It says it "converts standard and fertile planets to gaia environments for a cost of 300BC"

Except that in my current game as the Silicoids it is not allowing me to transform any planet, fertile, standard or not!

I've played MoO1 on and off for nearly 30 years and don't remember coming across this!

As a counterpoint to their ability to colonize any planet since the beginning and ignore waste, the Silicoids cannot use the Soil Enrichment and Atmospheric Terraforming technologies. They are not able to research them on their own, but if they obtain them through trade or espionage, these technologies won't do anything.

Yes, the big drawback for the Silicoids. They play almost nothing lke any other race in the game.

IIRC the Silicoids are kind of bugged.
In theory they don't care about waste and pollution, so it seems weird that it should be more expensive for the Silicoids to buy pop, since they are the one race that really needs to do it in order to prosper.
Also, I think they don't get any of the techs that help reduce pollution or reduce cost of cleaning, which (if I'm correct) means the cost of buying pop gets even more expensive. Seems like a design or programming error for the Silicioids to have to get past Clean on the Eco scale before getting to + Pop.

I just tried it, and the Silicoids don't need to clean up pollution in order to pay for faster population growth. While the game says "Clean", it doesn't actually remove any pollution if you invest in growing population faster; that spending is instead applied directly toward population growth. The game just shows "Clean" to indicate that you aren't getting extra pop next turn with that level of expenditure. It doesn't look like the Silicoids are able to clean up pollution.

I tried navigating through several turns of pop growth (throwing extra into Tech) with Silicoids and with Humans to try and compare, but it's goofy because of natural pop growth. Silicoids do seem to need to spend more to start showing "+x Pop", but I think that's because of their inherent growth penalty. I can't tell if there's an extra penalty for buying population, but I never saw anything to that effect when I've read the manual and other web sites about the game. A first turn investment of about 20 production did trigger +1 Pop, so it kind of feels like Silicoids don't pay more for vat grown colonists; it may simply feel like it because natural growth isn't doing much to assist.

The Silicoids are easily my least favorite race. I don't like playing them and I don't like playing against them.

Thanks for the clarification, Bookwyrm. Good to know it's not a bug after all.

The Silicoids have halved population growth and the Sakkra have increased growth and the Sakkra behave like they have built in cloning, meaning cloning population is always cheap and easy. I very rarely play Silicoids so did not see any increased cost, probably just missed it. The cloning tech is worth a lot to the rocks for sure.

It is a pretty interesting subject. Quoting from the official manual it says this about the Silicoids:

"immune to the effects of waste and can land on star systems with any type of environment" and also:

"Even though the Silicoids already possess many of the planetology tech advantages, Silicoid players cannot ignore planetology altogether. Planetology is necessary to expand the size of planets, and the additional production bonus is always important."

It does imply planetology tech matters to Silicoids in the regard they can use it to increase max pop of a colony, which obviously contradicts actual gameplay. On a side note it is a pretty amusing wording regarding the explanation why planetary enhancements increases the pop cap. It is as if not really due to the ecology being improved giving more habitable land and superior arability, but rather it is in fact the entire planet literally having expanded in size. LOL

Fun fact: In the MoO prototype the Silicoids' maximum colony population is not affected by planet habitability. Here they can always reliably support 200 inhabitants no matter how inhospitable the colonized world is. Likewise Silicoids also happened to not be excluded from acquiring otherwise redundant planetology tech via research. At some later point that access might have been seen as unnecessary to them, hence giving a possible reason why the devs made those unavailable to the Silicoids.

Meanwhile, having Silicoids practically viewing every planet as a Gaia world is probably quite imbalanced, so it makes sense a rebalancing was issued by requiring them also relying on planetology tech for max pop upgrades; which would explain the current description in the official manual. Somehow it all ended up with the Silicoids we are familiar with today that can neither do terraforming nor research such tech themselves, but without the user manual getting that update accordingly.

Silicoids DO get the +10, +20... up to +120 but not the others.

Wouldn't these techs be useful for captured populations? In that case it might sometimes be a disadvantage that these techs can't be researched.

I was previously confused about planetary tech, having forgotten its mechanics. Indeed, Silicoids are indeed not entirely without an ability of increasing max pop. It is just that in the prototype they behave pretty much as one would expect based on the game's limited lore. That is they are a hardy species that don't need any ecology upgrades to take full advantage of a planet's surface, meaning the purpose of terraforming is completely unnecessary for them. Admittedly, that trivia isn't really relevant here.

Capturing populations isn't a thing in MoO1. One has to completely eradicate an alien population before that colony can be captured or recolonized.

Ah! I got confused about the game under discussion.