AI Difficulty Levels?

[xeren]

Is there a description of what changes at each AI difficulty level? Other than 'higher is harder'? Eg, what's the difference between 6 and 7 (since you tout 7 as a big improvement), and 7.3, 7.6?

[x4000]

There isn't an overall description of that, and in fact I don't have a comprehensive list of that sort of thing.  It's hundreds of little things between all the various levels, and a lot of the things that are changed are programmer-y seeds that would be pretty hard to explain what difference they make, unfortunately.

[Captain Cake]

One thing that changes with a higher difficulty is that the AI reaches higher tech levels faster. LINK

IIRC the number of ships the AI gets for anything also goes up the higher the difficulty, more planet reinforcements, bigger waves and larger CPAs. (If someone could confirm this that'd be great, not 100% on it)

As for tactics and strategy that the AI uses I think your best bet is going to trial and error. Even with a list of differences it wouldn't really do you much good unless your saw it in action imo.