[Greyspace] The Grinder

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Big Mac
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[Greyspace] The Grinder

Post by Big Mac » Mon Sep 26, 2016 12:22 pm

A while ago, I looked at The Tears of Selune to see how many asteroids there should be (and how many asteroids of each size there should be). I'd like to do the same for The Grinder.

Page 27 of SJR6 Greyspace says there are "countless millions of asteroids, planetoids and planetesimals, ranging in size from about 100 miles in diameter (Size B) down to the size of golfballs", but that "the vast majority of the bodies fall into the middle of this spectrum, with the average object being several tens of yards across".

I don't think I recall a "proper" definition of "asteroid", "planetoid" and "planetesimal", but I'd be tempted to go with this (unless someone has a canon source to point me at:
  • Asteroid = a small irregular celestial body with a gravity plane,
  • Planetoid = a small regular celestial body with single-point gravity (like a small planet) and
  • Planetesimal = a celestial body that is so small that it does not qualify as either an asteroid or a planetoid.
I'm not sure that planetesimals would be objects that don't generate a gravity plane, hold an atmosphere or cause spelljamming ships to drop out of spelljamming speed, but I suspect that they might be that small.

EDIT: From the other stuff I have read, it seems that Nigel Findlay was trying to introduce a minimum size of 1 mile into the Size A category (something I don't think it originally had) and that planetesimal means any object smaller than a Size A celestial body. But that's a guess.

Then, despite being told that the "average" objects in The Grinder are "several tens of yards across" we get some numbers on the larger asteroids/planetoids that seem to be a bit on the small side:
[b]Size[/b]|[b]Number of asteroids/planetoids[/b] 10-100 miles in diameter (Size B)|not more than 200 1-10 miles in diameter (Size A)|perhaps 100,000

I'm not sure if Nigel Findley meant average or median, when he said spoke of "several tens of yards across" and we have the same "what does several mean" issue that we had with the Tears of Selûne, but I think the number of Grinder objects smaller than 1 mile comes down to this equation:

Objects less than 1 mile in diameter = "countless millions" - (100,000 + 200)

Effectively, it's going to be so little different to "countless millions" than it probably does not matter in statistical terms.

I think this leaves us with working out how many asteroids are more than "several tens of yards across" and how many are less than "several tens of yards across". And I think that comes down to this equation:

Objects larger than "several tens of yards across" = objects smaller than "several tens of yards across" = ("countless millions ÷ 2)

We are still left with a number that is so large that it effectively meaningless in game terms. (I'm sure someone, better at maths than me, could plug some numbers into the A = 4π r² formula and work out some numbers for the distribution of asteroids in a specific section of The Grinder, but I'm not quite sure where to proceed at the moment.)

I'm figuring that we are most probably going to need a random encounter table, for The Grinder that gives us "objects larger than several tens of yards across" almost half of the time (where the ship can land or avoid those objects) and "objects smaller than several tens of yards across" (which pretty much work in a similar way to missile attacks on the ship).

For the small number of times that we don't have a ship encounter an object in the "several tens of yards across" to one mile range, or a hit on the ship (or near miss) from a small object, we could probably have a sub-table that either gives us an encounter with a Size A asteroid, a ship, a wildspace critter or one of the small number of Size B asteroids.

I'm not quite sure yet, if the "less than one mile" objects should be subdivided a bit more (in a half-and-half spread) with ships being able to avoid "ramming attacks" from objects that are round about ship size, as well as having some fun descriptions of clusters or rocks tearing at sails or canonball-sized rocks bouncing off of the decking and causing NPCs to save to avoid being knocked overboard.

I am also wondering if travelling faster than SR = 1 (TR = 1) would make things more dangerous in The Grinder.

Does anyone have any thoughts here?

If I can get some options that I am happy with, I might edit this first post and add a poll. (But this is mostly for me to get feedback from you lot. I don't expect other people to play the same way as me.)

