Tag Archives: setting

World Stats: Native or Colony

In the “Generic: Government Types” post, populations are assumed to be native and population size and tech both start low and increase more or less in tandem (as tech level generally limits maximum population size).

However in a Syfy setting a lot of the systems are likely to be colonies of some kind – particularly resource extraction or refueling stops between more important systems – and the normal rules relating to govt. type don’t necessarily apply to such colonies.

So the first step in deciding govt. type is deciding whether the world type is:

native + colony



Traveller only has a few aliens in 3I space that are unconnected to the Ancients so “native” here will generally mean a colony from a previous space empires that has become native over thousands of years and critically could have had at least one tech and / or population crash in that time so their current state could be anything from stone age to space age and any possible govt type.

A planet with a native population i.e. one that has potentially had thousands of years to grow ought to have a large population (9+) unless it has been limited by technology level or the harshness of the planet.

Taking earth as an example then Traveller population code 9 (billions) became possible at a tech level of around 8 but a population code 8 (hundreds of millions) had been feasible over a broad range of tech levels.

So population 9+ = native

  • pop 9+ and mid/high tech would be the standard successful planet
  • pop 9+ and low tech might  require an exotic explanation for how such a large population can be sustained at low tech levels


pop 9+ = definite native
pop 6-8 = possibly native



If very large populations are generally assumed to be “native” then very low populations (5-) can be generally assumed to be a colony.

Colonies can be associated with a dominant star faring species / civilization or be contrary to it. A “contra colony” will be made up of people trying to get away from the dominant civilization.

High tech colonies will be more likely to be 3I related and low tech colonies more likely to be contras.

The kind of 3I connected colonies referenced here would be: navy or scout bases, some element of the non-executive parts of 3I like prisons, nature reserves, research facilities etc and commercial colonies (usually resource extraction of some kind) whether noble, corporate or free company (Belters).

Contra colonies include cults of various kinds, historical fanatics, ideological fanatics, simple living clans, freedom orientated groups and the kind of Belters too anti-social even for Free Companies.

low pop (5-) definite colony
mid pop (6-8) possible colony

contra colony
  • more likely to be low/mid tech
  • more likely to be off the main trade routes
3I colony
  • more likely to be high tech
  • more likely connected to the trade routes


Pop 6-8, Native or Colony?

Populations of 6-8 can be native or colony. The general rule of thumb being they are either colonies that have done unusually well or natives who have done unusually badly.

Successful Colony (mostly pop 6)

Requires explanation why the population is higher than most colonies.

  • prime colony – a colony being green housed by the 3I e.g. building a fortress system on the border or opening up a trade route. These systems will be primed by ship loads of colonists from the core under 3I’s Colonial Service.
  • resource extraction colony where the resource is particularly valuable or labor intensive
  • contra colony that got lucky
Stunted Native (mostly pop 7-8)

Require an explanation why the population never reached higher levels if they’d been around thousands of years.

  • harsh planet – population is limited by something in the world stats: size, poor atmosphere, water world, desert etc
  • okay planet with hidden flaw – population is limited by something *not* in the world stats: strange orbit, tide-locked, lack of critical element like wood or metal
  • okay planet with cultural restriction – religion or ideology restricts tech
  • population recovering from a catastrophe

tide-locked is particularly useful as planets with nothing obviously wrong with them can be set to that.

One exception to the idea of stunted native is the “Elf” form of native society, prime planets that currently have mid pop & high tech, where the population had reached high pop & high tech in the past and then consciously decided to let the population decline until it reached an ideal balance. These societies are (or were) focused on medical high tech and as a result have high longevity and low reproduction.

In my 3rd Imperium a necessary condition for a utopian society is tech > pop so “Elf” societies can be utopian (as high tech > mid pop) but if boredom and decadence set in they can also turn dystopian e.g. fantasy genre “Dark Elves”.


Native + Colony

In the context of govt. types this is where a population that meets the conditions for “native” has been brought into the empire of one of the dominant star faring polities so the colony part is the military and executive colony of the empire on that planet.

