Tag Archives: Worlds

The Unwashed Masses (High Population Worlds, Part 2)

Now that I’ve brought those mega-high-population worlds a little bit in line with the rest, let’s take a look at each of them in order to figure out what conditions might be like. For this post I will omit worlds with less than about 15 billion people.

I won’t post detailed analysis for all worlds in the sector, but this should serve as a good example of the way I work, and of how you can turn the simplistic UWP codes into actual places.

(As a note, yellow fields are how I mark data I’ve changed from the original dice rolls in some way.)

(5)Temperate 1429 AA8ABB9-G Hi Ht Wa HI5 (5)Temperate

The most populated world in Colonial Space is an interesting one. It is a large (A = 16,000 km) waterworld with a dense (1.5-2.49) atmosphere. It also has the highest tech level of any system (16), and it absolutely needs it.

What fresh, natural food is being produced is entirely aquatic. Most food is produced in vats and by synthesizers. The human population lives under water, on the water, and in floating cities and there’s probably a sizable off-world presence that gets counted in the total (a billion or two on the moon).

I say “human” because the world is actually quite hostile to human habitation. The gravity is too high, the air unpleasant. Yes, they have the technology to compensate, but I will assume that there is also a sentient aquatic species present. Since you can’t really develop technology underwater, they’ve either been uplifted by the colonists, or are being suppressed and exploited. Perhaps both.

The world is governed by a king and severely restricts contact and trade with off-worlders. The government is keenly aware of their technological edge over the other worlds and seeks to maintain it.

(3)Temperate 2614 BAA5AD9-A Fl Hi HI3 (3)Temperate

Another huge world, this one must be even less pleasant to live on. On top of its high gravity, it has an Exotic atmosphere and half the surface is covered in some sort of non-water. I wonder why anybody would want to live on such a planet, and it’s quite amazing that they managed to grow to 45 billion! I don’t want to assume non-humans, that’s a cop-out.

The planet’s government may give us a hint: code D is a “religious dictatorship”, which the Mongoose Traveller rules book says could be a “cult, trasncendent philosophy, psionic group mind”. None of those are very pleasant, and the implications are clear: The world was originally settled by religious outcasts, and they have some sort of inverse China syndrome. That is, instead of banning people from having children they strongly encourage or even force people to have a large number of children.

Why would they do this? I actually rolled on the Cultural Difference table and got a result of 55 – “Unusual Customs: Lifecycle”. Thanks, dice, I guess I was ahead of you.

Let’s leave the exact motivation up for later, but a large population is a large power base. These guys are certainly not up to anything good.

Last but not least I am going to go out on a limb here and assume that the fluid oceans are hydrocarbons, which serve as basic ingredients for the local synthifoods.

(8)Temperate 2917 B888AA9-9 Ga Hi HI8 68.400.000.000 (8)Temperate

Compared to our first two worlds, this one is almost boring. Yes, massive population, but also quite close to Earth: Size 8, about 80% water, just a bit of a denser atmosphere. It’s still classified as a Garden world and the only downside is the fairly low technology. It’s still high enough that they use carniculture vats, hydroponics, and maybe even imported food synthesizers, but the quality of the food will be a lot worse than on that tech level 16 water world.

With the environment fairly normal, and a Charismatic dictatorship (probably still revolutionary leaders in place from the war), this planet may seem like a fairly pleasant one. However, the massive population and the high law level do mean that the citizens’ daily lives are controlled to a great extent. Unlike the religious planet, this one probably does have strict family planning laws in place. Think fertility boards similar to what Larry Niven’s flatlanders have to deal with.

(3)Temperate 2611 A400A96-D Hi Ht In Na Va HI3 (3)Temperate

Ah, something completely different – a small vacuum world. Small as in Mars-sized, and without oceans this still means about the same land surface as Earth. To accommodate 63 billion people, this world is riddled with caves. The high tech level easily supports all these people, and the surprisingly low law level means that this world is probably the most pleasant to be a citizen on of all the high population worlds we’ve looked at so far.

The planet is probably an economic powerhouse – Industrialized trade code – supported by vacuum industries which in turn are fueled by mining. I wouldn’t be surprised to find that there are several dense asteroid belts, ringed gas giants, and many moons in this system that are all used to provide ore for the main world.

