Books used: Stars Without Number core, Dead Names, Hulks & Horrors, maybe a little bit of Silent Legions.
Step 0: Basic Principles
Do not be a slave to the tables. Tables are for inspiration and randomization, they aren't a substitute for creativity and they aren't a straightjacket. Reroll results you don't like. If you're rolling on three D10 tables, roll 3d10 and assign the results as you see fit. Skip tables if you're getting enough detail; Dead Names especially can tell you more than you need to know.
Also, I have certain biases that affect how I interpret the tables, so I'll talk about them some as we go. I don't think 1 in 8 systems should be a black hole, for example, so I reroll stuff like that and use it if I hit the same roll again. (This is similar to the Double Dragon house rule in B/X, where if you get a dragon as a wandering monster you reroll, and use a dragon if it comes up again.)
My personal campaign is, I think, a lot more low-rent than the standard. The Mandate wasn't quite as powerful or as wide-ranging. The Scream was more destructive to technology, not just human psychics. The fall was really hard. A lot more colonies died out or reverted to lower tech levels. There weren't really scavenger fleets keeping communication alive. Things are just now starting up after rediscovery of the spike drive, and the PCs might be the first to visit a new system in centuries.
Step 1: Basic System Geography
I start with Hulks & Horrors. I don't like H&H much in terms of the game rules, but it has really neat layout in places and some tables that can be useful. I might post some of those later.
First, we figure out what kind of star is at the center of the system. We roll a d6 and get a 1 (H&H 72), so it's a normal system with only one star. I personally think that H&H's tables need to be more heavily weighted so that you don't get so many binary and trinary star systems, and so many other odd results, but you could always just roll 2d6 and take the lower. I then roll two sets of percentile dice (H&H 74), pick whatever two results please me the most from those two bands, and name it Betelgeuse Q. I think it's important to make system names that kind of roll off the tongue. You don't want it to be too awkward for your players to say.
So, what's going on in Betelgeuse Q?
First we roll for star type: 1d8 on p. 75. We get a white dwarf.
"White Dwarf – Collapsed dwarf stars that have cast off their outer layers as a surrounding planetary nebula, leaving only the very small, dim ball of cooling plasma at their center. Worlds around them are often rather cold, and even in daylight the stars still shine around it and the sky is very dark."
That's great. I personally like having older, dimmer stars. I think it gives the campaign a sense of long and forgotten history. Like the galaxy is winding down and the current players are building tiny, vibrant kingdoms in the wreckage of empires that would overshadow everything that will ever be accomplished again. Sort of like the Dying Earth books, I suppose.
Now, we get 2d6 objects orbiting the central star. There is a system for determining how many AU out they are, but I don't use it because it isn't pertinent to SWN's rules. I roll 2d6 and get a seven - so that's how many major objects there are.
Now I determine their types, with a 1d10 roll for each object: 2, 3, 4, 4, 7, 8, 9. Those rolls aren't in order; instead of taking the order as given I assign it later in the process. Using the system on H&H p. 76, that comes out to two terrestrial worlds, two gas giants, one dwarf planet, one belt, and one deep space station. That should be room for plenty of places for the PCs to do stuff.
We'll start with the Terrestrial Worlds, which means planets that are roughly earth-like in size. There are ten basic types, with variations for atmosphere and gravity. One is a low-g Gaia world (this means it has a lot of native life and different climates) with a CO2 based atmosphere. That's a potentially interesting hook, there. It can't support unshielded human life right now, but if you seeded it with plants that would convert CO2 to oxygen you might be able to terraform it. We should keep that in mind, especially if there's intelligent native life.
The second terrestrial world is a forest world. It's covered in deep forests, lots of wildlife, lots of fog. Medium gravity, oxygen-based atmosphere. We're going to come back to both of these places!
Now for the Gas Giants. These are typically boring of themselves, but they can have interesting moons. Gas giants have a type, a gravity, and an atmosphere content. You can't land on any of them, so I think they aren't very interesting. Incidentally, my read on gas giants is that "low" gravity means low for a gas giant. It's still going to be much higher than 1G, because a gas giant is going to mass many times what a terrestrial world does. If you want a sort of "gas dwarf," I'd interpret the result of a dwarf or terrestrial planet that way rather than use the gas giant result.