This can mean either that the planet has a native govt. type modified by the presence of the Imperial colony or that the 3I colony is the govt. type.

The main deciding factor whether a native system becomes native + colony will be the trade network map.

Most of the Alpha systems (high pop + high tech) within an empire will be native + colony – a native base population and a 3I military / admin population plus some of the more important systems along the main jump routes between the Alpha systems.

(As the Alpha systems would generally have run their own pocket empire before the 3I showed up they may have done the same thing to nearby worlds in their hinterland before the 3I showed up.)

Outside the 3I there might be systems with native + multiple competing colonies, for example a planet with a large native population and both a 3I and Zhodani colony on the same world.

(nb Many systems with a native society could also have colonies which aren’t relevant to government type e.g. a large mid tech (not space faring) planet might also have a 3I mining company operating on an outer moon but that won’t effect govt. type.)



  • Pop 5- = colony (standard or contra)
  • Pop 6-8 = successful colony or stunted native (or Elf native)
  • Pop 9+ native (or native + colony)


Taking the points made in Generic: Government Types what might a fantasy version of the Traveller system look like?

In a fantasy version you’d roll per region rather than per world so say population = 2D6 divided by 2 and rounded down giving a range of 1 to 6

(which in Traveller is the number of 0s in the total populations so population level 1 = 10s of people, level 2 = 100s of people, level 3 = 1000s of people etc.

with DMs of say

  • coastal fertile river valley DM+3
  • interior fertile river valley DM+1
  • temperate hills, woods DM-1
  • plains, steppe, forests, swamps, desert DM-3
  • mountains DM-4

then the government table might be 2D6-6 plus population level

  • 0 none
  • 1 clans or corporations (forestry, mining)
  • 2 small tribes (mixed monarchy)
  • 3 large tribes (mixed monarchy)
  • 4 feudal – monarchy/conquered tribe
  • 5 nation / city state – monarchy
  • 6 nation / city state – corrupted monarchy
  • 7 nation / city state – oligarchy
  • 8 nation / city state – corrupted oligarchy – aristocratic or mercantile or religious
  • 9 nation / city state – democracy
  • 10 nation / city states – corrupted democracy
  • 11 nation / city states – dictator/usurper
  • 12 nation / city states – bureaucracy

corrupted systems will contain elements of civil war / repression.

Traveller has random government types for star systems.

0 none
1 company corporation
2 particpating democracy
3 self-perpetuating oligarchy
4 representative democracy
5 feudal technocracy
6 captive government
7 balkanization
8 civil service bureaucracy
9 impersonal bureaucracy
A charismatic dictator
B non-charismatic dictator
C charismatic oligarchy
D religious dictatorship

and they are specified by rolling 2D6-7 and adding population which is given by a number averaging around 7. Does it make sense and could it be better?


Thinking About Government

What factors are important?

  1. Interests
  2. Scale
  3. War


The baseline is

  • everyone in a society has interests which gives them a reason to want a say in how the society is run
  • if a minority can place themselves in a position of authority they can put their interests first
  • if such a minority doesn’t treat the interests of the majority equally there is potential for conflict

This seems to me to create the potential for a perpetual engine of conflict and this engine could drive government forms in a cycle.

For example a cycle like (where the non “corrupted” version is assumed to be a state where the rulers look after everyone’s interests and not just their own and the “corrupted” version is the opposite:

  • hereditary monarchy
  • corrupted monarchy
  • oligarchy/aristocracy
  • corrupted oligarchy/aristocracy
  • democracy
  • corrupted democracy
  • dictator (non hereditary monarchy)

and then back to hereditary monarchy again.

(Aristocracy / Oligarchy is an arbitrary distinction I’m making based on level of external conflict – more war = tendency to military aristocracy, more peace = tendency to some kind of oligarchy – religious or mercantile.)

Effectively it’s saying that human nature is in a perpetual battle against political entropy (aka corruption) hence the cycle.


Making decisions with larger numbers of people is harder.

Making decisions over larger distances is harder.

Technology may reverse this over time.


