I´ve been looking over my various old attempts at star system generation rules lately, and revisiting the threads on the topic. For some reason, my mind just can´t let go of the topic in the long term. Nor can I ever be happy with the strongly mainworld-centric approach of Traveller and its derivatives (such as Cepheus).
For some reason, I can feel the beginning of that fabled "wisdom of old age" thing setting in - so rather than dive head-first into building yet another rule set, I decided to first figure out what I want out of such a rule set, and what sort of rule set can do what I want it to do.
Firstly, I want the rules to generate a system from the ground (i.e. the star) up, not from a mainworld of whatever kind. Call it the heliocentric rather than geocentric model if you want.
Secondly, I want the rules to be simple enough that the average Referee or other worldbuilder (reasonably educated, but neither a scientist or engineer nor a mathematician) can do any required math in their head, that any random elements can be determined with commonly available dice (ideally, spectral subclass is the only part where you use dice other than d6), and that even without an Excel spreadsheet full of formulae, it is possible to build a complete star system in a reasonable amount of time.
Thirdly, while I don´t need this to be ultrarealistic (I´ll leave that to the experts), I want the results the rule set produces to look at least semi-realistic, which (among other things) means:
- reasonably realistic distribution of spectral and luminosity classes among stars
- planets are not strewn haphazardly around a star, but follow a reasonably internally consistent logic in their placementt (even if that logic is not the cutting edge of planetary science)
- only a fairly limited range of stars can actually harbor life-bearing worlds
- life develops only where it makes sense for life to develop (How did Arrakis or Tatooine or Hoth get an oxygen/nitrogen atmosphere? How did the titular Planet of the Apes have time to develop in orbit of Betelgeuse which is less than 10 million years old?)
- not all life-bearing worlds are habitable to humans
- most worlds that are habitable to humans are fairly unpleasant places for one reason or the other; those that are not are therefore quite prized
In addition, I think the litmus test for a star system generation rule set should be that, at least in theory, with the right dice rolls, generate something that bears fairly close resemblance to our own solar system, at least to the layman.
...okay, gotta deal with some other stuff first. I´ll post more later, starting with generating the stars themselves. Hope we´ll have some good discussion on that.