[Herr Brackhaus]

I've been musing over this one for a while; do you need the Exotic Weapon Skill to use the grapple gun at all, or is that skill only for using it as a weapon? If the former, when would you ever roll to "attack" if all you want to do is launch the grapple, and what would hits give you?

[Medicineman]

By RAW you can not default an Ex.Weapon Skill, so you can not pick it up to shoot the Grappel ( just like with Laserpistols)
But my Common Sense cries Havoc when he noticed that .(even now, while I'm writing this my head hurts from the Facepalm )
So , My Houserule would be to simply default to AGI (or use Projectile Weapons because thats what a Grappling hook is ) and be done with it

Additional Hits...
A GM could raise the treshold for a succesful throw/shot/whatever and additional Hits could be used to beat them

with an exotic Dance
Medicineman

[Herr Brackhaus]

Yeah, the no defaulting thing actually changed from SR4 to SR5; it was one of our first houserules, as firing something like a laser pistol or a flame thrower or indeed a grapple gun shouldn't be 100% impossible without training, just difficult.

I guess a follow-up question is: how do y'all run the grapple gun at your tables, specifically, do you need to roll "to hit" to get a secure grapple?

[MijRai]

Well, if I were to run a Shadowrun game anytime soon, I'd just chuck the grapple gun (and harpoon gun, for that matter) into the Archery skill.  And I'd require the same as landing a grenade where you want it to get a secure grapple; 3.  Unless there's other circumstances.

[Medicineman]

ahhh
Your Archery is Projektilwaffen in German = projectile Weapons
( and using Grenade Rules is a good Idea , I'll take that for a Doller )

with a German Dance
Medicineman

[Sterling]

Our group took a simple approach; if you are simply using it to attempt to place the grapnel then no roll required.  If you're attempting to go Rorschach with it and use it as a weapon the Exotic Weapon Proficiency is required.

Its not the same as pointing a pistol and firing.  The thing is front heavy until you fire, so there is a special technique completely unlike firing a handgun.  At least that was the rationale we adopted.

[Rooks]

As long as you are shooting at a relatively large target (ie a building or rooftop) no roll should be required its not like you can over shoot a rooftop or miss a broadside of a building unless under extreme circumstances, on the other hand, shooting a moving vehicle to latch onto it shoot require a roll

[Mittensworth]

I've always liked the optional rule in the core rulebook that stats you can substitute a similar active skill for another active skill at a dice penalty at the GM's discretion.  When I GM I allow my players to use the pistols skill at -2 dice, which makes sense for me.  Its weighted differently, and 2 dice is a significant enough penalty,

[Blue Rose]

Personally, I'd roll the use of the grapple gun into your Climbing check.

[Shadowjack]

One thing to consider is that missing with a grapple gun can be heard, especially after multiple failed attempts. It is also a very awkward thing to fire compared to a gun, at least I would assume. If you want to be really accurate with a grapple gun you should grab the skill. If you don't mind missing a few attempts, defaulting should be allowed imo.