My first game was a small universe on beginer. Increased the difficulty every game. Now I am almost done with a large map on crippling. To be honest, I haven't found the AI tough to beat yet. I don't restart, and don't use the cheesy transport raider either. If the final version of 1.1 isn't available before I finish this game, then I will go to masochistic.
The tactics I use are nothing special.
1. Tech whore like crazy, especially early on. The AI rarely refuses to trade a tech for something. And if it wont, then there will be a minor that ends up with it in a few turns. I personally don't care if I get a bad deal from the AI. Eventually, it will settle out and I will be No.1 in tech. Happens every time. In Civ, the computer guarded techs very carefully. I guess this could be considered an exploit and perhaps that is why there will be an option in 1.1 to dissable tech trading.
2. Always attack a weak neighbor as soon as possible. In Civ III, this could be risky. An unlucky string of attacks could throw everything off. And if you ran out of attacking units, there is nothing stoping the AI from comming back at you. Basically, it didn't need transports. In CalCiv II I will always kill a minor if it ends up in my territory. Once I have Planetary Invasion it is all over. And there really isn't any chance to it either. For example, a 10,000 population planet may take three transports. So go one higher for good measure. And this is just using conventional warfare. If you get unlucky, use a different form in a desperate situation. Also consider advantage factor when determineing No. of transports needed.
3. Suprise the computer. It isn't hard. Just mass up your forces. concentrate on transports, because they are really what you need. Make them fast, and make their escorts very offensively powerfull. Go charghing in, bypass any enemy fleet and go right in for the planet kill. Once the planet is yours, it is relatively easy to keep because you will most likely be able to pick off the counter attack transports. Again, speed is important here. Several times, I have completely killed an unsuspecting AI in just one turn. It takes a lot of planning, but it isn't hard. And then when there last planet is dead, all there forces vanish. So again, why bother attacking them. Just another little pointer: sell all your available techs to the unsuspecting target right before you kill him. That way, you get a lot of his money too. Ya, it is cheesy.
4. By always attacking the weakling, you get a critical mass. Don't really know what else to say here. Bigger is always better in 4x games IMO.
5. Use the diplomacy to your advantage. Definately don't overestimate the computer. He is not that dangerous. If a powerful empire declares war on you then even the odds with diplomacy. Do whatever it takes to get other AI's to attack the aggressor. I have found it really isn't that difficult. Weak ones will probably refuse, but you can most likely at least get one to join in on your side.
6. Speed is a killer. The current AI is too slow. I recognise this is being looked at.
7. In my oppinion, basic planetary imporvements are the best. Capitols are good, but I don't bother with galactic wonders or trade goods. The goods I can get by tech whoring or conquest, and the wonders I can get by taking them by force. All that production power is better spent on ships. Just my oppinion.
8. This isn't my idea, but it works great. Pack a transport with as many sensors as possible, then put one next to a planet in every system. They are cheap to make and keep you from getting suprised. Ya it is a transport trick, but at least I am not killing things with it.
9. In my oppinion, economy, moral and diplomacy skills are the best. I concentrat all my points on these three. Then I use the populists as a government. Someone did a thread and rated the governments. I was suprised when I saw that the populists had the highest numerical rating.
I think that with practice, anyone could beat this on suicidal. I have been playing these civ type games for over ten years, and I haven't found this one to be horribly difficult. These are just my takes on some possible strategies and are difinately not to be taken as gospel. I am also not doging this game in any way. Just a friendly commentary really.
I am confident that 1.1 will be an improvement.