(8)Temperate 1418 C785A96-8 Ga Hi HI8 21.700.000.000 (8)Temperate

Next up, another overpopulated Garden world. With a size close to Earth’s, a dense atmosphere and extensive oceans it’s actually as close to the dystopic visions of an overcrowded Earth as we’ve got so far. The tech level is only 8 – about what we have on Earth today, maybe a little bit higher – which means 21.7 billion people is about the maximum the society can support, especially considering the C class starport implies a limited amount of interstellar space travel and the tech level is not high enough for a lot of “domestic” interplanetary travel.

Government code “A” is a charismatic dictator again, but I think this world – due to its location, if nothing else – was a supporter of Empire. So the local government is essentially unchanged under the Republic, and the locals support their leader because they realize that tight government control is necessary to cope with the large population. This is supported by the relatively low law code – much as on the previous vacuum world, the government is as hands-off as it can be.

If we’d ever want to set any sort of “cyberpunk” sort of adventure in the Contact Light setting, this world is a good candidate for it.

(7)Temperate 2135 B784A89-A Ga Hi HI7 (7)Temperate

This is another overpopulated garden world. The higher tech level supports more people than on the previous world. The government is a civil service bureaucracy, the rules book names communism or technocracy as examples. With the higher law level, this one might be a good candidate for a communist state and in a setting that derives inspiration from 1950s golden age science fiction, communist states make for great antagonists.

Beyond that, the UWP is fairly boring in my opinion.

(5)Temperate 1113 A8A5A89-D Fl Hi Ht HI5 30.500.000.000 (5)Temperate

Didn’t we already do this world? It’s very similar to #2614, except for the government type and for being smaller. A lot will depend on why people settled this world, but we can’t deduct that from the UWP. Alien ruins…

(4)Hot 1935 B743A88-9 Hi In Po HI4 15.700.000.000 (4)Hot

The first thing I notice about this world is the Hot climate; interestingly it’s still got oceans! The atmosphere is thin and tainted, so this world is certainly no paradise. It is industrialized, but poor – the reasons for this are the low tech level and its location in subsector O, outside the Empire (and now Republic). Perhaps the civil war caused it to lose what markets it had, or perhaps the Empire was supporting it and that support now vanished.

On the other hand we’re now looking at a world with “only” 15 billion people. Merely twice what we have on Earth today. And with the amount of dry land this planet has there is a lot of room for these people to spread around. It’s got crowded cities, for sure, but it doesn’t have the massive population problems of some of the other planets.

0.7atmospheres, the upper limit for this atmospheric code, is about equal to a height of 3000m on Earth. A quick check shows that this is below the tree line in some regions, so it’s entirely possible that this planet actually has quite a bit of vegetation.

(3)Temperate 0305 B410AD9-B Hi In Na HI3 (3)Temperate

Another Mars-sized world, and with its trace atmosphere it is very much like Mars indeed. The most interesting thing about this world is its location: It is situated in subsector A, which is very much on the edge of a major rift. It’s also a religious dictatorship.

Why did all these people come here? The UWP won’t give us anything. With law code 8, I think that this world serves as a base of operations to explore the spaces beyond, but the powers that be permit no contact between travelers and the locals (change law level to 7). What are they hiding? It’s a mystery for our protagonists to uncover at some point…


The UWP codes give us surprisingly much to work with, considering it’s just a handful of numbers. At the same time, I am very happy I reduced the number of systems in the sector. The more worlds we have, the higher the chances for similar results.

It does make a lot of sense to use the additional rules Mongoose added – such as various power groups and the cultural difference table – and I will do that for all systems when I work out detailed profiles for them.

Finally, we should never be afraid to override the dice. The random results are a guide, not the law. But this should go without saying, right?

People, People Everywhere (High Population Worlds, Part 1)

One thing you will remember from when we looked at the dice results for this sector was the insanely high total population – 2663 billion people – for what is supposed to be frontier-ish.

