PC's from low gravity worlds

[Supplement Four]

I've been tinkering with an idea for a campaign, and I've been looking for place to set it. Alell (Regina subsector) came up in a post I wrote recently, and the characteristics of the world intrigued me.

Then, I saw that Heaven & Earth has an update that I don't have, so I downloaded it. And, I've been playing around with it.

World gravity seems to be something that is almost ignored in CT. Characters who spend their whole lives on a low gravity world, then venture out into space, seem to have no problem operating in the various G fields presented by various worlds.

As I looked at Alell through the eyes of H&E, I saw that the Size 4 world has a G field of .47 Gs.

And, I started thinking....

Remember reading Arthur C. Clarke's Imperial Earth, where the main character, from Titan, had to prepare himself for months by wearing a harness with lead bars everywhere he went in order to strengthen his muscles in prep for Earth's gravity?

Hmm...

What about paying attention to that in a Traveller game?

(My gawd, the ramifacations for things we don't normally think about--think about inductees into the Imperial Navy! Do naval enlistees from low gravity worlds go through months of training to prepare them for a standard 1G? Or, are Naval ships all crewed with people from like backgrounds? "You don't want to go aboard INTREPID. That ships is crewed with the high Gers. You'll be out of breath before you make it to the bridge.")



For example, characters from Alell, used to the .47 G gravity, can easily adjust their ship's G plates to suit them. But, what about this be a guiding factor during the game?

It'll be hard for them to move on standard-G and high-G planets, so the crew may avoid them.

Imagine that. They'll actually look for Size 4 worlds on which to trade.

It can turn into an in-game project for the crew slowly crank up the ship's G rating, over weeks and months, to get their muscles up to speed for a standard G world.

Might make for interesting gameplay.

The devil is in the details.

(Things I never thought about when I was in my teens playing Traveller.)

 

[aramis]

I did... I used the tables from Judge's Guild's Traveller Logbook.

Later I used the 2300 Rules which do consider it somewhat.

 

[Supplement Four]

I did... I used the tables from Judge's Guild's Traveller Logbook.

The logbook doesn't do anything but adjust initial dice for the gravity on a character's homeworld.

I'm talking about the effects on a person from a .5 G world who travels to a 1 G or 1.5 G world. It could be a large factor in where you ship makes port.

Sure, if the high port is available, then problems are minimal. But, low tech worlds with downports only might be something a person from a .5 G world would consider.

The whole military issue I bring up above interests me too. Recruits into the Navy have to either go through some type of muscle training if they're from a low G world, or the Navy groups people from like homeworlds together on ships--where conditions on the ship can be managed.



This gravity issue is much bigger than Traveller has ever given it credit for. If you think about it, there should be gravity requirements for Marines (they prefer recruits from Size 8 worlds).







EDIT:

The rules for different gravity in CT are written from the point of view of a character from a 1 G world. A character can carry a heavier load when on a Size 4 world than when on a Size 8 world.

The rule (and chart) need to be adjusted if a character is from a .5 G world. (Load capacity is halved on a Size 8 world, etc.)

 

[atpollard]

From NASA research, many people will die under a prolonged exposure to 2 Gees since their heart and veins will not be able to pump blood up to the brain. (direction is critical since this applies to 2 G from head to toe, but 2 G front to back can be tolerated indefinately.)

In Traveller, this begs the question of how long those people have been living at <0.5 Gees and how have they adapted physiologically. In your example, a 1G world could mean death in minutes for your Low G merchant.

Perhaps he would need to wear a Gee suit to push the blood back up in the higher gravity.

 

[Supplement Four]

Perhaps he would need to wear a Gee suit to push the blood back up in the higher gravity.

I would think equipment like this would be necessary (and maybe fairly commonplace).

How long have people been living on Alell? A thousand years? How long have people been living on any of the Size 4 worlds in the Imperium?

Pysadi?

I never did finish reading Imperial Earth (I will one day), but Clarke is known for his science, right? And, Titan is something like 0.17 Gs. I don't know much about it, but it seems that living in a low G environment may not be impossible (but I have seen the Zero G research where bones start to become brittle and some muscles atrophy, etc).

What do you think a person would be like (physically) who's lived his whole live in 0.47 Gs?

Is this possible?







