[Suicide Junkie]

IMHO Phoenix-D is right about the MMH. I don't see why adding lots of variables to the planets will make it any more interesting. It is just more moving around people for the best location.

I think the important part of this idea it the fact that it would allow for one race's terraforming to become another race's environmental catastrophe.

If we had separate variables for gravity, radiation, temperature, and various atmospheric gasses, it wouldn't be any more complicated than it is now.

You'd just build a terraforming facility, and each year it would tweak each variable 1% towards your race's ideal settings.
Add in a small, natural, unterraforming factor, so that planets will return to their natural state if left alone, (and also limiting the terraformer's maximum conditions change as it fights mother nature)

A Rage world with a Terraformer (vaccuum breather machine race) would start reducing the pressure of all the different gas types, shift gravity and temperature to average values, and reduce radiation.
A Terran world with a Terraformer would shift gravity towards 1g, temperature to 25 degrees C, and shift radiation towards the low end, while Increasing oxygen pressure and decreasing all others.
It would all be automatic when you build the facility, just like atmosphere modders now.

Planet Images would change whenever a new gas takes over the top concentration (or when the total pressure drops to a certain value).

Your planets would fall into a few categories:
- Very nice planets, naturally fit for your race.
- Terraformable planets
- Poor worlds that will always require a dome (facility).
- Enemy-held worlds that are very nice.
- Enemy-held worlds that were very nice until they were terraformed by aliens.
- Enemy-held worlds that were marginal before being terraformed even worse by aliens.
- Enemy-held worlds that will never be livable by your race.