One of the most frustrating parts of the GalCiv AI for me has been the planetary improvements.  It is the single biggest piece of the code I didn't write and to be honest, my C++ skills are relatively basic. I'm an algorithm guy, not a particularly good coder. The result is, I've always had a hard time working on the improvement code because it's hard for me to understand (it was implemented as a quasi-SQL database as opposed to say a linked list or an array).

So anyway, while playing this weekend, I finally came to understand the single biggest problem with the computer AI with planetary improvements: It doesn't check to see if it is already building a super project or achievement on one of its other planets.

This is a pretty big deal because what will happen is that if it wants to build an economic capital, odds are, quite a few planets may have the same idea. But when the other planets try to put that into the queue, it gets rejected (without the AI knowing it).  As a result, during that entire time, the AI is building nothing.  So players would come across AI planets with hardly anything built.

Now, this doesn't stop the other pet peeve - the AI building stupid things on a planet (like 10 morale buildings or something).That, I still haven't figured out but I'm working on it.