That gives perfectly logical reasons why Ai wouldn't expand in certain circumstances.

I remember reading complaints that in GalCiv2 the evil races didn't expand - sounds as if this isn't an issue here.

This has been my finding as well. The primary issue is lack of opportunity. I stopped using the maps that can cause these issues, the clusters, and play specifically on spiral (which does a good job) and scattered (which is a little bland but the best).

One thing I have noticed however, and your post kind of corroborates it. The Iridium tend to do terribly, always. So I took a peek into the factiondefs.xml wealth prioritization was weighted between 4 and 8x higher than anything else. This might explain why the Iridium AI tends to be terrible no matter the circumstances.

Hopefully in the 1.01 patch where it says they added "General AI strategy improvements", it fixes or at least helps in some way what the AI doing, like not colonizing.

But since it was annoying me in my game I did some tests and this may just be a coincidence.. but I was able to fix/kick-start the races I was noticing that at a point had stopped expanding.

Now there are so many odd factors that contribute to this, so it could be just one of them or some combination of it all that is stopping the AI from continuing to colonize after a certain point.

I had noticed, the Thalan, who had stagnated compared to the other races, had extremely low approval. So I traded for free the early specialist tech that gives a flat +4 Morale.. and what do you know a few turns later 5 new colony ships were built and on there way to the close by planets.

Using the god mode cheat what I noticed was that all the Thalan planets were focusing on growth, there home planet for example had 4 second tier2 farms giving them a total possible max population of 48, and they were in the process of building another one! but they only had 3 morale. now they did have a pleasure park on there home world but because it is broken and not giving Moral but giving 6 gold im guessing the AI assumed that it had built enough moral improvements. Now this may just be a specific problem with the thalans so i looked at the other possible contributors.

Another major issue im finding that is hindering the expansion is the Pirates, the Ai is just unable to deal with them in a meaningful way in most cases. I watched early on the AI try and send colony ships to planets close by and as soon as they see the pirates, even know they did start making defenders, they got to a point where they sorta just gave up on that endeavor completely. This may simple have been the fact that as it took them so much time to build up a fleet to to kill the pirates, there moral had gotten to low and they were like "oh im going to stop going for planets i have other things to worry about!". In fact at the start of the game if you clear the FOW, you can basically tell what order the power of each faction will be later by comparing how many local pirates near habitability planets are close to the AI home world.

There are so many posts already about the problems of Approval so I wont go to much into it, but im guessing once its fixed the AI will naturally get alot better. they need to stop building so many farms so early making there approval go into the red, this in turn will not give them all the penalties to production/research and such. I was watching there shipyard early on trying to build colony ships that would take them over 140 turns :/. And then hopefully once this is fixed it will at least give the AI more of a chance to succeed.

I've come to conclusion that pirates should be rebalanced too. Maybe give them a later start tied up to some check-event like "races have colonized 20% of planets" or "someone invented galactic warfare tech". First check will allow the players to have the chance to grab some land before pirate shipyards start to appear and the second will let them have a fighting chance by been able of producing armed ships.

Yeah that idea is nice but only works if the pirates will stay in their area. What would you do if a pirate base spawns not far off you homeworld and their fleets will seige you planet not even letting you to lift your head? Still the idea is nice. At any rate some checks for the pirates and the ai REALLY need to be done. I like it more the way it was done in civilization series.

Go troll somewhere else.

Well that could be working. Now let's wait and see for someone in the devs do something about all those glitches.

I noticed clusters create some funky staring locations. Using rare habitable planets has odd situations where they is a small cluster could have maybe 3 planets including the starting one, then a huge space where you have to build star bases and focus on range to get out. By then most of the other planets are taken.

I have seen this happen to the AI and human players. One game the Krynn wren't discovered for well over 100 turns because I had to bud two star bases with extended range to reach the last group of 6-7 stars. The poor Krynn were stuck there as there was only their starting system, companion, one other habitable and one extreme. The were waaaaaaaaaaaaay behind everyone in tech, etc.

I have been playing around with creating maps and removing fog to see how the settings are working. It seems there is no correlation of faction placement with number of habitable planets in an area. By that I mean 3 factions could be based around 6-8 planets while another has 6+ to themselves. Some get stuck in pockets of nothing.

So in short, IMO the map generator could use a little love when using rare settings. Also the AI needs to realize it is "stuck" and work on building starbases for range and techs to extend ship range instead of worrying about mining and such.

After personal experience, I second Osbot's recommendations.

In my experience, they do colonize, but not enough. I think the AI has a long way to go in terms of how it colonizes and builds before it can keep up with a human player. None of this should be out of reach, the AI simply needs to specialize planets and utilize adjacencies better. I'm sure Stardock is hard at work on the AI, so I think there's a good chance they will get it sorted out eventually. Looking forward to starting a new game with the 1.01 patch to see how things are coming along.

I've basically figured out what the problem is.

It's primarily 2 issues. The issue we've covered already, regarding simply unfortunate map placement. The AI often has nowhere to expand to and by the time it can it's taken by someone else.

In regards to the second issue, I'll direct you to the Krynn, everyones favorite monster AI. Why? Morale. The AI is currently experiencing issues managing morale. A bug with the promethion pleasure park (it was giving 6 wealth instead of 6 morale) was compounding this problem. Even fixing that mixup, the AI still struggles with morale.

To test this, I made a mod that gave the AI a +4 bonus to morale on challenging difficulty, this is the first difficulty level where the AI gets bonus'. The difference? Enormous. The entire dynamic of the age of exploration changes. You are probably intimately familiar with the AI sending constructors across the galaxy to steal your resources. This behavior stops. Why? The AI was doing this because it wasn't willing to colonize further due to morale issues. Now with a +4 bonus the AI's morale problems are more reasonably managed and they spam colonizers.

There is a mod floating around in the mod section from someone who made a similar change which boosted AI morale. Until SD works out AI morale management, that is going to be the best fix.

Trust me it makes an enormous difference and the morale boost isn't completely crazy. Most players I am sure are rushing that +4 bonus in the second tier of research as it is for that enormous leg up.

That is what I noticed as well, but thanks for bringing it up. Even with a spiral, my bud and I were on the same spiral arm. However, I have mostly 10+ planets and he had 8- and fewer and was stuck on the spiral tip. Really, I while better than most, scattered over spiral for now. I mean, I like the challenge in SP, but MP it takes away from what I have accomplished if other players are stuck in a worse position.