Where do I find guidelines for relation between ST and weight?

[Fnugus]

For large creatures/races.

Are there any official guidelines for typical relative values of SM, ST, and weight?

[lexington]

Originally Posted by Fnugus

For large creatures/races.

Are there any official guidelines for typical relative values of SM, ST, and weight?

There are semi-official ones in fantasy you can use to scale creature up to larger sizes, but they're unrealistic. I think the reason for the lack of rules is that they wouldn't be generic, different body plans imply different scaling.

GURPS: Gulliver is a good unofficial treatment of the issue.
http://www.gamesdiner.com/gulliver

[whswhs]

Originally Posted by Fnugus

For large creatures/races.

Are there any official guidelines for typical relative values of SM, ST, and weight?

It's more or less in the basic set.

Take the cube root of weight in pounds, and multiply by 2 (for living creatures): That's HP and, if they have musculature, ST.

Divide ST by 5: That's height/length in yards. You can look that up on the SM table. Height 2 yards is SM 0; each x10 height translates to +6 SM. That ST is the appropriate ST for an animal with that SM to be able to move around.

Bill Stoddard

[Anthony]

Realistically it's more like the 0.4 power of weight, at least for lifting ST, due to differences in design at different scales, but it's rare for that to matter much.

[NineDaysDead]

Originally Posted by GURPS Update, page 2

In Fourth Edition, calculate a “normal” massive creature’s ST score based on its mass as follows, rounding down: ST = 2 X (cube root of weight in pounds). Thus, a 1,000-lb. bear has ST 20 and a 16,000-lb. elephant has ST 50. These figures may vary by up to 10% either way to account for unusual individuals.

This message is too short.

[whswhs]

Originally Posted by Anthony

Realistically it's more like the 0.4 power of weight, at least for lifting ST, due to differences in design at different scales, but it's rare for that to matter much.

Yes, quite. The actual scaling is the limb length varies as around the 0.25 power of body mass. But on the scale of most GURPS creatures, the difference between third power and fourth power isn't going to have a lot of impact.

Bill Stoddard

[Fnugus]

Originally Posted by lexington

There are semi-official ones in fantasy you can use to scale creature up to larger sizes, but they're unrealistic. I think the reason for the lack of rules is that they wouldn't be generic, different body plans imply different scaling.

GURPS: Gulliver is a good unofficial treatment of the issue.
http://www.gamesdiner.com/gulliver

This is no less than awesome! I already read through it and made a program to take advantage of all his ideas and notes.

Originally Posted by whswhs

It's more or less in the basic set.

Take the cube root of weight in pounds, and multiply by 2 (for living creatures): That's HP and, if they have musculature, ST.

Divide ST by 5: That's height/length in yards. You can look that up on the SM table. Height 2 yards is SM 0; each x10 height translates to +6 SM. That ST is the appropriate ST for an animal with that SM to be able to move around.

Bill Stoddard

Nice! Seems like I haven't read the Basic Set enough times yet. What page?

[whswhs]

Originally Posted by Fnugus

Nice! Seems like I haven't read the Basic Set enough times yet. What page?

Well, several different ones. You need to look at the Growth advantage on p. B58, at the definition of SM in terms of longest dimension on p. B19, and at the Object Hit Points table on p. B558. I'm not sure there's an explicit statement anywhere that living entities use a 2x multiplier (unliving use 4x, and homogenous use 8x), but it's sort of implied by the overpenetration rule on p. B408.

Bill Stoddard

[Anthony]

Originally Posted by whswhs

Yes, quite. The actual scaling is the limb length varies as around the 0.25 power of body mass.

Which, since limb strength is order 1.5 in limb mass and -2.5 in limb length (assuming constant density), implies that a limb mass that is 4th order in limb length will result in strength that's order 3.5 in scale and 0.875 in mass. I don't think limb mass scales linearly with body mass, though (notably, thicker limbs have flexibility loss).

Originally Posted by whswhs

But on the scale of most GURPS creatures, the difference between third power and fourth power isn't going to have a lot of impact.

It's noticeable on SM 2+ creatures (my 0.4 scaling bumps a 10,000 lb elephant from ST 43 to 56), but considering how much unrelated variance there is in realistic lifting ability (and damage), it probably doesn't matter much.

[Phoenix_Dragon]

Originally Posted by Anthony

Realistically it's more like the 0.4 power of weight, at least for lifting ST, due to differences in design at different scales, but it's rare for that to matter much.

Perhaps I'm misunderstanding what you mean by this, because I'm not getting similar numbers to what you're posting. Like the 10,000lb elephant, scaling by the 1/3 power of its weight and doubling that gets me the proper ST43, but scaling by the 0.4 power of its weight and doubling that gets me ST80, not 56. Is there something I'm missing here?