I've been reading stuff like this and this, trying to figure out how I can better control planet probabilities in my TWA.

A few people have suggested that Gold planets beyond the standard ones all have the same probability. If I disable all the standard ones and replace them with higher-numbered copies, will they all have equal probability?

In my experience.... NO. JP is talking about adding more control in a future release but not as of now.

Hrm... I knew you couldn't delete the default planet types, but you can't even disable them. So much for that idea.

It was a bit tricky expanding the planet count without drastically changing the planet probabilities. What I decided to do was block off a 10% chance for receiving an expansion planet type. Basically, if you roll between 90 and 100 on a probability roll, then there's a 20% chance you'll get the standard Vaporous/gaseous, or if you roll 100 you always get it. The other 80% of the time, you then roll for an equal probability of receiving any of the expansion planet types. So yes, there basically is an equal chance that you'll receive a Gold planet type.

I will consider ways to provide more control over planet distribution. At the time I had so many things I was adding that I just went with a quick implementation for expanding the planet generation probabilities.

That makes sense. Until there's more control, I think I'll create additional copies of one or two of the more desirable standard planets. Then players will have at least a 5-10% chance per gtorp of getting them with the overloading method Cruncher suggested.