Personally, I usually make them economy worlds. However, I just got a class 5 planet in my recent game with 3x 300% Research bonus tiles.

I just fire and forget with research buildings. I don't even build a factory - I just plop down 3 basic labs before researching Xeno research and let them build/upgrade themselves as the game unfolds.

Right now that's my standard M.O. 1 farm, 1 econ-building, 1 morale-building. On a PQ 4 I will add a embassy, on a 5 I leave a space for a specialized building like eyes of universe or rest. of eternity.

But is this the best use of space?

However, I just got a class 5 planet in my recent game with 3x 300% Research bonus tiles

This is the main reason that I DO NOT overlook smaller PQ planets. I see a lot of people in here who do, and if it works for them then great, but the possibility of those bonus tiles coupled with terraforming make them worth the effort in my eyes. I don't really crunch all of the numbers when it comes to individual planets and their maintenance costs since my economy is almost always running well in the mid to late stages of the game. In the initial rush however, sometimes you are best to avoid the lower PQ planets just because. But once you are up and running you should grab all of them that you can. If you find that the planet is pretty much useless to you, you can always disband the colony and leave it a worthless hunk of real estate.  

The best you can usually do with these is as Gre_Magus said. Just put research down on them and forget them.

You can put 3 factories and a starport on a PQ5, but it's really only good for building constructors. If it has some good production bonus tiles then it may be good enough to produce small fighters but it'll never be good enough to produce end of game capital ships, they'll just take years to build. You could use these to build colony ships and transports but these planets don't grow enough pop to fill them up.

A farm is a waste of a tile on a low PQ planet. The Wiki article lists the following limits on the growth of low PQ planets.

PQ4 = 2.5B
PQ5 = 4.3B
PQ6 = 6.9B

Yes, if you put a farm on one of these you could bus pop in with colony or transport ships but what would be the purpose?

You can put stock exchanges on these and they will generate a net income, but since the income is based on pop they're not really good for this either.

The best thing to put on these is research because it's not population dependent and there's no real need to have research concetrated on a single planet.

Sometimes I'll start out in the early game using these as producers of my first ships because they aren't that expensive then later on convert them to research when my ships become too expensive to produce on such a small planet. But usually it's just set to research and forget.

On PQ 3, 4, and 5 planets, you can never have more than 5 billion people. Building farms won't help, as the population simply stops growing before it hits 5 billion. As a result, morale buildings are unnecessary on those planets, too.

depending on tax rate


2 econ, 1-2 moral

3 gets 2 research
4 gets 2 research 1 economy
5 gets 2 research 2 economy
6 gets 1 farm 1 morale 2 research 1 economy.


That is not necessarly the build order though.

I use them. If they have bonus tiles for research I'll use those. If not, I throw markets centers or later in the game, stock markets on them. They can make some bc so they're not worthless. When they have a good manufacturing bonus, I'll build factories on them and use them to build special projects.

In order, the uses I have found for them.

1) If you are buying a special project, put it on one of these.
2) If it has other, high quality planets nearby, buy spin control and omega defense on one and remove the shipyard. This way you can stack ten ships in orbit and not lose any real production. Really, it's now an oversized military base.
3) Build constuctors.
4) Econ buildings.
5) If you are towards the end and buying ships. Buy them on these planets first as you will lose one turn of military production on any planet you buy a ship. (It fills the production bar to 0, but takes a turn to produce the ship. Since military production isn't rolled over, you lose military production the turn the ship is produced)

Actually if there's a big planet and a small planet in a sector, I take the big one, wait for someone to colonize the small one, then culture bomb to flip it.

wait for someone to colonize the small one, then culture bomb to flip it.

This sounds great but then you have the hassles of changing what they've built up... if you don't like what they've done with the place that is...like someone painting their whole interior of their home PINK!!!! WTF is up with that?  

I put labs on my worlds with low PQ. Labs perform exactly the same no matter where you put them, the only exceptions to this are the tech capital and boosts from economy bases. So labs work just fine on planets with low PQ. Labs and markets both need other types of buildings to be fully effective, so they aren't good candidates for the poor worlds.

The taxes produced by a planet are proportional to the population of the planet multiplied by economic bonus from markets on that planet. So, to maximize your tax income, you want to put a high population and lots of markets on the same planet. This is only possible on a planet with room for lots of markets, farms, and morale buildings, plus planets with high PQ get a free morale bonus. So I make my best planets specialize in economy.

Factories need a starport on the same planet to be fully effective, and a starport needs more than a few factories to be worth a planet tile. Put those factories on a planet where they'll also be able to contribute to social building. And put the starport on a planet that has more than a few factories. I make my middle-quality planets do both production and reserearch.

On those planets with PQ 3, 4, 5, or 6, only labs are fully effective.

I put super projects to the smallest planets. I don't build them, I buy them. Eyes of the universe, terraformer, spin control and hyper computers are good candidates. I'm surprised no one else mentioned this.

If you can crank your economy to the point where you can afford to buy them before the aliens build them, then I tip my hat to you.

That's a luxury I've seldom encountered.