I've been playing the latest 1.1 beta on cripppling level. AI is really giving me a run for my money. I'm surprised by how smart its getting with research and trading. Its now very hard to get weapons tech from the AI. I've also noticed that its hard to get propulsion tech. The AI seems to value it quite highly. Defense tech seems fairly easy to pry away. Anyhow, I digress. My latest strategy is a bit of a script:
1) Research up production tree:
Planetary improvements, Xeno economics, Xeno industrial theory
2) Research up diplomacy tree:
Xeno Communications, Universal Translator, Diplomatic relations (build diplomatic translators!)
3) Research up government tree
Interstellar governments, Alliances, Interstellar republic
4) Research Xeno Ethics-neutral (build harmony crystals)
By this point, my economy is set. The interstellar republic gives me lots of money, taxes are high because people are happier due to Neutral alignment and harmony crystals. However, I'm way behind in terms of weapons tech. The AI have been working along those lines. Rather than play catch-up, I look for the brightest of the bunch (yet stupidest diplomacy-wise) and trade for their highest level of weapon. Its expensive, but I can then continue research from that point. The lower technologies can be acquired later through conquest or more tech-trading. Also, those government bonuses are pretty valuable items--Alliances and Interstellar governments. They give very minor bonuses in and of themselves, but make good bargaining chips, since no AI has even attempted this tech branch yet. I trade away all but Interstellar Republic, and end up with weapons. The AI players rarely go to the republic until later in the game, so I haven't given much away. Repeat for defense tech.
Propulsion tech is really wierd. AI players don't seem to want to pay more than average for it, but they sell very dearly. I end up researching it most of the time. Occasionally I'll tech trade to leapfrog to the important techs of impulse drive and warp drive.
I've also noticed that the AI is very stingy with soil enhancement and habitat technologies. Being neutral, I never research these techs myself, but I do like to get habitat to build aphrodesiac. Strangely, in the last three games I've played, the Drengin always seem to be the first ones to these techs. They never want to trade, though. Occasionally they will build the aphrodesiacs. These are even harder to trade for than habitat. Might as well bite the bullet and buy it as soon as it is available, so you can be the first to build it. Of course, second place sucks--you end up buying the tech, sink money into the trade good, then lose it all when an AI player builds this valuable trade good first. The last two games I've stuck to diplomatic translators and harmony crystals.