Size-to-strength ratios

[RHJunior]

Lord almighty.
I've been hunting all over the web for information on size-to-strength ratios--- trying to find out how much, for instance, a 3-ft tall human should be able to lift vs how much a 6 foot tall human can.... but I've found literally nothing.
Anyone got any leads?

[Psycho42]

Lord almighty.
I've been hunting all over the web for information on size-to-strength ratios--- trying to find out how much, for instance, a 3-ft tall human should be able to lift vs how much a 6 foot tall human can.... but I've found literally nothing.
Anyone got any leads?

My friends call my Psycho,

did you check:
- Guiness Book of Records
- Weightlifting World Records

But I guess you won't find anything about 3-ft tall humans...

Frank

[marknau]

The Square-Cube Law explains why small animals are able to carry many-times their weight, and why elephants can't jump. Strength is proportional to the SQUARE of the linear size of an animal. Mass is proportional to the CUBE of the linear size.

So, all things equal, a 6-foot animal can lift 4x the amount a 3-foot animal can lift. But, since it weighs 8x as much, it is at a disadvantage in performing feats where it is hampered by its own weight.

[dalek_of_god]

Scaling animal characteristics with size is apparently rather complex. The basic (isometric) square-cube laws used to calculate mass and cross sectional area will be misleading when applied to a quality like strength. Some form of allometric scaling will also be required. I don't know what allometric means, other than it came up in size to strength ratio searches. I did manage to find a few sites with some rough data, the best of which was this one. The most pertinant quote:

Strength, as indicated by world records for weight lifting for various body
weight classes,  has been shown by Lietzke to increase proportionally with
the 2/3 power of body mass. This observation is discussed along with many
other scaling issues in McMahon's and Bonner's excellent book, On Size and
Life ( 1983 W. H. Freeman, & Co. ISBN 0-7167-5000-7). I suppose one could
say from this that the "strength to body mass ratio"  is less with
increasing body mass. However, strength is, in fact, increasing as it
should, i.e., proportional to body mass to the 2/3 power. After all that's
the basic notion underlying scaling.

So for the 3' vs. 6' lifting match, the taller individual would have a 2X advantage in height (and also reach), a 2^3 = 8X advantage in mass (if their body shapes are exactly the same), and an 8^(2/3) = 4X advantage in raw strength.

Hopefully this helps.

---
D

[Mike Holmes]

There's only one place to go for htis subject. Sorry all of you above, those are good suggestions, but they just don't compare. The site you need to read if you need information on this and related subjects is to T-Bone's site on IO at:

http://www.io.com/~tbone/gurps/

Look for the stuff labeled Gulliver. This is a 200,000 word (probably more at this point) treatise on the subject of the relationships of size to weight to strength ratios and considerations such as gravity, as they apply to RPGs!. It applies to GURPS, but in looking at it, you can see how one can design rules for any system to accurately handle these things. It even looks like he's put up a lite version so you don't have to peruse the entire work.

Believe me, this is the definitive work on this subject.

Mike

[Ron Edwards]

Hi there,

Hate to burst everyone's bubble about how it's just a size-to-strength thing, but the shape of the limbs and the density of the bones can play a big role as well. Human dwarfs (technically, people who display the condition called achondroplasia) may be very, very strong and heavy compared to people with normally-developed limb bones. I'd hate to arm-wrestle an achondroplasic rather than the other sort of "little person" (I believe "midget" is incorrect), whose proportions are the same as a tall person.

Best,
Ron

[Mike Holmes]

Right Ron. All covered in Gulliver in excruciating detail.

Mike

[RHJunior]

Sweeet. Thanks for the lead !
Heh. Now I can start figuring out how a person's physical size correlates to movement, reach, how far they can jump, physical stamina, etc etc etc....

[Mike Holmes]

What's this for, anyhow?

The reason I ask is that Gulliver is a bit of a White Elephant. I spent a lot of time thinking that the level of realism in simulation that this represents is somehow essential. But I'm better now, thank you.
So, while I can imagine that these concepts could be important to a design, I can also see how they might overshadow something more important. So, I'm a little concerned.

What's the game about?

