This was from the old GC2 manual. There was a better breakdown from Brad a looong while back somewhere IIRC, but I'm having trouble finding it... In short the AI performs more complicated tasks at higher difficulty settings. Also, worth of note: it does not cheat, (apart from economic bonuses?), it has to scout blindly for planets/resources, has to scout other AI and the human player's assets, etc. It does not "know" anything that a human player wouldn't know - which isn't to say that it isn't smarter than most players. heh
Fool
The AI's economy is run at 10% of normal, no higher level algorithms are enabled
Beginner
The AI's economy is run at 25% of normal, no higher level algorithms are enabled
Sub-Normal
The AI's economy is run at 50% of normal, no higher level algorithms are enabled
Normal
The AI's economy is run at 75% of normal, AI evaluates common human tactics
Bright
The AI's economy is run at 100% of normal, AI evaluates most known human tactics
Intelligent
The AI's economy is run at 100% of normal, AI expertly picks abilities and all known
human tactics are searched and countered
Genius
The AI's economy is run at 125% of normal, All AI algorithms in place (same as
above)
Incredible
The AI's economy is run at 200% of normal, All AI algorithms are in place
-tid242
-edit: oh, and an aside - the current AI in GC3 isn't as such, rather it's just a placeholder that wanders around and interacts with the player - the big focus right now is making sure all of the systems work properly before trying to write an AI that operates within said systems.