Government tends to be divided into

  • executive
  • arbitrators/judiciary
  • legislature/mass

and a lot of societies contain elements of monarchy, oligarchy and democracy at the same time with the executive tending to monarchical, the arbitrators/judges tending to oligarchy and the legislature/mass tending to democracy

Warfare requires a chain of command so a society permanently at war will tend more towards the monarchical/aristocratic and a peaceful society more towards oligarchy/democracy.

So how do these three factors play out historically?


Historical Sequence

Small Tribal Society

These often follow a similar basic pattern

  • executive monarch
  • oligarchic judiciary (often a priesthood) and/or warrior aristocracy usually based on wealth/equipment
  • democratic assembly of tribal warriors

Those in a permanent state of raid-war will tend more to the monarchy/aristocracy side because defense will be a bigger part of their collective interests. Those more at peace can drift more to the priest/assembly side but small tribes are unlikely to be at peace much unless isolated.

Large Tribal Society

(defined as where a general assembly of all the warriors would be physically too big)

created by a tribe expanding and/or absorbing related small tribes

  • similar to the small version except scale forces government to be divided into sub-regions for practical reasons-
  • each sub-region mirrors the original model except the executive is an earl or count not a monarch
  • the earls collectively make up the warrior assembly of the upper level of government

this is a kind of consensual bottom up feudalism which still retains democratic elements e.g. the pre-Norman Anglo-Saxons.

If a large geographical tribe remains unconquered then the next step is nation state. If it gets conquered then the next step is feudalism.


A lot of people would say this comes second however I would say the feudalism most people think of – because it is the most common – always comes about as a result of conquest.

In this version the conquering group becomes the ruling class and the conquered become serfs. However the ruling elite maintain the tribal pattern within the ruling layer. The warrior assembly becomes the assembly of barons, the judges/arbitrators will be as before and the monarch as before.

If the conquerors eventually merge with the conquered population then this stage was just a detour on the way to nation state.

If the conquerors don’t merge with the conquered then you’d get a caste nation state.

Nation State

With more scale – people and land- you get to the nation state version of the same thing. I’d say the big difference here is as tribes expand and absorb other tribes eventually they start hitting solid geographical barriers like the sea or mountains and these barriers reduce conflict and as conflict reduces the pendulum swings from warlike monarchy/aristocracy to more peaceful oligarchy/democracy. This takes time though and as not all groups reach this state at the same time this will also be the age of large empires. Scale leads to bureaucracy.

Caste Nation State

Long term feudalism where the conquerors never fully merge with the conquered but manage to maintain long-term stability.

Tech Divergence

Before nukes the transnational options that might occur after this are maybe impersonal bureaucracy for huge nations (like China) or empires.

After nukes…

Nuclear Nation States

Eventually war becomes too dangerous and the nations settle down into civil service bureaucracy.

Transnational Options?

Transnational impersonal bureaucracy – tending to 1984 (probably masked by ideology)

Transnational corporate oligarchy – tending to Blade Runner (probably masked by fake democracy)

Magic Hitech Planetary Democracy (genuine)


so in terms of increasing societal scale and both frequency and potential devastation of war the sequence might go like this

wandering bands


small tribes

large tribes

feudal states

nation states (or caste nation states)

if no nukes then

national civil service bureaucracy or empires


chance of devastation


(enforced peace followed by)

national civil service bureaucracies

transnational options

  • transnational impersonal bureaucracy (tending to 1984)
  • transnational corporate oligarchy (tending to Blade Runner)
  • magic hitech planetary democracy (genuine)

where all the pre-transnational options would likely cycle or oscillate between monarchy – oligarchy – democracy as they became corrupted with a skew toward the monarchy/aristocracy side if constantly at war and a skew to oligarchy/democracy if mostly at peace

religious dictatorships might be most likely to occur in relatively protected large tribes and nation states (like Ancient Egypt)

military dictatorships more likely in relatively wartorn large tribes and nation states (like Rome)


Whatever is rolled can contain anything lower down the list e.g. a genuine hitech planetary democracy might have some regions which still contained small tribes.



