This mod allows terraformation of Gas planets into telluric planets: Gas Burning -> Lava; Gas Hot -> Lava; Gas Warm -> Lava; Gas Temperate -> Ice; Gas Cold -> Ice; Gas Frozen -> Ice. Those are available once first tier terraformation technology is researched; the Gas Giant must be colonized first, of course. The size of Lava/Ice planet will always be Huge, no matter what size was Gas Giant (which I think makes sense and is lore-friendly, since Gas Giants are usually much bigger than telluric planets). These new planets can be further terraformed, they are same Lava/Ice planets that are generated in galaxy right from the start.
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