These are each made with 3 1d6 rolls: We have one rocky core with medium gravity and a dense hydrogen atmosphere. I think that having a dense hydrogen atmosphere might be worth a discount on how long it takes to refuel with fuel scoops, so we should consider that in the final writeup. We also get a liquid core, high gravity, made of liquid water. Well, that's quite a thing! The book notes these can support life, so let's be sure and give it at least unintelligent life later.
Now for the Dwarf Planet. These are also made with 3 1d6 rolls for type, gravity, and atmosphere. This is a Glass World, where volcanic activity has turned most of the surface into spires and canyons of razor-sharp obsidian. It has low gravity and a CO2 atmosphere. Not a fun place!
Our one Belt gets only two die rolls: one for type, one to see if there's anything habitable in it. We get Ice Belt, so it's mostly made of frozen liquids and gases, and...it contains a second deep space station! So that's two in this system.
Now, let's develop the two Deep Space Stations. These just get 1d6 to determine a type, so we'll flesh them out a lot more later. One is a refueling station, and one is a military base. I'm going to say the refueling station is the one inside the ice belts. We can imagine that at one time it had tenders that collected hydrogen or water ice, which it rendered into fuel. I haven't decided if it's active yet, though.
Step 2: Add Moons.
H&H puts LOTS of stuff on moons. We have two terrestrial worlds, one dwarf planet, and two gas giants that all might get moons. You roll for the number and also to see if they are "interesting." Interesting usually means they're a planetoid in their own right, and are generated as such.
Our Gaian world gets five moons, but none of them are interesting. The Forest world gets an interesting result, and has a single moon. It's moon is rolled as a dwarf planet, and is...a prison planet! Neat! The exterior is rolled as a stony world, but the interior is rolled as a Gaian world. It has low gravity, thin hydrogen on the surface, and a nitrogen atmosphere on the interior.
The dwarf planet from earlier, the glass world, has two moons. However, Dwarf planets have a relatively small chance of their moons being interesting, and this one is not.
Now, on to the gas giants! These are heavy on moons, as each one receives 3d20. 1d6-1, by the rules, are interesting. That's not how I do things, though. I check for each body to see if it has what I call a "point of interest," and if that comes up positive for a gas giant then it goes on the moons. Otherwise, the star system just becomes unmanageable. In any event, the dense hydrogen world has 20 moons, and the water world has 19.
Step 3: Points of Interest
Now I check to see which orbital bodies I add things to. I have drastically simplified things from the system in H&H, because I don't like fucking with that many modifiers for something I'm going to have to roll a bunch of times. So what I do is this: I roll 1d20 for everything there. If I get 15+, then it was inhabited at some point in the past. I don't need to do this for space stations or artificial worlds, because we already know they were inhabited. Then, for each of those, I roll 1d20 and look for 15+ results again. If I get a hit on those, it means the place is still inhabited by something the PCs might want to talk to. Anyplace with loot is at least going to get hazards and automated defenses.
So, check for prior inhabitation. Look for 15+ on 1d20.
Gaia World: 17
Forest World: 8
Dwarf Planet: 15
Rocky Core Gas Giant: 7
Liquid Water Gas Giant: 17
Well, shit. This place was pretty heavily inhabited at some point. I guess the system is really old, so it's had time. Now let's see which of these places might still be inhabited! Now we add the deep space stations back in, and of course we know that the forest world's Moon Prison was inhabited at one time, as well, even if the forest world wasn't. And, of course, the gas giant has multiple moons we need to check for! Rolling 1d6-1, we get five moons of interest for the gas giant. At this point you have a pretty good idea of how I generate a planet, and the moons work the same way. So, I'll skip over that process and just give you a summary. None of them turn out to be inhabited, except we know the science world would have been. So we check for inhabitation now, and it is currently inhabited. Interesting!
1. Gaia World: 14
2. Glass World: 2
3. Liquid Water Gas Giant:
- Moon A: Terrestrial Forest World, High Gravity, Oxygen. Never Inhabited.
