Thalans (played by AI) seem to expand like crazy in every game - daunting

They are somewhat limited in what they can do in the early game. So they tend to build lots of colony ships and embassies. The Pink Blob of Doom strikes again!

The Pink Blob of Doom... /cackles. It (the Thalans and my phrase) shall never die!!!

Oh, and as Piznit said, Idle Hands make them focus on buildings ships since there isn't anything really to do on the social front. Try a game of Battle of the Gods with them in it and things would be vastly different.

I am playing gigantic game, but the thalans are not an issue, in fact they are not even building ships?

In my games it´s alway the terrans which dominate (well besides me :P)

The Thalans also get a few galactic wonders from the start, which give a real boost to production on the home planet, when i play as them i just pump out colony ships (not much else to build in early game with Thalans) for ages.

Try playing Thalan. You'll figure out why this happens real quick.

At first they don't build ships, then, they sudenly become the magor power in the universe. It,s even worse if you make them smarter.

Their major weakness is espionage on those nice super buildings + their economy (their manufacturing and research buildings have a maintenance cost of about 1bc per production/research point, far more than other civilizations).

Only the +25 econ building is susceptible to spies. The morale building and the Hyperion Matrix can't be shut down.

I've been playing a huge galaxy game at tough difficulty with the Thalans lately and I find their power is absolutely mind-boggling if used intelligently. I started out by choosing abilities which nullified their population growth disadvantage, added to their economy, and industrialists government .. if I'm remembering correctly, +10 pop growth, +53 soc/mil, +10 econ, in total.

I did not, for a long time, have to at all build manufacturing matrixes, and when I did start, for the longest time I pretty much only used them, and the technology matrixes, on bonus squares. All worlds got star bases to begin with because there was nothing else to build and soon I was churning out small ships and constructors. With a lot of well placed markets/stock exchanges, and a trade for a +2 food farm, I had no problems. My empire only got better when I went evil and got the brain washing complex; the thalans can have sick, sick influence, even without concentrating on embassies.

Let me tell you that a manufacturing matrix on a +700 percent tile will either bankrupt you or be your capital ship-building planet forever. It's my personal opinion, after this game, which I'm just mopping up now, that the thalans are born and bred conquerors and that you will not need to build a lot of infrastructure to do so until your economy can handle it.

Thats true. They have a hugemongous amount of civ-wide bonuses to production. I usually do a major colony rush, fill my worlds with econ buildings and then add factories here and there as I can afford them, maybe devote the smaller worlds to labs.

I don't even use +pop growth, I prefer taking +econ and +morale. With %100 approval you can crank out colony ships like nobody's business and keep your economy afloat till you get your pop up, as long as you keep maintenance down.

To match Thalan colony-spread requires any race you play to be creative with the ship builder to make cheap colony ships and pay attention to techs that allow military production advantages. I find that I tend to pay more attention to factory production, buying factories, and upgrading factories than other buildings early on. Getting as many colony ships out and exploring as quickly as possible and nabbing the best planets as quickly as possible. You might not be able to close the gap with the Thalans, but you can get close to their prolific ways. The rest is up to the randomness of the galaxy on planet types and where habitable planets lie. When I play the Thalans, I find my expansion capability is roughly similar to what I experience with aggressive play with the other races, but with the Thalans, you pretty much fall into that pattern as a default rather than having to force it like you do with the other races.

I've played a bunch of games where I do absolutely nothing, sitting in a corner, and let a half-dozen AI races fight each other.

There's only ONE thing that gets the Thalan - early agreessive tendencies by the Drengin or Korath.

They have a large area, but it's completely (or virtually) undefended!

Yeah, I love how a base attack of 18 goes to 44 with all the passive bonuses . One weakness the thalans have is their soldiering. At best they're average unless you steal the tech from other races.