Known Asteroids in The Grinder

I'm editing my first post to add an alphabetical list of the known Tears of Selûne (as well as links to discuss individual Tears):
[b]Name[/b]|[b]Source[/b] Ceres (aka "the Pup")|[i]SJR6 Greyspace[/i] Khadazah ("Motherload")|[i]SJR6 Greyspace[/i] Lassh'tz Zst'q ("We are here")|[i]SJR6 Greyspace[/i] [url=http://www.spelljammer.org/worlds/Greys ... s.Pearball]Pearball[/url]|[i]Spelljammer: Beyond the Moons[/i] (fanon) Reaper (aka "the Graveyard" or "Charnelhouse")|[i]SJR6 Greyspace[/i] The Rock of Bral*|various Skullbringer|[i]SJR6 Greyspace[/i] unnamed former beholder colony|[i]SJR6 Greyspace[/i] second unnamed former beholder colony|[i]SJR6 Greyspace[/i]

* = The Rock of Bral was given several optional locations in the AD&D Adventures in Space boxed set, one of which is within The Grinder. Late SJ sources placed Bral in its own crystal sphere, while some FR sources placed Bral in The Tears of Selûne. YSJDMV
David "Big Mac" Shepheard
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ripvanwormer
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Re: [Greyspace] The Grinder

Post by ripvanwormer » Tue Sep 27, 2016 12:20 am

  • There's supposed to be one or more Chainman bases in the Grinder (mentioned in The Complete Spacefarer's Handbook, page 91).
  • The Smiths' Coster is based on a dwarven citadel in the Grinder (The Complete Spacefarer's Handbook, page 88). Maybe this is Motherlode, but perhaps it's a different one.
  • The Scavver-Breeders have taken over "a large portion" of the Grinder (The War Captain's Companion, War Captain's Guide, page 27).
  • Atropus has no canonical position in Greyspace, but the Grinder seems likely if it isn't currently threatening a world. It may be responsible for the disaster on Charnelhouse.
Greyspace wrote:"Ranging in size from about 100 miles in diameter (size B) down to the size of golfballs."
So nothing, or very little, bigger than size B.
Greyspace wrote:There are perhaps 100,000 size A bodies (those between one and ten miles in diameter).
This sounds like clear indication that they're counting anything less than a mile in diameter as not a class A body. The vast majority, as they say, are less than 300 feet in diameter.
Greyspace wrote:"The larger asteroids—those with a diameter of a mile or more—usually have breathable atmospheres, although there are some exceptions. Smaller rocks are generally Voidworlds, although there are exceptions here, too."
So mostly only the 100,000 size A bodies and the 200 size B bodies will have atmospheres. However...
Greyspace wrote:"The vast majority of these bodies fall to the middle of this spectrum, with the average object being several tens of yards across."
I'd say that the important word here isn't "several," but "tens." Tens means less than 100. So a typical asteroid in the Grinder is less than 100 yards (300 feet, or 91.44 meters) across. Whether "several tens" means 150 feet or 210 feet is cutting it a bit too fine: it isn't more precise than that because it doesn't matter. It's less than 300 feet across. Not very big, then.

Significantly, though, this is about three times as big as the minimum size for most spelljamming vessels (Concordance of Arcane Space, page 7). It'll be easily big enough to carry enough air for passing spelljamming ships to refresh their own envelopes (particularly because a rocky asteroid is more massive than a typical ship, dwarven citadels aside). Some of them might be already exhausted, or voidworlds, but all of them should be able to hold air if air is available, or can be brought to them. Assuming that most asteroids in the Grinder are roughly the size of a dwarven citadel (which are 250 feet by 200 feet, so they fit the description of "several tens of yards"), that'd make them about 300 tons, good enough for some 1200-2400 months of travel.

A mile is 5280 feet, or about 20 times the length of a dwarven citadel. A golf ball is 1.68 inches in diameter, or about a 1786th the length of a dwarven citadel. I'd assume that very small or very big asteroids in this range are very rare (since the "vast majority" are somewhere in the middle of the range), and most are approximately dwarven citadel-sized.

One convenient way to measure asteroids less than size A might be to use 3e creature sizes, though Colossal is only about half the size of a dwarven citadel. The d20 Spelljammer rules from Polyhedron #92 added another size category beyond Colossal: Awesome, which is for ships more than 128 feet long. If we assume that an average asteroid is Colossal in size, that still leaves some ranks in between that and a size A asteroid, but try this.

Roll 1d20.

On a roll of 1, roll 1d10:
1 Fine (6 in. or less)
2 Diminutive (6 in. to 1 foot)
3 Tiny (1 ft to 2 ft)
4 Small (2 ft to 4 ft)
5 Medium (4 ft to 8 ft)
6 Large (8 ft to 16 ft)
7 Huge (16 ft to 32 ft)
8 Gargantuan (32 ft to 64 ft)
9 Colossal (64 ft to 128 ft)
10 Awesome (128 ft to 256 ft)

On a roll of 2-19, the asteroid is roughly the size of a dwarven citadel (250 feet). Maybe 200+1d100.