This is really due to four population code B worlds – that is, 100 billion or more inhabitants. I’ve already downgraded one of them. In addition, the sector contains 8 worlds inhabited by between 10 and 100 billion people:

(5)Temperate 1429 AA8ABB9-G Hi Ht Wa     HI5 834.000.000.000 (5)Temperate
(8)Temperate 0516 A763BD9-C Hi Ht       HI8 482.000.000.000 (8)Temperate
(3)Temperate 2614 BAA5BD9-7 Fl Hi       HI3 (3)Temperate
(8)Temperate 2917 B888AA9-7 Ga Hi       HI8 95.700.000.000 (8)Temperate
(3)Temperate 2611 A400A96-D Hi Ht In Na Va HI3 (3)Temperate
(8)Temperate 1418 C785A96-8 Ga Hi       HI8 61.700.000.000 (8)Temperate
(7)Temperate 2135 B784A89-7 Ga Hi       HI7 (7)Temperate
(5)Temperate 1113 A8A5A89-D Fl Hi Ht     HI5 30.500.000.000 (5)Temperate
(4)Hot 1935 B743A88-9 Hi In Po     HI4 15.700.000.000 (4)Hot
(3)Temperate 0305 B410AD9-B Hi In Na     HI3 (3)Temperate
Xoth 2219 A576A85-A Ga Hi In     HI7 (7)Temperate

Is this even possible?

From a pure math standpoint, absolutely. Earth’s population has increased dramatically over the past few centuries, as better agriculture and medicine reduced mortality – especially child mortality. When I was a kid, the world’s population hit 5 billion people. I remember the TV gala; for some weird reason people actually celebrated it. 2011, it was at 7 billion. Call it 25 years for 50% growth. Simply continue to feed all these people and you’ll have run-away, exponential growth.

Earth's Population over time, in Billion
Earth’s Population over time, in Billion

Of course, things aren’t as simple as that. First off, the Earth is a closed system and at some point – we are not sure where it would be – there simply won’t be enough food, energy and water. Population would hit a wall and things would turn ugly.

In reality, even if there was no limit to food, energy and water (say because of interstellar imports)  it won’t work out that way.

People adapt to their environment – we’re really good at that. Better health, more wealth, and especially better education also limit fertility. Women simply give birth to fewer children. In the 1950s, it was 5 kids per woman. In the early 2000s, it was half that. The UN expect it to eventually drop to just above 2.05. In other words, a balance will set in, and the best guesses place this at ~9 billion people.

A regular Sunday shopping in Chennai. A good example of the sea of humanity. cc-by-sa, McKay Savage
A regular Sunday shopping in Chennai. A good example of the sea of humanity. cc-by-sa, McKay Savage

In other words, a super-densely populated world isn’t going to happen in any natural way. Population growth is a byproduct of technological progress. If that progress stops, or even reverses, the population becomes unsustainable and will either crash or find an equilibrium. If technological progress continues unabated, then attitudes will change with it and population will find an equilibrium eventually as well, just at a higher level. To put it bluntly, people simply have better things to do with their lives than to raise kids continuously.

Genre Considerations

I am obviously not worried as much about building a realistic population model as I am about creating a setting that fits its genre and is internally consistent and, well, hopefully interesting.

Massively populated worlds are definitely in-genre. Asimov’s Trantor is of course the grand-daddy of them all, and had anything between 40-500 billion inhabitants. Coruscant has a trillion inhabitants. Then there are the many city-worlds of the Warhammer 40k empire (and probably others). Massive, galactic-scale societies support these worlds and absorb their effect on the economy.

In Niven’s “Known Space”, Earth has a population of 18 billion and is described as a crowded hell. Heinlein assumes 11 billion in “The Moon is a Harsh Mistress” and it’s not exactly doing us any good. (Of course in “Starman Jones”, Heinlein assumes that 4 billion people are a lot). In both cases, space travel is fairly limited for various reasons – all those Terrans can’t just mass-emigrate, which limits the effect on other worlds.

The World-Builder’s Solution

My gut reaction was to simply downgrade these worlds – as I did with #2021. However, I reminded myself of the reasons for using a random generator in the first place: It is supposed to spur our imagination, right?

Here’s a map of where those >1 billion people planets are:


The 1.2 in Subsector K is our world #2021, which originally had 786 billion people. Okay, so the absolute numbers are quite too high. But do you notice what I am seeing?

Subsector H, birthplace of the rebellion, has two super-high population planets. Lots of cheap manpower for the war. And that subsectors H-J axis I mentioned? Another super-high population world in subsector J – and the world with the highest tech level in the entire sector! Now, the 834 billion (and 482 billion) are just ridiculously high numbers, but if we fix it like so:


We’ve effectively preserved the random generator results, improved them significantly, and used them to explain the campaign’s political situation.

