Multi arm ripping ST

[Jose]

So I'm building a SM +4, ST 150 mecha and its great. It has 4 powerful strikes that it can lash out with and boy do they hit hard!

One thing I was thinking about was the possibility of lifting heavier things in its arm and ripping them apart. Looking through GURPS Basic and Martial art I could not find anything on how to actually do it. The big query is how much does having two extra arms help in this? The more ST for ripping apart the better, and extra arms ought to help.

[Tomsdad]

Originally Posted by Jose

So I'm building a SM +4, ST 150 mecha and its great. It has 4 powerful strikes that it can lash out with and boy do they hit hard!

One thing I was thinking about was the possibility of lifting heavier things in its arm and ripping them apart. Looking through GURPS Basic and Martial art I could not find anything on how to actually do it. The big query is how much does having two extra arms help in this? The more ST for ripping apart the better, and extra arms ought to help.

If your doing this to an opponent I'd do this via the "wrench limb" rules in Technical Grappling (aka TG). Although if you've got a big enough advantage in SM I'd probably just call it "wrench opponent", and not bother with targeting an actual limb. Although at some SM difference you still can if you want.


There are rules for combining extra limbs there as well.

So using those rules. With a basic ST150 for each pair of arms, each pair will have a BL of 4,500lb. Two sets of arms will have a combined BL of 9,000lbs which is a combined ST 212 for grappling.

You are going to be inflicting a lot of Control Points* with that ST, you'l also be inflicting a lot of damage as a lot of these grappling move's damage output is based on the lower of the margin of QC success or CP set for the task, and you are potentially going to be doing well in both if you are doing this to something smaller and weaker!

Say your SM4 ST150 DX10 HT10 (ST212 with all four arms grappling) robot is doing this to SM2 ST50 DX10 HT10 target**


Thanks to that +2 net difference in SM your robot is going to have +2 to DX when grappling and +30% on ST for grappling related stuff, so that ST212 will become ST276 which means Thr damage is 28d!

So we'll assume the robots grappled his opponent with all four arms so is going to be inflicting 28d control points, so an average of 98. With ST50 and DX10 and 98 CP conferring stat penalties even without having to spend any, your robot's opponent isn't going to be escaping that or even removing any CP from the grapple in their turn! In fact your ST50 DX10 target has just dropped to ST1 DX1!

So the next round's Wrench QC will be a ST272 vs. HT10***

Which assuming both roll a 10, is a net MoS of 262 for your robot, so the amount of Cr damage you inflict is really down to how many of those 98 CP you want to spend and convert into damage. Which will depend on if you want to keep the grapple going and do it again next round, or get it all done in one messy go!


Ultimately I went with "Wrench limb" here as it's the absolute closest I could think of to grabbing and pulling apart. But the reality is at these ST and SM differences there are several moves that could be used to demonstrate your robot doing terrible, terrible things. (grab and smash, wench spine, bear hug etc). Obviously if you're closer to parity in ST and SM it becomes less one sided, as the lower threshold of MoS or CP spent kicks in differently!

If your doing this to an inanimate object I'd use the combined limb ST rules above and just inflict Thr cr damage. Which is in fact what your functionally doing in the example above anyway, if you spend all your CP!

NB: While I use TG in my games I don't do a lot of really high ST or SM difference in my games, so I may have got some of the above wrong, apologies if that is the case!





*if your not familiar with TG Control points are the currency you accumulate and expend when grappling and then doing things to your grappled target

**for the sake of simplicity I'm going to say neither has enough skill to get a trained ST bonus (I'm also using normal ST/BL not "Know your own Strength" from Pyramid)

**best eligible stat for the QC your target's got thanks to the ST & DX reduction due to being subject to a 98CP grapple!

[Tomsdad]

Sorry I realise the above is a bit full on! And if you going to be doing this as part of picking up heavier targets you can get into relative mass based moves.

If your not using Technical Grappling, and just want a way of working out how much extra damage using an extra 2 arms does in abstract when applying all four together like this. Just use the combined limbs rules,

Which is basically assuming each pair of arms have the basic BL, add both BLs together and work the ST to BL calculation in reverse to give you your new ST to then get damage ratings from.

So in the example above is:

ST150 = BL 4,500 (150x150)/5 = 4,500

So for this calculation a pair of ST150 arms has a BL of 4,500 therefore two pairs has a combined BL of 9,000 so the derived ST is:

Square root of (9,000*5) = 212 which is Thr 22d

and just apply that damage as you see fit in your game.


I would recommend TG though, it works smoothly and gives good results even for extreme stuff like this

[Jose]

Thanks @Tomsdad

Thats immensely helpful. I got what I needed, thanks for the help. I was just not sure how to deal with this.

[Tomsdad]

Originally Posted by Jose

Thanks @Tomsdad

Thats immensely helpful. I got what I needed, thanks for the help. I was just not sure how to deal with this.

No worries, have fun tearing things apart!

Cheers

TD

[Harald387]

If you don't have or don't want to use Technical Grappling, see the Wrench Spine & Backbreaker techniques from Martial Arts.

[Tomsdad]

Originally Posted by Harald387

If you don't have or don't want to use Technical Grappling, see the Wrench Spine & Backbreaker techniques from Martial Arts.

Yep you are right, sorry I didn't mean to give the impression that you could only "wrench limbs, back break etc" in TG. The rules in TG just supplement the ones in Campaigns and Martial arts!