Technical Grappling: Foot Pin
 

In the school where I train (Modern Arnis), one of the things we do with our footwork is something we call a "foot pin".

You use the ball of your foot and your body weight to pin the lead foot of your opponent in place. It makes it very difficult for him to do any sort of foot work, and makes unbalancing him much easier. It also makes a retreat VERY difficult.

How would you represent this in GURPS? It's not a Stamp Kick because we aren't bringing our foot down hard enough to do damage. Is it a grapple? What kind of effects would it have? A penalty to dodge/retreat?

Here is an example of a foot pin (though these guys call it a foot trap) in action.

Thoughts?

Re: Technical Grappling: Foot Pin
 

I'd treat this as a one-legged grapple of the other guy's foot. You'll get a bonus for using your own legs, and as a GM, you might look to a very specific application of the Grappling Encumbrance Multiple (p. 8) to make this hard to escape.

As an attack, you step on the other guy's foot. This is an attack using your foot (-2 to DX or your best unarmed grappling skill) on the other guy's foot (another -2).

If you hit, you roll CP based on a one-footed grapple. They won't be much, though. Based on 0.6xST, but hopefully you're using Wresting at DX+2 for the best Trained ST you can get.

If you inflict more than -2 penalty to DX (and since you're rolling vs 1d-2 or so CP, that's not likely) you might make him technically unstable.

To get out, you can impart a penalty based on trying to move half of your weight with one foot. Give his foot 0.6xST.

So two ST 12, 180-lb fighters. One-footed ST is about 7. BL for that is about 10 lbs. So you're dealing with 9xBL, which is a -6 when trying mass-based moves, and yanking your foot away (attacking to break free) would qualify in this case.

Re: Technical Grappling: Foot Pin
 

That looks right, but is woefully ineffective mechanically.

I certainly wouldn't qualify for the "Wrestling" skill. Maybe Judo. But regardless, the foot pin, as we do it, is much more effective than that.

It becomes much easier to knock someone down or push them over when their foot is pinned.

It's a complete disruption of their footwork. And while it's certainly not impossible to pull your foot away from a foot pin, trying and failing will very likely disrupt your balance.

I'm wondering if an effective representation of how this works might just be below the resolution level of GURPS.

Re: Technical Grappling: Foot Pin
 

Buy it off of whatever your primary weapon skill is, using a Technique Adaptation perk. That way it becomes an attack based off of something you've trained in.

Check out Stability, which is on p. 9 or p. 10. The foot pin could make you unstable if done right, which doubles the effects of CP spent, and while we didn't cover slams and shoves, I'm sure that the "double the impact of the effect" would work out well.

Re: Technical Grappling: Foot Pin
 

I've done a lot of thinking about just that, since that's something that in real life often follows a grab of a leg or other disruption of someone's stable stance.

I'm considering treating Shoves something like a Destabilising Strike, actually. Most Shoves aren't enough to knock people down, but they do tend to cause a momentary imbalance and make it easier to follow them up with a proper strike or grapple, as well as disrupting an attack from the shoved party.

Re: Technical Grappling: Foot Pin
 

Another way to go would be to borrow the Sweep model. It's a non-damaging takedown that will benefit from CP. Treat a strike or shove as the initial CP roll, apply that as a penalty to any rolls to stay upright if you're unstable, or something. Making stuff up off the cuff here, but between Destabilizing Strike and a modification of Sweep, there might be something there.

Re: Technical Grappling: Foot Pin
 

I've been considering what animals do in combat, i.e. shoving with the shoulder before going in for a bite or stamp.

Looks a lot like a move that's meant to cause very short-lived CPs that give the other party a penalty to strike back or defend, in order to get in a fight-ending move.

Horses rarely knock each other over, but back when stallions fought each other as a sport here in Iceland*, most descriptions seem to involve a shoulder shove before the fight ending move.

This also happens when two riders fight. Their horses can shove one another, to interfere with the strikes and defences of the other rider.

*Long time ago, don't worry.