My 3rd Imperium: History


Official 3rd Imperium History

The Traveller 3rd Imperium setting has an official history with the players starting in year 1105.

which says the 3I has been running the Spinward Marches for c. 700 years. This is too long for the feel I want.

My Alternate Timeline

In my Traveller universe I’m saying it took the 3I longer to expand, roughly an average of 50 years per sub-sector in any direction so as Vincennes in Deneb is c. 16 sub-sectors away from the core say it took c. 800 years to get to the edge of the Spinward Marches.

800: edge of Spinward Marches

850: Mora

900: Trin’s Veil, Rhylanor and Lunion

950: Glisten, Lanth, parts of Regina and Aramis – Jewell seeks 3I protectorate.

1000: Vilis, Regina – Jewell associate

1050: Five Sisters

In progress: building up Aramis, Vilis, Five Sisters, improving route to Five Sisters, Jewell, diplomacy District 268

So Mora has been part of the 3I for c. 250 years, Glisten c. 150, Vilis c. 100 years, Five Sisters c. 50 years – much more frontiery.

Population Sizes

The systems in Spinward could have been colonized by

  • the Ancients: humans, modified humans or others
  • the Vilani
  • Second Imperium
  • Third Imperium

so large populations aren’t surprising. The Marches are the 3I’s frontier but they are not frontier in the sense of being undeveloped.

Also in between the big empires, alpha systems may have risen and fallen creating their own pocket empires for a time so there cab be ruins everywhere.

Frontier Wars

In the official history there have been a number of Frontier wars with the Zhodani mostly revolving around Jewell

  • two in the 600s
  • one in the 900s
  • two more in 1080 and 1107

In my alternative time line the first three are bumped up and the second two stay the same

  • the first three involved escalating skirmishes in the 950s with the Jewell cluster’s own fleet itself being the largest force
  • well planned major Zhodani attack 1080
  • 5th Frontier war incoming

Player Start

any of

1065: second survey

1082-1084: 4th Frontier War

1085 to 1104: a bit less impending war (but potential for salvage, lost ships, spy stuff etc)

1105: standard start, big war incoming

or even way back 800-900 when the Imperium’s border was still in Deneb.



Warning – this whole post is a spoiler.

Official Version

In the 3rd Imperium setting of Traveller there are a species called the Ancients who did stuff and a boss dude called “Grandfather” more or less detailed here:


Anyway in my quest to include every existing sci fi trope in the Spinward Marches…


My Version

Grandfather and the actual Ancients are D&D mind flayers / Cthulhu Starspawn type creatures – the Droyne are a servitor species.

They developed immortality requiring some kind of vampiric process.

Not nice.

They were big on genetic engineering and mass gladiator battles.

They picked up humans and modified them, sometimes just for fun, sometimes for practical reasons so they could work more easily on a particular world with droyne as slave drivers but they also used them for war-sized gladiator type battles e.g. Waterloo or Kursk sized, including Mecha type battles and battles against giant robots – Vland still has a cultural memory of these. The gladiator humans were generally left unmodified to make the battles even.

The Ancients liked to bet on the outcomes of the battles.

Sometimes Ancients would control the battles directly using psionic powers to give orders to the officers on the ground like a computer game with real blood.

Anyway apart from all that the Ancients built all kinds of high tech wonders – artificial planets, ring worlds etc blah blah.

They also built a robotic fleet with an AI which – you guessed it – went rogue and developed a version of the Prime Directive: that it was wrong for a space-faring species to interfere with a non space faring species. After the Ancients refused to obey the Fleet’s order to desist (and as despite all their psionic powers they couldn’t regain control of their robotic forces) the Fleet attacked and destroyed all the Ancient’s industrial worlds, anything capable of building ships and anything that could become capable of building ships.

Only Grandfather and 420 Ancients survived this destruction most of them on research stations on worlds with little other infrastructure.

Fleet moved out into the universe looking for other breakers of its Prime Directive but not before leaving behind TL18 stealth ships containing hunter killer terminator robots to hunt down the last remaining Ancients.

