Knockback - why ST not HP?

[GWJ]

If slam damage is determined with HP (which are "mass" in greater mean than ST), then why knockback is determined with ST?

[Gollum]

I don't know if it is the right answer but, in my humble opinion, ST is the ability to use muscle power, so to push things and resist to things trying to push you. Hence knockback being based on ST rather than HP - when both are different.

[GWJ]

Hm you're right, it's resisting that counts. But still, in case of knockback caused by bludgeoning damage, I think nobody resists intentionally (this means charging into attack vactor)

[smurf]

iirc the damage has to equal ST-2, which means on average doing 8 damage before modifiers to move the defender back 1 yard.

Remember if armour blocks the actual damage it does not prevent the knockback.

There are abilities to create double knockback damage.

This may cause the defender to stumble. After the first Yard it is a DX test with penalties = to yards knocked back.

[Gollum]

Originally Posted by GWJ

Hm you're right, it's resisting that counts. But still, in case of knockback caused by bludgeoning damage, I think nobody resists intentionally (this means charging into attack vactor)

You're right. Resisting knockback is not always (surely never, actually) intentional. It is pure reflexes.

Now, basing knockback on HP rater than ST would mean that your ability to resist knockback would become lower and lower when you are injured. It could make sense ... But what would happen if your HP reach 0 or even a negative score?

Of course, authors could have ruled that it is based on starting HP, but since HP are based on ST and rarely differ a lot, it may just be much simpler to based knockback on ST ...

Just imagine an old and sick elephant with very few HP left. Is his resistance to a mace blow knockback much lower than when he was younger and in full shape? Not really.

[GWJ]

Originally Posted by Gollum

You're right. Resisting knockback is not always (surely never, actually) intentional. It is pure reflexes.

Now, basing knockback on HP rater than ST would mean that your ability to resist knockback would become lower and lower when you are injured. It could make sense ... But what would happen if your HP reach 0 or even a negative score?

Of course, authors could have ruled that it is based on starting HP, but since HP are based on ST and rarely differ a lot, it may just be much simpler to based knockback on ST ...

Just imagine an old and sick elephant with very few HP left. Is his resistance to a mace blow knockback much lower than when he was younger and in full shape? Not really.

It's not what I mean :) I mean rather "full HP" value instead of "actual" - much like this -1xHP; -2xHP; -3xHP tresholds for death checks.

But maybe this is the case. To account effects that are lowering/raising ST score, like much fatigue or something.

[Boge]

Being overweight gives you a bonus to not being knocked down. It has nothing to do with strength.

[GWJ]

I wouldn't say that. "Nothing to do" is almost certainly wrong statement. I think "strength is not everything" would be much closer to truth ;)
But you gave me helpful idea - good reason to giving mass-realated traits to characters with more or less HP than ST :)

But still I'm very curious why rules are for pure Strength with no actual HP (mass) accounting, not speaking about encumbrance (I think it's much harder to shove guys with very heavy armors)

[mr beer]

Really it should probably be based on mass rather than either ST or HP. But I can see how that would get fiddly.

[Gollum]

In GURPS, mass is represented by ST, not by HP: "ST measures physical power and bulk". ST determines your height range, which determines your weight range, and so on.

Of course, you can disconnect mass from ST, with advantages and disadvantages (overweight, skinny, gigantism, dwarfism ...). But they are still basically connected, exactly as Per or Will are basically connected with IQ.

HP are the ability to sustain injury. It depends on mass, which is why it is basically connected with ST, but it is not only mass. It is also toughness, pulsion of life, etc.

You can have an elephant with fewer HP than other elephants, or a rat with more HP than other rats. It wont make them more or less resistant to knockback.

Edit: I don't think that resistance to knockback is reduced by fatigue, but I'm not sure.