This brings the population of the sector down to 508 billion people – a fifth of what it was initially.

Next up, we’ll take a look at these planets’ individual UWPs to figure out just how these people might be living.

Quo Vadis, 256?

So. We have a home. Sector 256. This means the work is just beginning – now I need to lay out local space.


The map of local space should be centered on the Imperial Core. That is, by producing this map we imply that “this is it”, similar to how a Terran national map will show, well, the subject of the map plus perhaps parts of some neighbors. Subsectors F and G as well as J and K should thus be the main focus. K is obviously quite sparse – a backwoods area people don’t go to, perhaps comparable to a stretch of desert.

H on the other hand has many worlds that must be quite important – look at all of these A and B class ports and the travel connections between them!

In theory, this could be a neighboring nation but the ideas I have do not allow for a secondary powerful nation. So it’s part of the Empire, and this means I’ll have to expand the map to the “east” a little bit eventually, just to give our protagonists some room to explore.


The Imperial capital world, Mithra, and the original colony worlds the colonists settled on should be close to the center of that region. They do not “have” to be important anymore – just consider the difference between Rome two thousand years ago and now – but they should probably be relatively heavily populated. They should also be fairly close to each other.

Looking at the map, I immediately notice a bunch of temperate worlds which are marked as fairly habitable. (I also notice that habitability index 9 didn’t get shaded, but no matter). These are 1917, 2017, 2118, 2119, 2021, and 2219:

(8)Temperate 1917 X863445-0 Lt NI HI8 25500
(9)Temperate 2017 B8658B9-A Ga Ri HI9 833000000
(7)Temperate 2021 A663BB8-C Hi Ht HI7 786000000000
(8)Temperate 2118 D864951-8 Ga Hi HI8 5770000000
(8)Temperate 2119 C875657-8 Ag Ga NI HI8 4610000
(7)Temperate 2219 A576A85-A Ga Hi In HI7 12200000000

Interesting. #1917 works well for Mithra, just increase the population a little: X863845-0, Pop 156000000. Makes them “Rich” by Traveller definitions and I appreciate the irony. But we’ll get back to that later.

The other three original colonies were Sassandra, Ascalon and Xoth. Let’s use the three garden worlds, #2017, #2118 and #2219, for them. Either the colonists picked worlds most suitable for them, or ones they could easily terraform.

As for #2021, I’m reducing the population code to 9, with 1.19 billion inhabitants.

The Republic

The Republic was founded on Avalon. But where is that? With Mithra in “G”, our logical choices are “H” and “J”. J is probably the better choice – More isolated – but without wanting to foreshadow anything, I really want to place it in H. Let’s assume all those interconnected worlds indicate a tightly-knit community in this province, perhaps they were never too happy about being annexed by Empire in the first place. And Willem II was just the sort of Emperor who would ignore serious problems staring him into the face.

Consulting the map again, I find this:

(2)Hot 2715 A6309C7-D De Hi Ht Na Po HI2 1580000000

A small-ish desert world with high tech, good infrastructure, a very thin atmosphere and a class C government which the Traveller rules book says could be a revolutionary council. Could it be any better?

I can totally imagine these poor bastards, working in the mines under adverse conditions, their living quarters packed due to the high population. Everybody’s poor, and ideas of a Better Future begin to spread.

With the locations of Mithra and Avalon fixed, I’m thinking that the Republic first captured worlds in J, before circling back and attacking the Imperial core worlds from multiple sides. This probably also means that the J-H axis, with travel through the empty space of K, is the main area of Republic control. G is an occupied mess, and F ends up as a region on the sidelines – the Contact Light equivalent of the Regina subsector.

This is what I love about rng’s – they can be so inspirational!


Welcome to Sector 256

It’s been a while since I worked on world generation. Needless to say, the layout of composition of “Imperial Space” is one of the big fundamentals that needs to be settled before I can work on the details of the setting.

I did consider reworking the random generator into generating entire solar systems (Evil Dr Ganymede has posted a great revision of the 2300AD system generation rules that seems about perfect for the purpose) and perhaps into a less grid-based 2D map, or even a pseudo-3D map.

