D6 Gravity?

[Whill]

I'm creating a planet for my game and thinking of making the gravity be somewhat lighter than normal. In looking through D6 Space, I barely found any rules for play in different gravity levels. In Combat Options there's attack modifiers for zero, low and high gravity, but not even any indication what consitutes low and high gravity. I also found a vague reference to movement in normal or standard gravity, implying that move may be effected by different gravities, but no indication of how.

Maybe I'm missing something. If I am, please help me find it. If not, please help me anyway. Any other D6 games talk about various gravity?

And for starters, would you say "standard" gravity is 0.9-1.1 g?

Thanks.

[Rerun941]

I'm creating a planet for my game and thinking of making the gravity be somewhat lighter than normal. In looking through D6 Space, I barely found any rules for play in different gravity levels. In Combat Options there's attack modifiers for zero, low and high gravity, but not even any indication what consitutes low and high gravity. I also found a vague reference to movement in normal or standard gravity, implying that move may be effected by different gravities, but no indication of how.

Maybe I'm missing something. If I am, please help me find it. If not, please help me anyway. Any other D6 games talk about various gravity?

And for starters, would you say "standard" gravity is 0.9-1.1 g?

Thanks.

I didn't find anything giving actual numbers in g. The Star Wars Galaxy Guide: Scouts just refers to Light, Standard and Heavy gravity. Also, I remembered the Orfites from Planet of the Galaxy Vol III. They're a race that is native to a light gravity world. They suffer -1D to Str and Dex on standard gravity worlds when they don't have their special harness.

GURPS defines gravities as micro, low, standard and high. Where each race has its own G-tolerance level. Default for humans is a "native" 1g with a .2g increment.

So, for a human, Standard gravity is .8g - 1.19g. High gravity is 1.2g + and low gravity is < .8g

Different alien species have different native gravities and g increments.

For simplicity, you may just want to go with:
High: > 1.5 g
Standard: between 1.5 and .5g
Low: < .5g

For comparison, the Moon is .166g and Mars is .38g

[Whill]

Thanks for your reply, Rerun.

Anyone have any ideas on all the game mechanics of lower and higher gravities? What all is effected and how?

[Grimace]

Aye. :)

Use increments of tenths. 1.1, 1.2, 1.3, 1.4, 1.5 or in reverse: .9, .8, .7, .6, .5 and so on.

Movement is reduced by the factor or increased by the factor (depending on whether it's heavier than normal or lighter than normal).

So if Move was 10, in a 1.1 G world, Move would be 9. On a 1.5 G world, Mover would be 5. In reverse, on a .9G world, Move would be 11.

Anything from .7 up to 1.3 would work like that. Things above or below would actually start to degrade and require skill checks to be able to move. Like on the moon or whatever. You simply get too light to move quickly and effectively.

Weight works the same way. You weigh 100 kg in 1G. 1.1G you now weigh 110 kg. The stuff you carry may weight 30 kg, but in 1.1G it weighs 33 kg.

Throw range, same way.

Climbing, increase the difficulty just like above. So if you figure climbing a mountainside in 1G would be a 12 difficulty, in a 1.1G world the difficulty goes up to 1.2 (rounded to 1) and becomes a 13. On a 1.5G world you'd add 6 more to the difficulty, making it 18 to climb. On a lighter planet, the difficulty could go down. .8G would reduce the difficulty by 2.4 (rounded to 2) and become a difficulty 10.

As long as you keep everything in increments of tenths, it make addition and subtraction easy.

Jumping worked the same way. Falling, same way. Energy weapons unaffected. Physical weapons may have their ranges reduced or increased depending on gravity. Something that shoots 150 meters would only shoot 135 meters in 1.1G. And only have a range of 75 meters in 1.5G. In light gravity, the same weapon would shoot 180 meters in .8G.

Hope this helps.

[Whill]

Thanks Rerun and Grimace. These responses really help!

[Cryonic]

Weight works the same way. You weigh 100 kg in 1G. 1.1G you now weigh 110 kg. The stuff you carry may weight 30 kg, but in 1.1G it weighs 33 kg.

Just a minor correction. Mass, of which kg is a unit, does not change regardless of gravity. Weight is a measure of force and is Mass * Acceleration (so, Newtons in SI units). You mass 100kg on Earth. You mass 100kg on the moon. Weight in the Foot/Pounds/seconds units seems to change because the same short name, pounds, is used when referring to mass and weight, but are really two different units. Pounds-Force and Pounds-Mass. On Earth, Pounds-Force and Pounds-Mass happen to be the same.

