Tag Archives: Planet

How Many Colonists Does It Take?

One of the big questions you face when working on an interstellar science fiction setting is: Just how many people does a colony start with?

Cue this timely article by Popular Mechanic. They assume colonization by generation ship, but I think the results are still applicable if you simply look at the colony at its destination. It takes between 10000 and 40000 people to maintain genetic diversity and guard against accidents that wipe out a substantial number of colonists. As a side note, the authors also recommend that it’s better to send a small fleet of vessels rather than one big ship – but that sort of redundancy is pretty much a given if you are sending that big an expedition.

10-40k is a really good match for population characteristic value 4 (“tens of thousand”), and you could assume that any world that has Pop 4 and a TL that is close to your setting’s mainline technology level is a fresh young colony – especially if it’s out in the periphery.

At first glance it might seem that colonies are big busy places – forty thousand people is a fair-sized town – but keep in mind that this is the entire population of an entire planet. They’ll spread out at least a little bit, into homesteads, camps, and outposts, and the main settlement with the starport won’t be a very big settlement at all.

It’s also worth noting that 10,000 individuals is the assumed number of survivors during the Toba catastrophe human population bottleneck.

For comparison: Concord, NH has about 40k inhabitants. Caldwell Parish in Louisiana has 10,004 inhabitants. Its largest town, Clarks, has just over 1000 inhabitants.


Government is determined by 2d6-7, adding the population characteristic. The result is then referenced to a lookup table; the concept seems to be that smaller populations are more liberal, anarchistic – or less independent – while large populations require more bureaucracy and tend towards repression (which is also reflected in the Law code).

There isn’t a whole lot that can be done to create “realistic” societies with dice rolls and, consequently, I will use the Traveller table as-is unless I find fault with it later.

The governments are, according to the SRD:








Participating Democracy


Self-Perpetuating Oligarchy


Representative Democracy


Feudal Technocracy


Captive Government (or Colony)




Civil Service Bureaucracy


Impersonal Bureaucracy

10 (A)

Charismatic Dictator

11 (B)

Non-Charismatic Leader

12 (C)

Charismatic Oligarchy

13 (D)

Religious Dictatorship

Government is probably the first thing the GM really needs to adjust to his setting. Keep in mind that there is also often more than one way to describe a government. And what a government officially calls itself does not always reflect reality; the USSR and the PRC come to mind – or the German Democratic Republic.

Colony/Captive World

When the dice come up with a colony/captive world, I always look around to see what nearby powerful world (Rich, Industrialized, High Tech, and/or High Population) could be responsible. In my first sector (not the Trial Run subsector) I ended up creating a handful minor states this way.