In the end, I think I should not do either of these. For a space opera setting, a realistic map isn’t necessary – in fact, it’s probably a distraction. Most people can’t visualize 3D space very well.

As for Dr Ganymede’s system – it would create a lot of nice detail but in the end I also want to make some progress. If whatever audience this thing gets prefers, I can always retcon. 🙂

To cut to the chase, I played around with a few random seeds, and 256 looks great. Here is the map:


The green circles indicate “habitability”, the darker the better. The lines are “travel routes”, basically they connect all A/B class starports that lie within a certain distance of each other.

What I like about this sector is its structure. Subsectors F, G and H are probably the “core” of the (former) Empire. I think that J might make a good place for either the Imperial capital – adding physical distance to the social detachment that led to the civil war – or the rebel capital – explaining why the Empire didn’t see it as a bigger threat.

Subsectors M and N, as well as subsectors O and P make for one nice “fringe cluster” each. There’s a small group with two very habitable worlds in subsector A – a nice “outpost” area – and a number of colonized worlds in subsector B, which might prove interesting – since none of them is a nice place to live there must be something fairly important there to warrant settlement.


The sector contains 262 worlds with a total population of 2,663,284,385,714. That’s a lot of people and I’ll definitely have to reduce it – there are a number of population B systems.

Tech level distrubtion:


World classes:


Starport classes:


I think this is going to be a very nice sector. Do let me know what you think of the layout!

Next step: Clean up the map, and turn it from a generic sector into our colonial space.

Tech Levels Revisited

Tech Level – assigning a numeric value to a civilization’s technological development – is a powerful idea and having worlds with varying tech levels – often in stark contrast to each other despite physical proximity – is one of the central aspects of the “look and feel” of Traveller. The idea, of course, was a staple of the science fiction genre at the time. Dumarest comes to mind, and Space Viking – but also Foundation.

Other games have used the same concept. GURPS and TORG are two examples I am familiar with, but pretty much every science fiction game has done something similar. None of them are compatible beyond the fact that they use Earth’s development as a model up until the present.

I decided early on – actually before the setting I am working on saw the light of day – that I wanted to use a Tech Level system, and I also decided that I should stay as compatible to Traveller as possible.

A word of warning: This is a long post…

Continue reading “Tech Levels Revisited” »

Size Matters, and Subsector Trial Run 2

The conclusion of the first trial run was that worlds were too big, the change I made was too drastic. So I sat down and did a few more 10k runs. This is a graph of the relevant world types – I consider something like “rich” to be too poorly defined to begin with.

Note that I added “Se” (Super-Earth, size 10+) and “Sm” (Small, size 2-) for this exercise.


I hope it’s not too small to read. Anyway, the graph shows 3d6-3, 3d6-4 and 3d6-5 compared to 2d6-2 when rolling for world size.

Obviously Super-Earths dramatically decrease and small worlds increase during that sequence. Fluid Ocean worlds are also directly tied to large worlds, and Vacuum worlds to small worlds.

3d6-5 would result in more asteroids than 2d6-2. Again, a no-brainer, but since I wanted to reduce smaller worlds not increase them, this seems like a poor fit solely on this criteria.

3d6-4 seems like a good compromise choice for my purpose based on this graph, so I’ll use that.

Tech Level

I haven’t really been able to make TL behave nicer, and I didn’t want to add a lot of filters. I can still do that in the future, but I have another plan.

Trial Run 2 Subsector

TR2 svg-map.pl

Many garden worlds in this one. I like how there again seems to be a cluster – marked by red communications links – of “developed” worlds contrasting with the “frontier” of the rest of the sector.

World Data:

Cold        0101 C941775-8 Po
Hot         0109 C787545-5 Ag Ga Lt NI
Temperate   0110 EA75652-6 Ag Ga NI
Special     0202 XAD5423-2 Fl Lt NI
Cold        0205 X410000-0 Ba
Temperate   0210 X410000-0 Ba
Temperate   0304 X967543-1 Ag Ga Lt NI
Cold        0308 B754431-6 Ga NI
Cold        0403 ECA6373-6 Fl Lo
Temperate   0405 X893224-3 Lo Lt
Special     0410 XBE4315-0 Fl Lo Lt
Hot         0501 EB86000-0 Ba Ga
Temperate   0506 C553442-5 Lt NI Po
Cold        0508 D567523-4 Ag Ga Lt NI
Cold        0510 X4A4465-1 Fl Lt NI
Cold        0601 X510467-4 Lt NI
Roasting    0606 CAC1775-7 Fl
Temperate   0608 B653965-9 Hi Po
Temperate   0703 E986242-4 Ga Lo Lt
Temperate   0705 B8529A9-9 Hi Po
Special     0802 EDD3341-4 Fl Lo Lt
Hot         0803 X9C7340-2 Fl Lo Lt
Temperate   0805 D7489B9-5 Ga Hi In Lt
Temperate   0808 A568BA8-A Ga Hi
Temperate   0809 B684475-B Ga NI

