[MA] Sweeps and SM question

[callen]

I've been trying to understand how Size Modifier and Sweeps work. I thought I understood the mechanics, but most the GURPS rules seem to work off reality pretty well and if I understand these right they're way off. So I figure I don't understand them. I couldn't find the answer when searching other threads, either.

On your chance to hit, you get the normal bonus for being smaller or penalty for being larger. This sets your effective skill level for the attack. That should be what you use for the contested roll to knock your opponent down. This is where I had thought I understood things.

But now let's have a mouse try to sweep a human. Let's say the mouse is an aggressive little critter (but still a mouse, albeit a clever one to consider a Sweep) and has a little bit of brawl skill, and let's assume a normal person not heavily trained in martial arts or anything like that. There is a huge size differential. The mouse will almost always hit and will be rolling the contested roll against a number in the high teens, near 20. Meanwhile the human rolls the contested roll against a number closer to 10. It seems as though the human who fails to Dodge the mouse's Sweep will almost always fall over. What??? I could stand still (not Dodge) and never fear a mouse knocking me over with a Sweep, no matter how aggressive the mouse. And I'm no combatant. (Well, I trained in biathlon and fencing, but not this type of fighting.)

It seems to me SM should provide a bonus in the reverse direction for the contested roll if the Sweep hits. But I cannot find anything outside of the Grappling rules to hit that suggests that, and I don't see that the Grappling rules to hit apply to the contested roll for Sweep.

Thanks,
Chris

[Aneirin]

They say every time someone asks a question on grappling, DouglasCole appears to whisper sweet nothings about technical grappling and how it will answer all questions (or most) in your ear.

[Gnomasz]

I don't have MA and I'm looking only at the description of Sweep in Characters, but yeah, it's definitely lacking a bit.
But it's not related to SM in my opinion but to ST. If a tiny black hole tried to Sweep a man, he shouldn't have a chance - despite being bigger.
I'd use the "useful grappling" rule of thumb here - you can't sweep someone with more than twice your ST.

[DouglasCole]

Originally Posted by Aneirin

They say every time someone asks a question on grappling, DouglasCole appears to whisper sweet nothings about technical grappling and how it will answer all questions (or most) in your ear.

Hee.

We do have an updated rule for the effect of SM, but ultimately, I'm going to go with a few things here, some of which are Rule Zero applications.

1) What Gnomasz said

2) A Sweep is not a grapple and takedown. It's a way of getting someone knocked to the ground that does no damage, and does not require a grapple. In Basic, it's a weapon skill primarily, though there're unarmed versions in the text and it limits it to using the leg.

One way to perhaps adjudicate this is that you may only use DX instead of ST if your ST is less than 2x that of the guy you're sweeping. So if you're ST 10 vs ST 20, with Sweep-15 due to your DX, you can do Sweep-15 vs. his ST of 20 (or his DX if higher). If you're only ST 9, you're out of luck. Alas.

For the mouse case, that would mean a ST 1 or ST 2 mouse is pretty restricted - our Supermouse can maybe sweep a ST 4 critter, but humans are Right out.

3) With such a big difference in SM, Technical Grappling does have this to say:

Originally Posted by Technical Grappling

Impossible Positions
If you perform any action that changes your or your opponent’s
posture or position such that a grapple is no longer
physically possible – due to reach, facing, relative facing, or
orientation – then you and your foe must release your grip(s);
see p. 00.

While that's not exactly pertinent, it does speak to a Rule Zero application: the GM could just say "no, you can't sweep someone four SM larger than you" and be perfectly justified.

[vierasmarius]

IMO, ideally a Sweep would take into account both DX (whether to-hit vs active defense, or contest of skill) and relative ST / Size. Perhaps it would be something like Push, where success on the skill roll allows a "damage" roll vs the target's ST (in this case still inflicting no wound, and resulting in knockdown instead of knockback). Any time ST-based and non-ST-based rolls are treated as interchangeable you're going to run into serious problems, especially as you move away from SM 0.

[Peter V. Dell'Orto]

Originally Posted by callen

On your chance to hit, you get the normal bonus for being smaller or penalty for being larger.

Yes, it's an attack roll.

Originally Posted by callen

This sets your effective skill level for the attack. That should be what you use for the contested roll to knock your opponent down.