Grandfather escaped into a pocket universe while the others were hunted down – not all were however, many of them found a way to hide. The terminators, stealth ships and Ancients are still there in the OTU hidden.

Consequences in Game

– hidden TL18 stealth ships in system with unaccounted for Ancients, literally hidden just sitting on a moon somewhere powered down for thousands of years waiting for a scent

– Terminators, some on the stealth ships, some on planets. The ones that got their target designed to self-destruct but those who never found their target just power down and wake up every few centuries to sniff. Invisible in stealth armor one could be sitting on the roof of an Ancients site powered down while Imperial archaeologists work below.

Terminator – botched self-destruct, mangled Terminator somewhere

– Surviving Ancients who hid themselves in various ways to evade the Terminators: cybernetic Dalek form, bio-engineered form, stasis, sealed inside an impregnable tomb etc

– Grandfather, if players find his pocket universe he tells them various lies to get them to check out systems where there may be a surviving Ancients and/or tries to get them to find and destroy Terminators for him. Say c.120 of the surviving 420 Ancients were killed by Terminators and he’s rescued c. 100 over the years and he’s still trying to gather in the remaining 200 or so.

– wandering Ancients – possibly transformed to hide scent from terminators

– misfiring Terminators – an Ancient created an item to act as a decoy which gives off Ancient’s scent, players find it


 Vlandian Games

As mentioned Vland retained a cultural memory of their role in the Ancients gladiatorial games particularly the Vilani gladiators having to fight giant robots. This passed down through festivals and semi-religious symbolism but after the development of grav tech spawned an entertainment involving giant Mechs with teams of players inside controlling them. This is now an interstellar sport with a league in many sub-sectors.


Realistic Star Faring

applied to the Traveller setting.


I forget the exact numbers but IIRC earth has been around c. 5 billion years or so and sentients only about a million years, agriculture only ten thousand years and potentially pre-stellar for only a hundred.

So even with an assumption of one potentially earth like planet/moon per system then if they all formed at different times I think it comes to around one in five thousand systems where the planet has been around long enough for life to have started and long enough for life to reach cavemen.


If the average Traveller sub-sector has say c. 30 systems then a full sector on average has c. 500 systems so that would mean one system had reached an alien version of neanderthals per 10 full sectors.

Sentient aliens with agriculture would be around one per 1000 sectors and pre-stellar aliens one per 100,000 sectors.

The entire Imperium is like 20 sectors.


Those sums are probably very inaccurate but they illustrate the idea that the first species to interstellar is going to find sector after sector of planets that are only partway to being livable and of those that are livable most will only be partway to producing a sentient species.


So if humans were first then I think the logic of it is the first star settlers would expand out exploring in all directions and as the people who do the colonizing will be the sort of people who want to do it then if they produce similar kids the process becomes self perpetuating.

In the Traveller setting most of this early colonizing wouldn’t actually be colonies to live on; it would be building stepping stones for refueling for the next jump but it would be necessary to get tothe next step and the people doing it don’t stop because at the beginning of the process people were selected who were the sort of people who couldn’t stop.

Eventually they’d arrive somewhere that had a real world and pre-sentient alien monkeys. Generally I think taking the top niche in the food chain would prevent any native pre-sentient evolving naturally so that species would be blocked unless quarantined but maybe the humans would uplift them just for the novelty. They’d uplift planets for sure or at least start the process.

So they’d spread everywhere, living in domes a lot of the time while speeding up planetary evolution. In most places their presence stops a native sentient developing but  maybe they uplift some themselves gradually adding Wookies and Ewoks to their ship’s crews along the way and just keep spreading because they can’t stop.


So one option – humans are first and spread like a wave in all directions until after 50,000 sectors or so of colonizing mostly rocks and the occasional monkey world they eventually bump into another star faring sentient species.

Which is a bit like the Ancients in the Traveller setting.


Modified Humans – Crout

In most sci fi the aliens all look like slightly modified humans whereas in Traveller they mostly are modified humans – modified by the Ancients to suit a particular planet – which is good really as creating believable and cool alien cultures is hard.