World #808 has a population of B, “hundreds of billions” and  must be the undisputed superpower of this subsector. Tech Level is again generally fairly low, considering I was aiming for a nominal 13 on “core” worlds, but it is a fairly decent mix if one looks at it as a pure Traveller-like premise.

Subsector Trial Run 1

Now that we’ve looked at all characteristics, it’s time to roll up an entire subsector – my first “real” trial run! I’ve modified the subsector map script so that it handles the slightly non-standard UWPs I am producing.

I’ve also generated trade code classifications as per the Mongoose Traveller rules.


This is the data I came up with:

Cold        0103 D3A6330-9 Fl
Temperate   0109 EB9A872-7 Wa
Temperate   0110 C574778-9 Ag
Temperate   0204 X879155-3 Lo Lt
Temperate   0301 C310789-A Na
Cold        0302 E300434-6 NI Va
Hot         0303 X8B4000-0 Ba Fl
Temperate   0307 BAA2778-C Fl Ht
Hot         0309 C6307A9-A De Na Po
Hot         0310 D7A79D8-2 Fl Hi Lt
Hot         0402 X8B5444-3 Fl Lt NI
Hot         0407 ECB6527-3 Fl Lt NI
Cold        0502 E764468-6 NI
Hot         0503 D697357-8
Special     0603 CDEA740-A Fl Wa
Searing     0605 X100000-0 Ba Va
Temperate   0608 XA626B8-2 Lt NI Ri
Cold        0702 E100347-8 Va
Frozen      0704 EBB6231-8 Fl Lo
Temperate   0705 X830116-3 De Lo Lt Po
Special     0706 XCE6131-2 Fl Lo Lt
Searing     0707 X7B4100-1 Fl Lo Lt
Roasting    0708 CA88756-5 Ag Ga Lt Ri
Temperate   0805 E566750-6 Ag Ri
Temperate   0807 D886412-2 Lt NI
Hot         0810 XB86113-0 Lo Lt

Looking at this data, I may have to change my world generation process a little.

  1. I think I definitely did overcompensate on the world size. There are too many big worlds in the mix now, and it’s hard to get asteroid mainworlds at all. In my 10k worlds trial run, a mere 50 main world asteroid systems exist. I wanted to make them more rare, not eliminate them.
  2. TLs are definitely on the low side. Out of the 26 worlds, 14 worlds have a tech level of under 7. Two worlds are not inhabited at all. #307 has a TL of 12; #301, #309, and #603 have a TL of 10.
  3. Too many population 1 worlds, 10-99 people. These are really hard to explain if they have a low tech level. I probably do need to enforce a “minimum tech level based on environment” – Worlds #707 and #706 for example seem silly.
  4. Otherwise population seems Okay-ish. Primitive societies also seem to have very low population numbers (stone age population of Europe, for example, is estimated between 4000 – 30000 individuals) but some of the values generated are a bit odd.

Now that I can easily create large sets of worlds/systems, I can tweak some of the rolls and constants and see what comes out of it.

Things to try:

  • World size: Larger negative DM to world size. Perhaps make it -4 or -5 instead of -3.
  • Tech level: A large positive DM comes from starport class, and a low population world can’t have a high-class starport.  Since population 1 are almost certainly not natives, they ought to have a much higher TL. Current DM is only +1, and at the same they will be penalized for a bad starport class since that is now dependant on population; it may make sense to be radical about it. Ignore star port TL modifier for low population worlds and even add a +7 or so instead. Population 2 is probably the same. Population 3 can easily be a viable stone age civilization.

Overall, though, I think we’re on the right track.