Mike

[RHJunior]

I'm basically tinkering with an RPG of my comic strip, Tales of the Questor (http://npc.keenspace.com).... while I am trying to keep it from being an overblown overdetailed "combat engine", I did want to avoid any Murphy's Rules in its design.

[Andrew Martin]

I'm basically tinkering with an RPG of my comic strip, Tales of the Questor (http://npc.keenspace.com).... while I am trying to keep it from being an overblown overdetailed "combat engine", I did want to avoid any Murphy's Rules in its design.

Why is it more important to know what a Raccoon can lift, when it's important that the Questor can carry the wooden cage with the little raccoon girl in it? If players knew how much their small, not very strong raccoon hero could carry and knew that a wooden cage with a little Raccon girl would be too much weight, are the the players and their character going to be able to do what the Questor did?

An example of weight lifting: http://npc.keenspace.com/ :)

[Gwen]

While I think that some weight limitations are good in an RPG to keep people from carrying around their entire estate on their backs, I think TOO much detail really bogs the game down quickly.

If I'm going to be toting around in the wilderness, one thing I don't enjoy is figuring my armors weight, the weight of my food, weapons, accessories, etc...  Sometimes I feel like I need some sort of Midieval Texas Instrument graphic calculator just to figure out what my running speed is when I'm carrying ten apples.

When you've written a 20 page dissertation on the square-cube theory between an ant and a weightlifter in an RPG, you've officially crossed the threshold into "taking it way too serious."

Much like in ShadowRun where they developed so many rules for riggers and vehicles and fuel economy...  you couldn't drive a car down the street without breaking into the pre-calc and trying to fly a helicopter when it's running low on fuel?  Ha, good luck.  Hope you brought some graph paper, compass and a book on thermo-dynamics!

Details are good, but try not to take them to the extreme, you know?  I can't get into an RPG if it feels like I'm sitting in a 300 level math course at MIT.

;)

[RHJunior]

Oh, I'm definitely doing my best to avoid over-detail. (Frankly, I'm going back and erasing a lot of the more byzantine details.) In art, detail is nice--- but not if it overwhelms the picture you're trying to present. As I said, I just wanted to get some of the more basic things-- like proportions-- correct, and avoid any obvious bone-ups. (Like the RPG where a normal human character could fall up to 2 stories and suffer no injuries, or the one where a superhero could run 5 miles per hour, when normal human beings run an easy 15 per.... or the one a fully armored human could run as fast as an elf mounted on wolfback... you get the idea.)

As to the strip, 1)the kid in the cage is small 2)the cage is light wood and bindings 3)the main character is running fast enough to run across water-- he's not so much carrying it as pushing it ahead of himself.

[b_bankhead]

What's this for, anyhow?

The reason I ask is that Gulliver is a bit of a White Elephant. I spent a lot of time thinking that the level of realism in simulation that this represents is somehow essential. But I'm better now, thank you.
What's the game about?

Mike

 I have to agree with mike here. I long (by long I mean in the neighborhood of 15 years) stopped regarding this level of obsessive gearheadism about rpgs as anything but an object of fun.  It has been some time since I sat down with Lotus 1-2-3 to plan out a Megatraveler starship since the day I was looking at the Universal task profile and asked myself why the vehicle system couldn't be as blindingly simple,adaptable, and elegant as this?

  So, to be honest I too would steer you away from this monstrosity. Look instead at the material from which it's named. Gulliver,as in Gulliver's Travels.   Swift didnt have the Liliputians eating the same proportionate amount that a mouse dose, or have them jumping about like grasshoppers because that wouldn't have made them a good satirical model for his own society. Likewise he didnt concern himself with fitting the brain of a sentient into a horse's skull because smart horses allowed him to set the vices of humanity off to best advantage ,backlit against the glow of our idealised human potential.

  The Weg Star wars vehicle combat system is a joy to use, yet makes only the vaguest nod to the equations of the revered Isaac Newton.  They could have easily created a monstrosity like 'Gulliver'. Would the game have been better for it?

For my part I would be less interesed in a lot of fancy formulae, and an idea of the purpose size difference is supposed to serve in your game...