Knockback, Weight, Armour and low ST

[dfinlay]

The knockback rules on B378 seem to have some issues with them. It appears to use ST-2 as a mass analogue (which is odd, as GURPS generally seems to use HP for this), but there doesn't seem to be a factor for weight carried. It should be harder to shove back someone who's in heavy plate than who's not, but there doesn't seem to be such a mechanic in the rules.

Additionally, what happens to ST 2 or lower creatures. If you try to shove a small cat (Is that ST2? It seems reasonable to me), you'll knock it infinite yards back by the rules. Not to mention something like a telepathic statue which might weigh a tonne but have ST 0.

Basically, the Knockback on B378 rules don't seem to work very well at all. Is there some other version of these rules somewhere or am I just missing something and they work fine?

[RobKamm]

Originally Posted by Basic Rulebook

If the target has ST 3 or less, knockback is one yard per point of basic damage!

That's from about half way down in the box.

As for the concern about equipment I think that may be misplaced. I've fought in armour, and reeved many people wearing it, if anything armour pulls the wearer's center of gravity up and it becomes easier to fall/be knocked down. I'm not sure if it rises to the level of being worth hassling with, but if I wanted to I'd go with subtracting Encumbrance/2 (round down) from the threshold.

I can see your argument for using HP rather than ST.

[T.K.]

Hmmm...guys...did you even read the rules for knockback on Basic p. 378?!

As RobKamm stated on the second reply to this thread the rules not only explicitly state what happens for ST 3 or less targets but ALSO spill quite clear what happens when a target has no ST score: "(...)If the target has no ST score at all (like a wall), or is not resisting, use its HP instead.(...)"

From there, you can quite easily extrapolate what happens to edge cases...

The rule is completely practical, imo

[Edges]

As a simple house rule to account for encumbrance in Knockback, you could add the encumbrance penalty to ST (or HP if you are using that instead). So, for example, someone with an 11 ST that is heavily encumbered would be treated as having a 14 ST for Knockback purposes.

'Just a thought.

[roguebfl]

ST is used for animate objects cabile f tryin to resist knock back and HP for inanimate object who mass is the Only issue.

[GodlessRose]

Originally Posted by T.K.

Hmmm...guys...did you even read the rules for knockback on Basic p. 378?!

Reading the relevant rules before commenting is a serious violation of the guidelines for this forum.

[Anthony]

The knockback rules don't have a lot of connection to reality, but it's not really possible to generate accurate knockback values if your only data points are damage and target ST/HP. On the other hand, you can generally come close enough by simply removing knockback from your games -- realistically only collisions can cause knockback, and the amount they would cause is almost totally unrelated to the damage they do and should probably be baked into the slam maneuver (a 10 HP man hitting a 10 HP man at move 10 will cause 1d damage, but after the collision both will be moving at an average of move 5, and will travel 2-3 yards before hitting the ground. A 1 hp mouse hitting a 10 hp man at move 100 will also cause 1d damage and will not cause him to move at all, except possibly as a response to pain or mess).

[dfinlay]

Originally Posted by Polydamas

GURPS can't built core rules on the assumption that a game has neither robots nor golems. That just does not fly. So the rules for knockback, collisions, etc. had to allow for normal, Unliving, and Homogeneous entities whose HP for a given mass can differ by a factor of four.

True. That said, this seems like an even larger issue for ST-based knockback. You can easily have 1 tonne robots with 2 ST (they exist in real life) or tiny pixies who magically have 20 ST. Knockback rules wind up absurd for these. When I mentioned URPS using HP as a mass analogue, I was referring largely to the collision and slam rules where they quite clearly do seem to be doing that. Hmm...

Originally Posted by T.K.

Hmmm...guys...did you even read the rules for knockback on Basic p. 378?!

As RobKamm stated on the second reply to this thread the rules not only explicitly state what happens for ST 3 or less targets but ALSO spill quite clear what happens when a target has no ST score: "(...)If the target has no ST score at all (like a wall), or is not resisting, use its HP instead.(...)"

From there, you can quite easily extrapolate what happens to edge cases...

The rule is completely practical, imo

I'm sorry. I was really tired when I posted the OP and did miss these things. As for the "if not resisting, use HP" thing, that's really weird, since HP is often higher than ST. Can I choose not to resist knockback in order to boost my knockback resistance? Additionally, the 0 ST causes a similar problem where the 1 ST, 10 HP creature resists knockback 8 times worse than if he were unable to exert force and had his ST dropped to 0.

Originally Posted by Anthony

realistically only collisions can cause knockback

Not really true. Perhaps most personal weaponry doesn't, but many attacks designed to do knockback, often with no wounding, such as shoves, pressurized water jets, etc. should definitely do knockback and at least without rewriting how those work, need to piggyback on the knockback rules. A few other attacks should as well such as, for example, a cannonball hitting your chest (with a force field letting you survive it), but I'm primarily concerned with things like Shoves.

[whswhs]

Originally Posted by dfinlay

Additionally, what happens to ST 2 or lower creatures. If you try to shove a small cat (Is that ST2? It seems reasonable to me), you'll knock it infinite yards back by the rules. Not to mention something like a telepathic statue which might weigh a tonne but have ST 0.

An animal's body weight is approximately equal to half its racial average ST, cubed. ST 2, divided by 2, is 1, and 1 cubed is 1. No domestic cat is that tiny.

ST 4, divided by 2, is 2, and cubing it gives 8, which is what our smaller cat weighs. ST 6, divided by 2, is 3, and cubing it gives 27, which is a few pounds more than our bigger cat weighs.

That's not to say there isn't a problem with small creatures. A rat might have ST 2, for example. I think you have to view the knockback rule as a gameable abstraction suitable for man-to-man combat.

[Flyndaran]

Gurps tries to be generic, but still has many human centric rules that make no sense for tiny or giant characters.

27 pounds? Is that a pure house cat or part cougar?
Though felines tend toward greater burst strength than other comparably sized mammals.