On a roll of 20, roll 1d20 again:
1 Asteroid is the size of a dwarven citadel (250 feet)
2 Asteroid is twice the size of a dwarven citadel (500 ft)
3 Asteroid is three times the size of a dwarven citadel (750 ft)
4 Asteroid is four times the size of a dwarven citadel (1000 ft)
5 Asteroid is five times the size of a dwarven citadel (1250 ft)
6 Asteroid is six times the size of a dwarven citadel (1500 ft)
7 Asteroid is seven times the size of a dwarven citadel (1750 ft)
8 Asteroid is eight times the size of a dwarven citadel (2000 feet)
9 Asteroid is nine times the size of a dwarven citadel (2250 feet)
10 Asteroid is ten times the size of a dwarven citadel (2500 feet)
11 Asteroid is eleven times the size of a dwarven citadel (2750 feet)
12 Asteroid twelve times the size of a dwarven citadel (3000 feet)
13 Asteroid is thirteen times the size of a dwarven citadel (3250 feet)
14 Asteroid is fourteen times the size of a dwarven citadel (3500 feet)
15 Asteroid is fifteen times the size of a dwarven citadel (3750 feet)
16 Asteroid is sixteen times the size of a dwarven citadel (4000 feet)
17 Asteroid is seventeen times the size of a dwarven citadel (4250 feet)
18 Asteroid is eighteen times the size of a dwarven citadel (4500 feet)
19 Asteroid is nineteen times the size of a dwarven citadel (4750 feet)
20 Asteroid is twenty times the size of a dwarven citadel (5000 feet)

That's almost, but not quite, size A. There are only 100,000 size A asteroids in the Grinder, so you probably won't encounter one randomly. PCs will have to find one on a map and go there deliberately, or be guided there. If you really want to simulate the chances of finding one randomly, then if you've rolled 20 twice to find a 5000 foot asteroid, roll again. If you've rolled a 20 three times in a row (chances: 1 in 8000) assume the PCs have randomly found a size A asteroid.

If it's not a size A asteroid, assume a 1 in 20 chance the asteroid has an inhabitable atmosphere anyway.

You can roll on the random charts in the Spelljammer boxed set to determine the asteroid's elemental composition and shape. Some might be flatworlds, elliptical, cubic, amorphous, etc. You can roll on the "goodies" chart to determine if the asteroid has another asteroid functioning as a moon, or a perhaps even a ring.
Concordance of Arcane Space, page 7 wrote:"Celestial bodies extend upward in size to that of the sun, and downward to the size of asteroids and planetoids... In general, however, a celestial body is a planetary mass. Most have a regenerating atmosphere."
I read this as saying that most celestial bodies the size of planetoids or bigger have atmospheres that can regenerate. Probably it depends on whether or not the planetoid has plants on it, perhaps just moss and lichen. The Grinder might have seeds and spores that float between planetoids, sprouting to life on anything with water and air. There could be clouds of water moving between planetoids as well. Some asteroids will probably made out of ice. Some might be made out of water, fire, air, or other more exotic substances.
Big Mac wrote:I am also wondering if travelling faster than SR = 1 (TR = 1) would make things more dangerous in The Grinder.
Yes. Greyspace says that "the only sane thing for a captain to do is slow to tactical speed when the vessel reaches the outer margin of the Grinder." If they choose not to, the odds are just barely in favor of them making it through anyway. So perhaps we should say, in 3rd edition terms, that the captain needs to make a navigation roll at DC 9. Rolling a 9 or above means the ship is safe. 2-8 means the ship is forced to tactical speed anyway as it goes too close to an asteroid. A roll of 1 means the ship smashes into an asteroid.

ripvanwormer
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Re: [Greyspace] The Grinder

Post by ripvanwormer » Tue Sep 27, 2016 2:46 am

I updated the above with random size charts. I gave only a 10% total chance that the asteroid is either bigger or smaller than standard. What do you think, should it be more? I think you could double (or more than double) the chances of finding a smaller one while leaving the chance of finding a bigger one the same. Bigger ones should be rare.

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