🚀 go-pugleaf

Back a couple of years ago there was a great deal of discussion on Usenet 
with regards to the GalCiv I AI.  Most people thought it was pretty good but 
others felt the military tactics were bad.  That while the AI provided a 
challenge, it mostly was able to do so because it was more effective at 
managing its economy/industry than the typical human and thus could 
essentially "win" through brute force.

In general, my view was that the AI worked pretty well but militarily was 
disappointed. The main issue was its lack of coordination in projecting 
military power into a given quadrant.  The result was hat looked like the 
age-old "Death train" (That's where units uselessly throw themselves at a 
wall dying with no purpose). There simply wasn't enough analysis on putting 
units together and using them effectivley.

A lot of this came down to being restricted to CPU light algorithms.  GalCiv 
I was a sprite-based game -- no hardware acceleration.  So the graphics were 
CPU bound.  Even though the AI is, and continues to be, multithreaded, there 
are still very real limits on how much time can be spent generating 
multi-turn strategies.  GalCiv II, however, is 3D-accelerated which has 
freed up the CPU a great deal.  This has allowed for greatly expanded 
algorithms during military endeavors without raising the hardware 
requirements (in fact, on the typical PC, GalCiv II will run better than 
GalCiv I did ironically despite immense graphics improvements and 3D 
engine).

A lot -- A LOT -- of work has been going into the AI of Galactic 
Civilizations II in order to not just make it "challenging" but to make it 
play intelligently.  There were significant chunks of the GalCiv I AI that 
were scripted.  That is, the AI is programmed to do certain things due to 
play-testing over and over.  This time around, we're trying our best to make 
the AI build strategies based on analysis and not rely on scripts.

The improvements in the AI have led to a lot of changes, probably the 
biggest one being the elimination of the infamous "The AI knows where the 
good planets are" issue that GalCiv from the OS/2 days on up to the 2003 
release of GalCiv.  GalCiv II's AI has to build scouts and look for good 
planets just like everyone else.

To get an idea of what is involved in debugging such an AI, I chronicled one 
such game.  Mind you, we're now doing several of these types of games each 
day to tune the AI, to find flaws, etc.  The idea being that when the game's 
released, the difficulty levels will determine how smartly the AI plays 
rather than age old "Here's some money (or less of)" way that strategy games 
have used as a crutch.

Anyway, here's the URL to the AI debugging session entitled "Human/Drengin 
wars".  I through in flavor text as well to make it more interesting to 
read. ;)

http://www.galciv2.com/Journals.aspx?AID=98513

Brad
--
Brad Wardell
Project Manager: Galactic Civilizations II (www.galciv2.com)
Stardock - http://www.stardock.com