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:
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:
All services, including major shipyards.
All services, including shipyards.
Limited services. Repair facilities only, no shipyards.
Very limited services; spaceport is fenced in and has basic security perimeter. Fuel available, but no construction and extremely limited repair facilities.
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.