EDIT:

Doesn't it seem that there should be a big modifier when dicing for passengers from a world that has a smaller size code than the destination world? Any leftovers could be transient traffic on one leg of their journey, but, for most people, there's got to be a real reason to go to another world with the gravity there is twice what you're accustomed to experiencing.

 

[far-trader]

I've mostly ignored it. People living on extreme gravity worlds generally live with artificial gravity compensating. Same for people travelling and living in space and living on asteroids.

It's always been in the back of my mind for when players visit lower TL (below 8 generally) worlds, poor worlds (can't afford fancy gravitics everywhere), and backwater ports (TL 7 and less with starport C and less) where you probably won't even have arti-g at the port.

It's in the rules, under the weight carry adjustment, which is the main factor to consider for brief periods of exposure. Prolonged exposure is a different matter.

I have pondered, given the world creation rules, if Vilani weren't adapted to a slightly lower gravity (world size 7 and 0.875g) being the average. Leading to them looking favorably (i.e. roll 2d-2) for size 7 worlds. And if that's the case perhaps generating Solomani worlds as (2d-1) favoring size 8 worlds. With Vilani arti-g being set at 0.875g while Solomani is set at 1.0g. Just for some variety. The difference would be enough to be noticed but not uncomfortable.

As for adjusting passenger rolls, nah, 'Travellers' are the exception, not the norm. They will already be standard gravity adapted if not born to it, except in rare cases to promote the plot.

And wearing a lead weighted suit to adapt to high g seems unlikely to work (1), despite the source of the story (2), and positively antiquated and low tech in a game universe with arti-g. Just have the computer adjust the gravity gradually to adapt. If you allow fine control of arti-g in your TU.



(1) Will I become adapted to low g if I wear balloons attached to my body? While walking around on Earth? Will I experience zero g if the balloons are enough to lift my weight? I don't think so.

(2) I wonder when you ask "Clarke is known for his science" if you're thinking of Asimov? Clarke, while well grounded in science was more about the story and I think if the plot required it he was willing to suspend belief and soften the science. Asimov was more the hard sci-fi writer. If memory serves, and it does so with more reluctance and error daily

 

[Supplement Four]

It's in the rules, under the weight carry adjustment, which is the main factor to consider for brief periods of exposure. Prolonged exposure is a different matter.

It's in the rules from the point of view of a character used to 1G. At .5 G, he can carry more. At 1.5 G, he can carry less.

For a character used to .5 G, it'd be a different story. At 1G, he's struggling. At 1.5 G, he's really struggling.



EDIT:

Maybe the STR and END DMs presented in the Traveller's Logbook should be used, and the load rules for use in different gravity need to be adjusted for the switch in point of view.

 

[Fritz_Brown]

This thread is why it wasn't made a rule in CT. Seriously, the concept seriously cramps the whole point of Traveller: travel around in a starship - trading, fighting, pirating, whatever - wherever the game takes you.

Having said that, let me "correct" one thing: size of the world isn't the only determinant of gravity. I know, CT seems to only take that into account, but it's not realistic. For instance, the Earth is more dense than Mars (about .7 Earth's density) - a major reason for the gravity difference. So, a small planet could conceivably have a more normal gravity, with a larger planet being less than 1G.

This is all predicated on the composition of the planet - which is why CT doesn't get into it. A nickel-iron planet (not just the core, but the whole planet) would be very dense - but it would also have no magnetic field to speak of (probably), and wouldn't lend itself to agriculture. It might have a suitable atmo, though. (Would the planet be in a constant state of rust?) A planet consisting mostly of lighter elements would tend to a thinner atmo, and less gravity.

I have been trying to correlate the atmo ratings to size to figure out gravity. I haven't had much success yet - but that could be because I'm not working very hard at it.

As for PCs, have you read Bujold's book about "quaddies" (Falling Free)? They are genetically engineered to be adapted to micro-G. (The story revolves around their being considered company property because it "created" them.) They have a difficult time in any kind of sustained G-field. Read that book for some good ideas.

 

[Supplement Four]

Having said that, let me "correct" one thing: size of the world isn't the only determinant of gravity. I know, CT seems to only take that into account, but it's not realistic.

A little credit, though...CT does say that standard Earth density is assumed for simplicity.

And, DGP published Grand Survey for CT, which will allow you to determine the density of your world (and the core and gravity field, etc)...if you want to get that detailed.

