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.

[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.

[whswhs]

Originally Posted by Flyndaran

27 pounds? Is that a pure house cat or part cougar?

As I said, a few pounds less. The last time he was weighed he was 18 pounds, but he's gained since then, we think.

[Flyndaran]

Originally Posted by whswhs

As I said, a few pounds less. The last time he was weighed he was 18 pounds, but he's gained since then, we think.

Oh well, my tubby Timmay is around 18 pounds. But 27 is half again as heavy and more the size of a bobcat than house cat.
Serval hybrids can get that large, so my joke was not entirely silly.

[Bruno]

One of our cats was 24 pounds when we adopted him, but he was Very Fat in GURPS terms (or worse). My neighbors had a 28 pound cat, on the other hand, that was a healthy, intact male, active outdoor cat, a Maine Coone which is a breed notorious for being very big, particularly the males. And yes, that's rapidly approaching the size of a bobcat, he was a serious cat.

On topic, we use HP instead of ST, no particular damage done to our games, and we cap it at 1 yard, because otherwise a HP 1 creature suffers negative knockback, which offends me just as much as the DIV BY ZERO error a HP 2 creature gets :D

This does mean you can probably drop-kick a small turtle one to four yards, depending on your damage roll, poor turtle. That's pretty reasonable, if cruel.

Those low HP creatures are usually going to be crippled or killed by any attack significant enough to cause knockback, so the details of where they stop moving usually stop mattering very quickly.

[Nereidalbel]

Originally Posted by Bruno

On topic, we use HP instead of ST, no particular damage done to our games, and we cap it at 1 yard, because otherwise a HP 1 creature suffers negative knockback, which offends me just as much as the DIV BY ZERO error a HP 2 creature gets :D

As previously noted, the RAW says 1 yard per point of damage rolled for ST 3 or less; 3 HP or less in your games. No such thing as negative knockback or DIV BY ZERO errors.

[Polydamas]

Originally Posted by 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.

GURPS can't use HP as a proxy for mass because by RAW the HP of a 150 lb human, a 150 lb zombie (IT: Unliving), and a 150 lb steel ingot (IT: Homogeneous) differ by a factor of four even before you start asking yourself "are these the flimsy kind of zombies or the unstoppable kind?" or "does it have extra HP because its magic steel?"

Ignoring weight carried is an abstraction, especially since carried objects often move differently than body mass.

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.

If you are a brave mathematician, replace ST-2 with 0.8 * ST. If you care enough to add another stat, define a stat to represent mass which is calculated exactly according to the formula for deriving HP from mass in the Basic Set.

[Polydamas]

Originally Posted by Bruno

On topic, we use HP instead of ST, no particular damage done to our games, and we cap it at 1 yard, because otherwise a HP 1 creature suffers negative knockback, which offends me just as much as the DIV BY ZERO error a HP 2 creature gets :D

It is a shame that SJ Games is torn between the buyers who like elegance and consistency, and the buyers who are scared by arithmetic other than adding and subtracting. The former get some cool geeky rules (and TBone's fan site), but the later seem to have more buying power, and they lead to some things which are uglier than they need to be.

I think it was a flat 8 points of damage to 1 yard of knockback in 3rd ed Revised, so the 4e rule is more detailed and logical than what existed before.