Crout are descended from the Tcho-Tcho variety of modified human seeded by the Ancients to terra form low oxygen planets.


Small planet, very thin, tainted atmosphere – oxygen vs CO2.

Lots of sea life but barren land apart from microbial mats Crout grow for food.

Crout are short, thin with large chests and large eyes and can breath the atmosphere without problem. They have a blue-ish tint and both their eyes and the whites of their eyes are blue.

World is made up of many densely packed small towns, four houses stacked on top of each other, narrow pedestrian streets – Crout like being close together – agriculture and light industry. Each township is self-governing. Culture is dominated by religion officiated over by a matriarch priestess one for each town. (Amish-like) Very strict about violence.

Crout is mostly self-sufficent and has very little to trade.


Small planet, very thin, tainted atmosphere

A Crout heresy led to division and civil war some time in the past and an eventual exodus of the heretics to the very similar planet of Horosho.

The main difference is the heretics have a heirarchical priesthood with a supreme leader.

The Horosho Crout have developed higher tech including ships.

The Horosho Crout sometimes send missionary ships to Crout often sparking trouble.


Some Crout leave home for a few years in their youth to travel. Crout / Crout often work as and make good stewards. Horosho / Crout have a wider variety of  skills and are less amiable on average.

Being adapted to a very thin atmosphere Crout need to breath through a filter in a standard atmosphere or they get drunk from the oxygen.

Crout who get addicted to this are called “airheads”.




key point: a lot of earth like worlds spent most of their time as

  • barren land, barren sea, CO2 atmos, no ozone, extreme radiation
  • barren land, microbial life bottom of the ocean, CO2 atmos, little ozone, high radiation
  • barren land, ocean life, very thin oxygen, low ozone, medium-high radiation
  • coastal land microbial life, thin oxygen, medium ozone, low-medium radiation
  • land life, ocean life, thin oxygen, high ozone, low radiation

which could be treated as

  • trace
  • very thin, tainted
  • very thin
  • thin, tainted
  • thin


Standard Atmosphere

Atmosphere 6 is the standard atmosphere which humans are adapted for and worlds with this type of atmosphere are denoted as Prime worlds.



Tainted can mean anything from a minor to a major problem. If a planet had a large population then it is generally minor. If a planet has a low population then it is probably major.


OTU Problem

In the CT world gen rules atmosphere type has no effect on population size and the original Spinward data and that data is based on the CT world gen I need a reason why type 6 planets weren’t favored while worlds with bad atmospheres can have billions of people.

IMTU Solution

In early exploration finding Prime worlds was the goal and other worlds were colonized simply as stepping stones.

However as Prime worlds are rare most of the humans in various forms seeking them out ended up spending centuries living in artificial domed habitats on all the worlds in between and people gradually came to see domed living as normal, if not preferable. By TL12+ most people prefer artificial habitats to natural habitats and live in domes even on atmos 6 planets. Only a minority of back to nature types prefer natural living. Hence preference is no longer given to Prime worlds only worlds with a good source of hydrogen and oxygen.

Alternative Solution

Change World Gen so atmosphere has an effect on population, something like:

population roll D6

atmos 0-3 DM-2
atmos 4 DM+2
atmos 5 DM+0
atmos 6 DM+4
atmos 7 DM+2
atmos 8 DM+2
atmos 9 DM+0
atmos 10+ DM-2

hydro 0-2 DM-2
hydro 3-4 DM-1
hydro 6-8 DM+2
hydro 9+ DM-2


Atmosphere Codes

0: vaccuum

1: trace

2: very thin, tainted

3: very thin

4: thin, tainted

5: thin

6: standard

7: standard, tainted

8: dense

9: dense, tainted

A: exotic

B: exotic corrosive

C: exotic insidious

(exotic: thin low, ellipsoid, dense high)



occasional list of exotic atmosphere types

Carbon Dioxide (Earth Archean Age)

warm & cloudy
atmosphere: carbon dioxide
seas: carbonic acid
lots of small continents
volcanic around the continent edges
lots of seas and lakes

rare raw materials around the volcanic rim?

domed and requiring manufactured oxygen and water but abundant sources of components

can be terraformed by adding photosynthetic microbes that will convert carbon dioxide to oxygen


atmosphere: chlorine

seas: hydrochloric acid

chorine based photosynthesis

yellow-green haze


Gravitics Handwavium

The handwavium for how gravitics works IMTU.