Update: After writing this, I discovered that my world generation script evaluated the Lo and Ga trade codes incorrectly. It’s fixed for the future…

Tech Level

Tech level is determined by 1d6, with tons of modifiers based on all other characteristics of the world. In short, good startports, small world size, unusual or thin atmospheres, very low or very high hydrographic percentages and low and high population extremes give a bonus to TL.

The Mongoose Traveller rules also impose a lower limit on TL based on atmospheric type. If the tech level is any lower, the locals are unable to build or maintain the machinery which enables their survival. Their TL list is a little odd, though.

Test Data

The test run of 10000 worlds gave me this distribution:


The exact numbers at the high end:

197 C
108 D
56 E
35 F
9 G
2 H

The two -H worlds are:

Temperate   40803 A310AC9-H Hi Ht In Na
Special     47003 AADAAA9-H Fl Hi Ht Wa

Both would be interesting worlds to detail.

Anyway, the distribution works for me, since I wanted to keep the Tech Level to 13 (or as low as possible). The TL0 spike may be something to keep an eye out for, and of course we’ll have to see how this looks with actual sectors… Time for another trial run.


Starport code is determined by 2d6-7, adding the population score, under the “hard science” world generation rules, instead of the straight 2d6 roll normally used. The result is then looked up on this short table:


Starport Class

2 or less




















This does mean that class A ports will be very rare under our variant rules, because it takes a world of at least population 6 to even have a chance at a class A port, and then they are rare. A population 9 world – “billions of people” – has a 27.78% chance of an A class star port.


Doing a test run of ten thousand worlds, using my rules variants, I get the following:


Put it in context, this means we’ll have about 16% “core worlds”, 38% “colonies”, and 46% “frontier worlds”. If I go with a subsector star density of expected 22 worlds, this means 2-3 worlds with class A or B. In theory. If it works out that way, I think I may be on the right track – always keeping in mind that I expect to fudge things anyway.

What do those codes mean?

I have been trying to maintain the meaning of the individual world characteristics, but the starport codes will be the first slight departure. Since the explanations in the Mongoose Traveller rules are not part of the SRD, and because they are fairly ill defined anyway, I decided to create my own definitions.

It makes sense to have an in-universe definition anyway.

They’re similar enough that someone who wants to just use my sector data will still be able to do so:



Found on



Major Hub

Major worlds

All services, including major shipyards.


Medium Hub

Major worlds

All services, including shipyards.


Minor Hub

Major colonies

Limited services. Repair facilities only, no shipyards.



Normal colonies

Very limited services; spaceport is fenced in and has basic security perimeter. Fuel available, but no construction and extremely limited repair facilities.


Landing field

Primitive worlds or very minor colonies

Spaceport is nothing more than a marked field, perhaps with some local businesses nearby that serve travelers.



Primitive worlds, recently-established colonies, uninhabited worlds

No spaceport at all.

Starports are rated by the Imperial Space Transportation Authority; rating A is only granted to truly major ports which also serve as traffic control hubs for their surrounding space.


Ah, law levels. Where should I even begin. The basic concept is the same as with the other characteristics of a mainworld. Roll 2d6-7, this time adding the government value to the roll. I think the concept is as old as Traveller, and nobody ever bothered to revisit it – which is just as well, because I again think that this is too varied a topic to just solve with one roll.

For example: The law level table has six categories, but a society doesn’t necessarily restrict different types of item to the same degree. For instance, Germany does restrict weapons (law 8) but has a free press and really no restrictions on software (Information law level 0-3 depending on your view).

Finally, I think that directly basing it off the government value is… problematic. While the government table is ordered roughly in such a way that more “liberal” societies are associated with lower government characteristic numbers, and more repressive ones with higher numbers, I don’t think this necessarily means that they oppress everything in massive ways. And there are strange exceptions; for example a “captive government” is code 6 and those tend to be fairly restrictive.

A better way is perhaps to assign each government type a specific DM, and then roll for each column separately. Then use the highest value in the UWP. Of course this results in a lot of extra data and that will dilute the simplicity of the universal world profile.

What I Will Do

I will roll for law levels normally, but I will not take the value as a rule. Instead, it will be a guideline, indicating whether a planet is more liberal or more restrictive than the norm. Then, once I have worked out the general law level of the interstellar polity each world belongs to, I will rework the values to make sense.