I just bought the game Thursday. I have only played as humans and only at normal difficulty. Stumbled through my first three games as the biggest loser in the galaxy, then implemented the following strategy based on what I saw the AI doing.
1. First set my home planet starbase to build colony ships, use the premade colony ship to colonize the other habitable planet in my system
- This planet (usually Mars since I’ve only played as humans, a lame lvl 4 planet) is my research planet. I build only research labs on it.
2. Reorganize my economy so that the tax rate is as high as possible with my approval rating still in the low 60s. Balance out the econ sliders so that 40% is in military, 40% in research, and 20% social. I never change this setting unless my people get so upset they start causing trouble. In that case, I lower taxes until I’m in the high 50s again.
3. Que up to build three factories and three labs on my home planet in alternating order.
(1-3 should assure that your home planet is producing ships reasonably quickly and that you don’t fall behind the tech curve)
4. Use my initial survey flagship to examine all surrounding star clusters. I move in a circular motion from my home system. Ignore anomalies unless directly in your path. They are not worth wasting time to pick up and if you get unlucky, stumble unto a wormhole and lose your surveyor, you now start with a handicap.
5. For every habitable world my survey ship finds, I immediately buy a colony ship and send it out. I do not wait around to build it. If you set your taxes high enough, your initial starting money should be enough to buy several colony ships without going into debt. The only reason you have your home planet starbase set to build colony ships is so that they'll be slightly cheaper when you go to buy them.
6. Use planet bonuses to decide what to specialize in on a planet. I focus mostly on research planets at first then manufacturing planets to build ships later when I need them. Distant planets stuck in the corner of maps are good for econ planets since enemies are less likely to invade them and the long distance makes for profitable trade routes. (I think, I'm not positive on how econ planets work since I don't focus much on them). Mostly you want to make sure you have a few big planets that, when they mature, will be able to churn out ships at the rate of one every two to three turns.
(4-6 should put you in a strong position to win the game unless you get unlucky and all the good planets are in your opponents backyard. Whenever your home planet isn’t building colony ships, it should be building construction ships to build military/economic/influence bases on the resource spots)
7. Research cheap things that look helpful. I usually research all the early stuff except space cartography and farming techs. Universal Translator is vital so that you can communicate with your opponents. I accept most trades that don’t involve me giving them military techs or engines/life support (I don't want to help them travel faster/further across the map and thus maybe beat me in finding planets to colonize).
- More importantly, in the diplomacy screen, I examine my opponents' military techs to decide on what route I’m going to research. If, for example, I see the Drengin have beam theory and armor theory up for trade, I immediately throw my research into beam/missile theory and shield theory. This way I can counter them (beam weapons are blocked by shields, armor is easily pierced by beams and missiles but blocks mass drivers). How do you know which race to focus your efforts against? Just pick the one most likely to be a threat--one that shares borders with you, is outpacing the other races in population, and/or is naturally hostile.
8. Once you see your enemies are beginning to build warships, custom build your own ships to counter them using the above advice. The default warships kind of suck, so ignore them. You’ll have a bigger advantage if you custom to your needs. Researching logistic, miniaturization, and life support are also very important so that you can form fleets, fit more gadgets on your custom ships, and travel further. Nothing is more annoying then finding you can't harass your enemy on their home turf because you forgot to build life support on your battleships and so can't reach them.
9. Every time I meet a new race I put exactly one BC into spying on them. It takes a long time to get anywhere, but that's alright. The only really worthwhile things my spies tell me comes later in the game--when they let me know exactly what defenses and ships are surrounding my opponents planets.
With this method I have completely destroyed the AI on normal to the point it’s not even a contest. Possibly at higher levels it may not work so well.