I have noticed that assuming a standard Earth density works pretty well, rounding numbers, if you base gravity on size. It's a good rule of thumb, and that's what you need in CT.

Otherwise, you're playing clunky TNE.

 

[BlackBat242]

As for PCs, have you read Bujold's book about "quaddies" (Falling Free)? They are genetically engineered to be adapted to micro-G. (The story revolves around their being considered company property because it "created" them.) They have a difficult time in any kind of sustained G-field. Read that book for some good ideas.

Have a basic write-up for them in my TU...


And for Heavyworlders (based on Anne McCaffery's books).

 

[Icosahedron]

I'm guessing here, but I reckon adaptation takes time - lots of it. Yes, a character from a low G world may develop weaker muscles (which could be trained over a period of months/years) but I'm not so sure his heart and veins would be deficient. Those things are not so genetically capricious as things like height and weight. Much of our bodies' design is genetic, and if your ancestors were from a 1G world, I think you could 're-adapt' fairly quickly.
Similarly, you might become tolerant to an atmospheric taint, but that doesn't mean you would suffocate if that taint were removed. Re-adaptation to standard G would not be as easy as to standard atmosphere, but I think there would be a strong element of genetic tolerance to 'ancestral standard'.

If you add in the 'universal genetic mods' (all characters have them, don't they? That's how humans conquered the universe isn't it?) and grav compensated buildings/streets to keep things as near to 1G as possible, characters shouldn't have too much difficulty adapting - at least to the point of not dying, clotting, crumbling or wasting away.
Make 'em work, but don't make 'em die.

 

[coliver988]

Heinlein's The Moon Is A Harsh Mistress took low grav into account as well: pretty much anyone born on the moon (a penal colony) could barely go to Earth: living in what was to them 6G made just breathing hard.

Of course, who really knows the reality of it: how much genetics actually play into things for determining how well you adapt to higher gravity. We never considered home world stuff back when I actually played the game rather than just played at the game, so the gravity stuff really never came up.

 

[atpollard]

I'm guessing here, but I reckon adaptation takes time - lots of it. Yes, a character from a low G world may develop weaker muscles (which could be trained over a period of months/years) but I'm not so sure his heart and veins would be deficient. Those things are not so genetically capricious as things like height and weight. Much of our bodies' design is genetic, and if your ancestors were from a 1G world, I think you could 're-adapt' fairly quickly.

For the second or third generation, I agree 100%.

What about those Traveller worlds that have been settled since the First Imperium? Is 5000 years of genetic adaptation enough to create problems?

Are there any Human populations transplanted by the Ancients to low grav worlds? Is 100,000 years of genetic adaptation enough to create problems?

PS. This is just for the sake of theoretical discussion, Characters being killed by a 'High G' world because they are from a 'Low G' world would add absolutely no fun to the game.

 

[Thuban]

I think this is interesting and useful as a plot device involving patrons or other NPCs, but it's not a limitation with which I'd saddle the player characters.

The adventurers are the quintessential Travellers, and in the course of their prior careers they acquired the necessary conditioning to function effecitively in higher or lower gravities. I can see this as a function of basic training for Navy, Scout, Marine, and Merchant characters for certain, and probably for Army characters as well - consider that conditioning for off-world deployments is one of the elements that separates lift-qualified units from non-lift units ("All right, maggots, listen up. This deployment will be a 1.2 Gs, so that's two hours of extra PT daily and the doc will have your calcium-enhancement meds at 1700 . . ."). This also helps to explain why so many adventurers come from these careers.

The CotI prior careers may seem less likely to be candidates, but again, it's not something I would expect the adventurers to deal with - at some point in their background they received conditioning that makes them able to function within normal limits as determined in Book 3. I also don't impose penalties on the adventurers for technology higher or lower than that of their homeworlds - it's handwaved for player characters for the most part, but serves as a useful plot device for NPCs.

 

[Supplement Four]

I think this is interesting and useful as a plot device involving patrons or other NPCs, but it's not a limitation with which I'd saddle the player characters.

The solution is to have all player characters come from Size 8 worlds (or bigger). Those guys don't have as much trouble going around the universe.

It's the characters from Size 4 worlds (and smaller) that have an issue. If they go to a Size 10 world, things are very hard on them (and a hindrance for those from a Size 8 world).

