Gravity, ST, and Terrans on Mars

[isf]

How does a character's strength change if they are on a world with higher or lower gravity?

Since Mars has a gravity of .38, Earth would have a gravity about 2.5 that of Mars. If I have the ST scale normed for Mars, would I just give Terrans a new ST that has a BL of 2.5 times their BL on Earth? I assume that HP should not change since it is mass based, but shouldn't Terrans be tougher than a Martian of the same mass? If so, how could you model this effect?

[lexington]

Originally Posted by isf

How does a character's strength change if they are on a world with higher or lower gravity?

See the "Different Gravity" rules on page 350 of Basic Set. One thing they don't mention that might be important is MinST for weapons, which should probably scale the same way.

Originally Posted by isf

I assume that HP should not change since it is mass based, but shouldn't Terrans be tougher than a Martian of the same mass? If so, how could you model this effect?

If you want to reflect something like Martians being tall and spindly because of the low gravity give them Vulnerability (Crushing, x2) [-30].

[Dammann]

It is a good question, because on one hand, a martian shouldn't be able to lift as much weight, but should maybe have the same capacity for absorbing damage.

Also, although the strength required to lift a weapon of a certain mass is altered, the strength required to move it around and absorb or alter its inertia would be the same. I am thinking of when I wanted to train with the monk spade, back in kung fu school, many years ago. The test for determining whether a student was eligible for training involved holding the monk spade level with the ground for an interval, which is a fair test of wrist strength. You need to have that for using a weapon that has a 30-40 pound metal weight on the end. I failed to test successfully to begin monk spade training. But I might have actually passed that test on Mars! Then I end up having difficulty keeping control of the weapon during training.

[Stripe]

After reading p. B350, I think you'll agree that Edgar Rice Burroughs' John Carter was a highly-cinematic character.

You may wish to give a Carter-like Superman a little extra ST, but more importantly Striking ST (p. B88). You may wish to give him Tough Skin (p. B47) as well. I've only read the first Barsoom novella, and that was long time ago, but if I remember correctly, Carter could split a Green Martian's skull with a punch pretty easily. IIRC, he killed more than one with his bare hands.

[Fred Brackin]

Originally Posted by Stripe

After reading p. B350, I think you'll agree that Edgar Rice Burroughs' John Carter was a highly-cinematic character.

You may wish to give a Carter-like Superman a little extra ST, but more importantly Striking ST (p. B88). You may wish to give him Tough Skin (p. B47) as well. I've only read the first Barsoom novella, and that was long time ago, but if I remember correctly, Carter could split a Green Martian's skull with a punch pretty easily. IIRC, he killed more than one with his bare hands.

Not a split skull. The Green Martian in question backhanded Dejah Thoris and Carter spontaneously invented the Flying Uppercut leaping straight upward 15 feet and smacking the Greenie in the jaw, killing him either with a broken neck or a fatal concussion.

Actually statting out a Flying Uppercut (which is to a regular Uppercut as a Flying Jump Kick is to a regular Jump Kick) is an interesting exercise in G;Martial Arts but Carter was obviously using some Cinematic rule or other that lets you claim Critical Hits when necessary.

The leaping 15 feet straight up is pretty cinematic too. the reason why it is and the tricky thing if you're actually trying to be realistic is that "weight" or perhaps more properly gravitaional mass varies according to the local field but _inertial_ mass remains the same wherever you go.

The way this translates into Gurps is that Lifting ST manipulates weight but Striking ST (and Min ST for weapons) works on inertial mass. On Earth these are the same according to out locally normed eyes but on Mars they are different.

If youwere really a masochist you could give a human-looking Martian a -4 to Lifting ST but normal Striking ST. A compromise would be to average the two. 38% lift plus 100% striking comes to slightly more than a combined ST of -2 or 64% BL.

This might be okay as Min ST for a Rapier or a Shortsword is 8. HP should be nromal for sT when doing things the simple way or tied to Striking ST when being complex. As humans don't actually have two independant sets of muscles I favor the combination method.

Movement also stays normal as it's largely based on inertial mass. Trazlistically there should be some effect on jumping but that's only because while you can't leap any _faster_ you fall back down more slowly. Potentially very complicated to handle realsitiically.

If I was actually trying to do Barsoom I'd make Barsoomians "normal" and Carter Super-Barsoomian with ST around 30 and 1 or 2 levels of Super Jump.

[sir_pudding]

Originally Posted by lexington

See the "Different Gravity" rules on page 350 of Basic Set.

Seriously. There are already rules for this, there's no need to reinvent the wheel. If you have a specific issue with the RAW, then I can see a reason to address it, but I'm at a loss as to why we need to play "What if I had written the Basic Set".

[isf]

Originally Posted by lexington

See the "Different Gravity" rules on page 350 of Basic Set. One thing they don't mention that might be important is MinST for weapons, which should probably scale the same way.

I had missed that (I was looking in Space and Biotech).

Originally Posted by lexington

If you want to reflect something like Martians being tall and spindly because of the low gravity give them Vulnerability (Crushing, x2) [-30].

I don't know if I'll use this, but I like it.

[vitruvian]

Originally Posted by isf

How does a character's strength change if they are on a world with higher or lower gravity?

Since Mars has a gravity of .38, Earth would have a gravity about 2.5 that of Mars. If I have the ST scale normed for Mars, would I just give Terrans a new ST that has a BL of 2.5 times their BL on Earth? I assume that HP should not change since it is mass based, but shouldn't Terrans be tougher than a Martian of the same mass? If so, how could you model this effect?

I'd just let HP vary with the ST, on the basis that it's not just mass, but how tough and resilient your muscle, bone, and other tissues are as well that determines HP. After all, a ST 20 human doesn't need to weigh in at 1000 lbs; the mass -> HP formula is just a guideline.

If you don't want their Slams and such to work like they weigh a lot more than they do, you can declare any portion of their additional HP you like 'massless', as in not affecting collisions; this would also make falls in Martian gravity less serious for them.

So, if norming ST 10 to be what lets a typical Martian humanoid have a BL of 20 in Martian gravity, that results in a Terran visitor template that looks something like:

ST +6 [60]
Basic Speed +2 [40] (On the basis that Terrans are able to move faster and are used to reacting to things falling much faster)
Super Jump 1 [10] (Together with Basic Speed boost, results in leaps around 3x normal distance)

[David Johnston2]

Originally Posted by isf

How does a character's strength change if they are on a world with higher or lower gravity?

Since Mars has a gravity of .38, Earth would have a gravity about 2.5 that of Mars. If I have the ST scale normed for Mars, would I just give Terrans a new ST that has a BL of 2.5 times their BL on Earth? I assume that HP should not change since it is mass based, but shouldn't Terrans be tougher than a Martian of the same mass?

Honestly? No. The effect of lower gravity would make it possible for Martians to have less mass for a given height or even allow them to be large land invertebrates. But it would not necessarily reduce lifting ability for a given mass.

[malloyd]

Originally Posted by isf

How does a character's strength change if they are on a world with higher or lower gravity?

It doesn't. The weight of things changes on a higher or lower gravity world instead. Your BL stays exactly the same, but the same objects weigh less on Mars, so you don't need as high a BL to lift them. I can't see any reason you would want to go the other way.

but shouldn't Terrans be tougher than a Martian of the same mass? If so, how could you model this effect?

Not for any obvious reason. But if you want them to, just give Martians a -4 racial ST, which allows them to lift about the same objects on Mars humans could lift on Earth, without changing their mass from human normal. Problem solved.

I really think you are trying to scale the wrong thing if you are trying to keep Martians at ST 10.