Basic Idea

Some kind of power source that creates a field which reacts with gravity. The polarity of the field can be adjusted such that the gravitational force is applied differently.

Earliest/cheapest grav tech can simply reverse the field so gravity provides lift.

First gravs were: large external power source, sea level, external power applied to field generator attached to a chassis, result the chassis rising above the ground and hovering – hover sled.

Over time improved: power source small enough to be carried on the chassis, solid hover ability, separate source of thrust – hover tank.

Over time improved: field generates multiple of G force so can lift rapidly also field can be angled to give thrust and lift – flying tank.

Over time improved: full air/raft functionality.


Secondhand Market

Re-conditioned grav components from scrapyards are jury-rigged into black box components on systems like Glisten for sale on backwater planets. The advanced controllers are generally removed so components only provide lift but they can be bolted onto platforms and switched on and off which is the minimum needed. Grav parts like this are used on hundreds of lotech worlds with the thrust supplied in hundreds of different ways including animals, steam engines, wind etc.

Basic reconditioned grav parts and spare parts for other tech is a very common Free Trader cargo.

A lot of backwater systems have a hybrid kind of gravpunk technology where the cheapest kind of grav tech is combined with local tech capability so John Carter on Mars type planets can exist in the remote parts of the 3rd Imperium where the dreadnought fleets never go.

Trade Network


My Spinward Marches Trade Map


(courtesy of the awesome )

  • dark green routes are the hinterland routes
  • purple are the long distance routes between alpha systems – these also overlay some of the hinterland routes
  • light green routes are subsidized by the Imperium for policy reasons (e.g. building up border systems)
  • yellow circles are alpha systems (and sub-sector capitals if different)


Trade Assumptions

1) Systems represent whole solar systems so from TL9+ onwards worlds can easily be self-sufficient in raw materials.

2) Interstellar shipping costs per ton per parsec are high so

  • it’s only going to be economic to ship low value goods a short distance, say one or two parsecs, and only to systems which might have demand in excess of what the system can produce itself
  • medium value goods are restricted in a similar way, say up to six parsecs
  • high value goods: tech, luxury items, rare materials, unique planetary items etc can be profitably transported long distances but only in large amounts to systems which have a high demand for high value goods i.e. rich, high population planets



Trade in Traveller will mostly revolve around the alpha planets.

(Defined IMTU as class A star port, pop 8+, TL 12+.)

1) The alpha systems have high value tech to trade for what they want.

2) The alpha systems might have a demand for common raw materials because they have already used up the easiest sources in their system so deep mined local copper might be more expensive than copper that is open mined on a nearby system and then shipped – as long as it is nearby.

3) Assuming that an alpha planet can always grow enough food to feed their billions even if it’s in vats or on orbital stations or whatever they might still consider “natural” food items as a luxury or preference especially things like meat and fruit so I can see alpha systems having a demand for those from nearby systems – again stressing nearby.

4) The alpha planets will provide the main market for high value goods simply because their population size and TL implies they will have a large market and lots of prosperous or wealthy individuals.

So the alpha planets are the main markets and provide the hubs of trade.



If you accept the conclusion then the nature of trade in the Imperium will resolve into three main categories:

1) Hinterland Trade

Each Alpha system will have a cluster of systems around them which are tied to that Alpha’s economy. The hinterland systems will generally provide something useful for tech.

  • very short distance, 1-2 parsecs, for low value goods
  • short distance, up to 6 parsecs for medium value goods

The clusters made up of an alpha and its hinterland would once have been the core of the many pocket empires swallowed up by the Imperium as it expanded.

