Psion
Adventurer
Ariakor said:I'm just going to use the starship combat rules and probably some of the design/equipment rules (as well as those for generation star systems and such, because that is lacking in d20 future).
Well, it's more extensive than d20 future, but can still produce some planets that technically aren't feasible (i.e., below a certain size (~4, IIRC), you will not have atmosphere better than trace in the habitable zone.)
If you are really concerned with such nitty gritty details about planet generation, the best book currently on the market is First In for GURPS, and it's not that hard to adapt the results to T20.
Alternately, a quick fix I use (since I use existing data from Gateway to Destiny) is to re-define the size digit the represent mass (1=1/8 earth mass), which handily eliminates most of the problems with technically unfeasable atmospheres and lets you use existing data, though you will have the recalculate things like gravity.