In the Traveller setting there was an earlier human Empire which collapsed. The current Imperium was rebuilt over the top of the previous from the same core. So imagining the situation 200 years after the collapse what kind of planetary options would there be?
1. Core worlds – as before
2. Colonized worlds where the colonists die out during the collapse – hostile mining worlds, planetoids etc – so lots of ruins.
3. Colonized worlds with a native prestellar species where the colonists might have died out or been killed by the natives or become like the natives or enslaved by the natives.
4. Colonized worlds where the colonists reverted in technology.
5. Colonized worlds with a prestellar native species where the colonists reverted in technology – maybe to the same level as the native species or still above (see Jorune or Tekumel).
6. Non-colonized worlds – maybe with a science base or two – with a prestellar species.
7. Other non-colonized worlds.
This setting could take one of the existing Imperium sub-sectors near the core with their exisitng planetary profiles, ignore the government, tech level, starport stuff and just keep the physical characteristics: size, atmosphere etc with the players operating at the edge of the expanding Imperial frontier whether for some official part of the Imperium , a commercial org or as freelance antique hunters looking for Vilani artifacts.
Dividing the planets into three categories: habitable, habitable impaired, uninhabitable and assuming the original subsector capital was the best planet some random tables might be:
sentient alien species: habitable 8+, habitable impaired 10+ uninhabitable 12+ (these last would generally be very weird e.g. lava creatures.
previous colony: habitable 8+, habitable impaired 10+ uninhabitable 12+.
If previous colony and no sentient species, colony survived: habitable 8+, habitable impaired 10+, uninhabitable 12+ (a surviving colony on an uninhabitable planet may have survived in a strange form e.g. tunnel dwelling cannibals)
If previous colony and a sentient species: hostile relationship 2-5 neutral relationship 6-8, friendly relationship 9+
hostile relationship: habitable survived 10+, habitable impaired 11+, uninhabitable 12 (maybe in some strange brain in a jar type form)