan to continue running anyway.
• Not an icebreaker, so cannot be searched for with Special Order.
• The most glaring weakness is single subroutine ice, such as the rather popular Wraparound.
• Trashes itself to break the subroutines, so you need recursion to do it again.
• Some multi-subroutine Ice, esp. Barriers, you definitely do want to break all the subroutines rather than waste the Grappling Hook.
• Obviously e3 Feedback Implants can be used to break the last unbroken subroutine.
• A program that trashes itself can be a trigger for Exile's ability.
• Note that it does not combo with itself/another copy:
-- when the first Grappling Hook fires and breaks all but one subroutine, there is only one unbroken subroutine left for a second Grappling Hook to fire at, so the second misses.
• If Quetzal doesn't have an e3 Feedback Implants down yet, this can fire first to break all but one Barrier subroutine, then her ability kicks in.
-- for the same reason paired 'Hooks don't work, timing Quetzal's ability with this is important against Barriers with 2 subroutines; if Quetzal fires first against, e.g. Eli 1.0, then the remaining unbroken subroutine is not a valid target for Grappling Hook.