There's two points tied up in this -- actual difficulty of the different levels, and the random distribution you wind up with. As for the distribution -- I've been thinking of adding a min level setting as well. I take it you'd be interested in that?AI: easy-to-medium difficulty - even on manical. Probably personality distribution; it's cool that there's a random chance for a hard game, but when it's too easy... ya feel a little cheated.
As for actual difficulty, yes, there's a long ways to go, and the rate of change in the game lately has been impossible for me to keep up with; I don't think the AI is currently as challenging as it had been. My basic target is to get all the various planning tuned as optimally as I can, and for the most part set that as the 'moderate' AI behavior. There are a few things that I save for the Aggressive and Maniacal AI's so they have some basis to be actually harder, and they'll also initiate fights that are less clearly in their favor. I should probably step that up even a bit more for the Maniacal AI now; my goal for it is that it really does come off as Red Hot Crazy, but actually too much so, so that it ideally *should* wind up easier to beat than Aggressive.
I had been hoping to mostly just distinguish Turtle and Cautious AI's by having them require larger margins in their favor before starting fights, or when planning defensive assignments, but that didn't seem enough so they also get hobbled a bit on tech's that can, from a storyline perspective, be considered 'risky'. Examples: A Cautious AI (and Turtle& Beginner) will not use a Black Hole Generator. A Moderate AI will, but will not consider making an Artificial Black Hole. Turtle and Beginner AIs will not even use a Solar Generator.
So there is a very significant extent to which the aggression levels are in fact enforced as difficulty levels. The fact that it's hard to notice, and that in fact, a Cautious AI can often outperform an Aggressive AI, is pure testament to the significance of the randomized galaxy layout and plain luck. I've gone ahead and committed by charting script to SVN to help anyone like you interested in better visualizing AI performance (and your own). Comments in it explain possibly-nonstandard modules needed and how/where to run it.
I think I posted the list when I started, but here it is again: Ivory Tower is for the Theory guys with no practical experience (Beginner); Citadel is for the Turtle; Bastion of the Brave is for Cautious; Haven is for Moderate; Royal Demesne is for Aggressive, and Throne of Heaven is for Maniacal. The charting script will also clearly identify the various empires by name augmented with starting Race and Aggression level (see below).Can't tell difficulty of AI opponents.
What difficulty do the AI homeworlds name map to? aka: Haven = what? Ivory Tower = ?
Yes, absolutely now, whereas in the past, not. The AI is only moderately adapted to the current colonization costs/dynamics, in a conservative way so that they dont get too much resources tied up in colonizing low return planets. My whole valuation of planets for them is still a bit off balance as well, though in many respects its much more advanced than it had been. This is just an area that's going to need a lot of work before Im happy with it, and the rules are ever changing.AI seems to pass up habitible planets
Yes, I've noticed this to a surprising degree as well but havent got it fully resolved. At least many times it's because the number of ground troops advanced past what the AI had allowed for & so it doesn't bother with a partial invasion; I'm still working on the full handling of that.Invadable planets were not invaded
I dunno; I'll try to keep my eyes open for such.An exobot ship was hoving over an asteroid belt (where the AI had an outpost)
Just for fun, I'll attach the PP chart for a test game I accidentally let run longer than planned today -- I got tied up in various things and came back a few hours later to find it on turn 423 The base galaxy was 200 systems, mature, everything medium density, 12 AIs. The winning AI had taken over the galaxy (looks like it had finished off the last opponent around turn 340) and had a per turn PP production of about 15k, and an armada of something like 10k Sentients loaded with Death Ray 4