[Grimace]

Well, I was aware of that, but I wasn't going to get that technical. You are correct, though. Your mass doesn't change, only the perceived weight based on the effect of gravity.

I was going for a bit simpler, though.

[Michael Hopcroft]

This raises the interesting question of what effect normal gravity would have on a "Heavyworlder", such as the Hoffmanites of Phil Foglio's series Buck Godot? In the comic, Buck looks alarming rotund and weighs at least four hundred pounds, but in normal gravity he's extremely strong and, for his size, astonishingly agile.

I suspect that a "lightworler", such as someone who's lived their entire life on Mars or the Moon, would face serious problems when they find themselves in normal gravity. In extreme cases they may require mechanical exoskeletons to move or even to stand upright!

[Whill]

Just a minor correction. Mass, of which kg is a unit, does not change regardless of gravity. Weight is a measure of force and is Mass * Acceleration (so, Newtons in SI units). You mass 100kg on Earth. You mass 100kg on the moon. Weight in the Foot/Pounds/seconds units seems to change because the same short name, pounds, is used when referring to mass and weight, but are really two different units. Pounds-Force and Pounds-Mass. On Earth, Pounds-Force and Pounds-Mass happen to be the same.

As always, you are correct, sir. Having a scientific mind and a degree in mathematics, and also being an devout advocate of the metric system, I am well aware that kilograms are a measure of mass, and that mass does not actually change in gravities of various strengths. I was pretty sure that Grimace knew that too. And I even knew what a Newton was. You should be proud: I am such a stickler for accuracy myself that my homemade Star Wars character sheet corrected the "weight" label to "mass", because it doesn't make sense to have a measure of mass answer a question of weight, even though most of my game's characters are going to spend most of their time in 1 G with the miracle of artificial gravity. Anyway, all of Grimace's arithmetic is correct if you add that "In x gravity, mass y has the same weight that z mass would in 1 G."


This raises the interesting question of what effect normal gravity would have on a "Heavyworlder", such as the Hoffmanites of Phil Foglio's series Buck Godot? In the comic, Buck looks alarming rotund and weighs at least four hundred pounds, but in normal gravity he's extremely strong and, for his size, astonishingly agile.

I wanted basic game mechanics for gravity, but this is the type of stuff I was also thinking about. Rerun answered with an example I can look up of species from a lighter gravity world needing a special harness or suffering a penalties to Str and Dex. I would think that a species from a lower gravity would already have a lower base STR because the stats of made for a default of 1G (or should be). So I'll read about the species but I'd probably give them a low STR in the first place and no penalty on STR in standard gravity. But Dex seems to be effected in a different gravity (higher or lower), so I can see the Dex being effected because the gravity is so alien and a difficult adjustment.

I don't think I will make the gravity too much lower on that planet I am designing because I don't want the indiginous species to be so effected on 1 G worlds (Dex is very important to one of them).

D6 Space has a generic heavy gravity worlder package, and D6 Space Aliens has a specific species with a full write-up. They are short, stout and strong, but suffer a -1 pip on all Agility rolls in normal gravity.

[Michael Hopcroft]

D6 Space has a generic heavy gravity worlder package, and D6 Space Aliens has a specific species with a full write-up. They are short, stout and strong, but suffer a -1 pip on all Agility rolls in normal gravity.

That seems odd -- after a short adjustment period they should have nomral or even improved agility and dexterity because it's easier to move their now-lighter bodies.

And pity the person born and raised in microgravity. Land them even on Mars and they have such serious issues that their very survival is in doubt.

[Cryonic]

That seems odd -- after a short adjustment period they should have nomral or even improved agility and dexterity because it's easier to move their now-lighter bodies.

And pity the person born and raised in microgravity. Land them even on Mars and they have such serious issues that their very survival is in doubt.

Only if they have readjusted to the lower gravity. Think of it like gaining your sea legs. When you first get on the boat and it is moving on the water, your coordination gets off as your mind isn't used to compensating for the motion of the boat. Same thing here. Heck, look at the initial footage of the astronauts on the moon. It takes them a small bit of practice to deal with the lower gravity and to pull back on their strength that they normally use to just walk, heheh.