2) Silk Road Trade

Long distance trade between the alphas. Ships plying these routes don’t need to trade with the systems in between so these routes generally take the form of truck stops with an orbital refueling station by an outer gas giant or ice planet. The hub to hub ships just jump in, dock, refuel and do maintenance checks at the space station then jump out again. They only stop to unload when they reach the destination. Silk road truck stops will generally have a small 3I naval base for protection – like a Roman fort.

3) BackwaterTrade

Most everywhere else will have relatively low volumes of trade providing a living for Book 2 type subsidized merchants and Free Traders.



The alpha planets will often have orders of magnitude more people, GDP, tax etc than the rest of their sub-sector so not only will they both physically produce the fleets and provide the revenue to support them – so in terms of fleets – the bedrock of the Imperium – the alpha planets are what matters.

More specifically what matters in order
1) alpha planets
2) routes between the alpha planets
3) border fortress systems
4) alpha clusters
5) everywhere else

This leads to my 3I being split into three layers

  • there is a big ship universe of dreadnoughts and megacorporations comprising all the alpha systems and the silk road systems linking them
  • there is a medium ship universe in the hinterland systems of each alpha cluster
  • there is a small ship universe everywhere else where the 3I is rarely seen

(where small <= 1200-1600, medium <= 5k dtons, big > 5k dtons)


Which systems are which?

You could do it the GURPS way of giving systems a trade value based on their world stats but I think the potential self-sufficiency of systems and the consequent randomness of whether or not a system has something worth selling to an alpha makes a random element to trade value both plausible and potentially more interesting so IMTU I’m going to treat the canon star port class as the indicator of trade value i.e. if they built it there was a good reason so:

1) Alpha Systems: the alpha systems are defined as class A, pop 8+, TL 12+ (and sub-sector capitals)

2) Hinterland Systems: non-alpha systems with A or B star ports within 6 parsecs of an alpha system are assumed to have something to sell to the alpha in exchange for tech and are part of that alpha’s hinterland cluster

3) Exotic Systems: A or B systems outside of an alpha cluster (more than 6 parsecs) will generally have an exotic explanation. It could be something shady, historical or unusual like the system is being actively built up by the Imperium for some reason with regular colonist ships from the core

4) Backwater Systems: C, D and E systems are assumed to not have much anyone else needs and so have a low volume of trade serviced by Book 2 type ships

5) Silk Road Truck Stops: systems that make convenient refueling stops on the silk road.

6) Hinterland Truck Stops: systems that make convenient refueling stops on hinterland routes.


Example: Glisten sub-sector

1) Glisten is an alpha system.

2) Mertactor, Mille Falcs, Egypt, Overnale, New Rome, Aki, Weiss, Dobham are all hinterland systems and part of Glisten’s cluster

3) Romar, Bendor, Squanine, Ffudn are both hinterland systems and silk road truck stops

4) Mithras, as a prison planet is part of Glisten’s hinterland also

5) Grote is an exotic exception system – it could be a system being actively built up by the Imperium as a border fortress and link to District 268 or something odd / shady.

6) Aster, Melior, Craw, Horosho, Wurzburg, Lydia, Centry, Bicornn, Crout, Tirem, Caledonia are backwaters

7) Callia, Sorel, Tsarina, Windsor, Trane, Inthe are backwaters and hinterland truck stops

8) Marastan is a backwater and a silk road truck stop

  • systems like this are part BSU and part SSU and will generally have a commercial orbital station which services the passing merchant ships and small ships linking to the planet itself. Players jumping into the system might see lots of big silk road freighters and lots of patrolling fighters between the naval station and the jump points but very little traffic near the main planet.


Ship Encounters

Alpha Systems
  • very busy, lots of colonized planets and moons, lots of habitats, masses of internal traffic plus lots of large, medium and small interstellar traffic. Lots of planetary defenses – especially around fuel sources. Naval ships up to dreadnoughts. Silk road patrol ships.
Hinterland Systems
  • less busy, medium and small commercial ships, medium naval patrol ships.
Backwater Systems
  • quiet, small commercial ships, belters, scouts, small naval patrol ships.