- Moon B: Terrestrial Hell World (volcanic activity, temperature and atmosphere inhospitable to human life), medium gravity, sulphurous atmosphere. Never Inhabited.
- Moon C: Terrestrial Forest World, Low Gravity, Nitrogen. Never Inhabited.
- Moon D: Dwarf Stony World, Low Gravity, No Atmosphere. Never Inhabited.
- Moon E: Dwarf Science World (Covered in massive scientific installations from a prior age!), low-G, Oxygen atmosphere. Currently Inhabited.
4. Refueling Station:19
5. Military Station: 1
6. Moon Prison: 17
Now we know that the Gaia World, the Glass World, and the Military Station are basically just ruins, maybe with automated defenses or hazards. The Refueling Station and the Moon Prison, though, are still inhabited and active! Fortunately, H&H has given us a way to determine the type of ruin on a world.
We need to roll for three of them, because we already know the military base is the ruins of a military base.
Gaia World Ruins: Cities
Glass World Ruins: Monument
Step 4: Arranging Everything.
Now we put stuff in its place. This star is cold, so anything inhabited needs to be close to the star or have some other way of staying warm. If you want to refresh yourself, look down at the bottom of this post for the Final Results. This is also where I start to sketch the story into place.
This is what I'm thinking right now:
The Refueling Station is still active. I don't normally place cosmopolitan locations where aliens meet up, but this might be a good time to have an actual example of that. So, make a note to place alien civs within a couple jumps of this place, with this system acting as a refueling stop for traders, criminals, pirates, et cetera. That means this refueling station is going to have to be pretty well-defended, but I'm okay with that. It can have a market and so forth, too. That'll be fun. So, I'm going to put it on the outer rim of the system, so people can stop by and gas up without going deeper in. That's going to be important.
Next I place the glass world with the monument because it's effectively probably just flavor, and the boring gas giant. Maybe there are some miners who are mining the moons of that gas giant, but nothing big or interesting unless the PCs find a specific plot hook.
Next in, I place the military starbase. I know this is uninhabited, but I also have a pretty good idea right now of what I want to do with it. I think it was placed here to protect the Science World that is on that moon, and it is therefore in the liquid core gas giant's L2 Lagrange Point. It has heavy automated defenses, and will attack anyone trying to pass closer to the store than its orbit. I think maybe it has a pack of automated fighter bays, maybe even a few frigates, and the capacity to self-repair and make more. Trying to pass by it is going to kick the hornet's next, and nobody still alive knows the access codes to get past it.
The gas giant with the science world moon goes next in. I know that whatever is down there is going to be very dangerous, and very valuable. Maybe an unbraked AI went apeshit and built all kinds of weird miracle tech before disappearing. Maybe a bio-plague got unleashed and turned the native life into biomechanical horrors, but there's tons of valuable research data. We'll find out using Dead Names.
Next in I place the gaian world with ruined cities. Could be a lot of treasure here, and it hasn't been picked over, for the most part, due to the automated military base.
Last in, I place the forest world with the Moon Prison. It's getting the most sunlight, such as it is.
In my next post, we'll start filling out these results into more like what you would want ready before the session when the players drilled in.
Initial Results: Betelgeuse Q
White Dwarf Star: Collapsed dwarf stars that have cast off their outer layers as a surrounding planetary nebula, leaving only the very small, dim ball of cooling plasma at their center. Worlds around them are often rather cold, and even in daylight the stars still shine around it and the sky is very dark.
Orbital I: Forest World with Prison Planet Moon. There are still prisoners and guards in there.
Orbital II: Gaian World with Ruined Cities. No intelligent life.
Orbital III: Liquid Core Gas Giant with Lots of Moons. One of them is full of abandoned and highly dangerous scientific facilities!
Orbital IV: Military Deep Space Station. Uninhabited, sends out automated attack ships if anyone tries to enter the inner system without authorization codes, which nobody knows.
Orbital V: Rocky Core Gas Giant. Basically boring.
Orbital VI: Glass World with Monuments. No adventure hook yet.
Orbital VII: Ice Belt with Refueling Station. The refueling station is a trade depot and haven for unsavory types.