Living on a Size 4 world is a jail sentence to never leave that world.

Now, I was looking at Alell (the planet that started this discussion), and although it's a small world, it's damn cold there. Something like -137 degrees F (with a std atmosphere).

Well, if it's that cold. And, the TL of the world is TLD. There's no reason not to assume that all locations on that world take place in-doors, and all buildings use grav plates, just like a space station or a starship.

It's the low tech Size-4 worlds that can be a beech. (Check out Pysadi in the Aramis subsector--Size 4 and TL 4, with a Class C starport.)

In my last campaign, Pysadi was an option (the worst option, depending on the lowest roll) as a PC homeworld. I reconned that PCs from that world were somehow associated with the starport (and its 1G field) rather than the native population of the planet.

 

[far-trader]

Ah yes, that silly (imo) TL -2 for Gov D.

Though even without that, TL 6 would be sucky for anything but an earth standard world. But, it is an Ag world so we can presume moderate temperatures, and 0.5Gs doesn't seem all that bad even for long term (generations) residents. I don't think it would be a prison sentence and I doubt they'd have evolved much to adapt to it. They'd probably be more easily fatigued in standard gravity but no more so than somebody carrying around twice the average body weight, and face it, there's lots of obese people doing just that. Those who were athletic at home on Pysadi wouldn't be the first pick for sports under standard g.

The most likely thing would be early onset osteoporosis which on a light g world wouldn't be as serious as standard g.

But that's just one take on the matter.

Far more serious than all this talk of can a native of Pysadi walk unaided on Regina is can a small world with low gravity hold onto a standard density oxygen atmosphere

Besides, the government of Pysadi isn't going to let one of the faithful leave anyway :smirk: Now, if the PCs kidnap one of the flock...

I do like the discussion, lots of idea spawning thoughts.

 

[Icosahedron]

Still guessing, ATP, but I think 50ka to 100ka as a minimum would be the sort of time-span for a genetic branch to burn its bridges in terms of its basic survival package - unless any biologists out there know different?...

Thuban, yes, Travellers need to travel and gene mods or other conditioning to allow this is a background assumption IMTU. I'm not going to limit interstellar travel to residents of Size 8+ worlds, nor am I going to kill PCs just because they come from a small planet. (unless they're stupid as well :devil
However, if they've been living there a while they'll be hard-pressed to move about on a higher G world; muscles atrophy pretty quickly - ask anyone who has just removed a long term leg plaster...

 

[rancke]

World gravity seems to be something that is almost ignored in CT. Characters who spend their whole lives on a low gravity world, then venture out into space, seem to have no problem operating in the various G fields presented by various worlds.

Newer rules sets do take gravity into account. GT:First In has rules for determining gravity and for relating it to world size and atmosphere density.

As I looked at Alell through the eyes of H&E, I saw that the Size 4 world has a G field of .47 Gs.

Which I believe would make it impossible for it to have retained a standard atmosphere. I recently wrote up Alell (very briefly) for a JTAS Online article[*], and I gave it a gravity of .67 (of course, I had to give it an outrageous density to do that).


[*] Not canon, of course.


Hans

 

[rancke]

Now, I was looking at Alell (the planet that started this discussion), and although it's a small world, it's damn cold there. Something like -137 degrees F (with a std atmosphere).

Where did you get that temperature? Behind the Claw claims that the temperature is Normal.

Well, if it's that cold. And, the TL of the world is TLD. There's no reason not to assume that all locations on that world take place in-doors, and all buildings use grav plates, just like a space station or a starship.

There's an amber zone in The Traveller Book called Exit Visa that's set on Alell. It has a 24 hour day (probably not exactly 24 hours) and ISTR that it is described as a perfectly normal world, but that may just be a lack of any references to non-normal parameters.

The canonical star class (M7 V) has to be wrong, since that would make Alell tide locked.


Hans

 

[atpollard]

I recently wrote up Alell (very briefly) for a JTAS Online article[*], and I gave it a gravity of .67 (of course, I had to give it an outrageous density to do that).

It's all the fault of those careless Ancients! Alaways leaving their lumps of star cores floating around space, attracting all sorts of loose rock and dirty snowballs. Before you know it 'BAM' you have another tiny world with an atmosphere.

I hate it when that happens.