It does? Sweep doesn't say so. It doesn't say you get to roll against the Sweep skill you used to hit. It says to roll a QC of Sweep or ST vs. his ST, DX, Acrobatics, or best grappling skill.

Is there another rule somewhere I'm missing that says your SM difference adds to all contests? And if so, does the larger fighter's SM act as a penalty when attacked by a smaller fighter, so a SM 0 guy vs. a SM+1 guy effectively means a +1 for the smaller fighter?

Originally Posted by callen

But now let's have a mouse try to sweep a human.

Sigh. Because this happens in play a lot.

Originally Posted by callen

he mouse will almost always hit and will be rolling the contested roll against a number in the high teens, near 20.

As far as I can tell, this is not true. He might not miss, but he's rolling base Sweep or base ST vs. the best of the human's ST, DX, Acrobatics, or grappling skill.

Doug's chimed in with an idea about not allowing you to use skill unless your ST is high enough. Probably reasonable - it's hard reasonable that it would be harder to sweep someone much stronger than you, and you might be limited to your ST if you can even do it at all. The Kromm ruling in the FAQ is also good.

Originally Posted by callen

But I cannot find anything outside of the Grappling rules to hit that suggests that, and I don't see that the Grappling rules to hit apply to the contested roll for Sweep.

Like I said, I don't see anything that says you should apply it in the Sweep contest at all. Even if you did, why would it be the bonus you had to hit - your roll to hit and your roll for the QC are not the same, nor are they against the same number.

But again, if someone can show me that SM bonuses to hit are meant to give you a bonus in all grappling rolls/QCs against that target, that would help. I can't find one.

[DouglasCole]

Originally Posted by Peter V. Dell'Orto

Is there another rule somewhere I'm missing that says your SM difference adds to all contests? And if so, does the larger fighter's SM act as a penalty when attacked by a smaller fighter, so a SM 0 guy vs. a SM+1 guy effectively means a +1 for the smaller fighter?

The way we decided on doing it in TG (yes, yes, not out yet, etc) was +1 DX and +15% Trained ST per point of relative SM difference. So technically, you're just a bit more likely to be effective in a skill-based contest, and your size gives you some extra leverage/power, but not that much.

[Peter V. Dell'Orto]

Originally Posted by DouglasCole

The way we decided on doing it in TG (yes, yes, not out yet, etc) was +1 DX and +15% Trained ST per point of relative SM difference. So technically, you're just a bit more likely to be effective in a skill-based contest, and your size gives you some extra leverage/power, but not that much.

But not to the smaller fighter. That's where the mouse is losing out.

The implication in this thread is that:

- you get a "to hit" bonus for relative SM (so a SM-whatever mouse can't miss a SM-0 human)
AND
- therefore you get a relative SM bonus for being smaller, which makes QCs related to grappling easier.

The first is true to a small extent - 3.4.2.23 in the FAQ says you get it but you're limited to +4. Nothing I can find in the rules says it applies to quick contests such as Sweep, which are not a second "to hit" roll.

[DouglasCole]

Originally Posted by Peter V. Dell'Orto

But not to the smaller fighter. That's where the mouse is losing out.

True, true. I was just grabbing the only rule I could think of that applies.

The implication in this thread is that:

- you get a "to hit" bonus for relative SM (so a SM-whatever mouse can't miss a SM-0 human)

If the mouse can get close enough (and this is where the SM whatever mouse needs to get really close to it's target.

AND
- therefore you get a relative SM bonus for being smaller, which makes QCs related to grappling easier.

Yeah, "no way" on this one. I might allow it to apply to things like escape, perhaps, but most grappling stuff, it would be a penalty, not a bonus.

[Tomsdad]

TBH unless your talking about a size difference of only 1 or 2, I'd argue a sweep is impossible in either direction.

There's no way a mouse can sweep a human I think we can all agree on that. But equally there's no way a human could sweep a mouse. Sweep as in the sweep technique, there's all sorts of ways a human could knock a mouse over but none of them are going to benefit from sweep training.

I think the problem here is distinguishing between the physical reality of hitting someone (or grappling them) and sweeping them.

Obviously there has to be some abstract conflation of these in the rules to save our sanity's, but I think there is some room to include the fact that some combat options are really only viable within a certain range of SM variation.