"The first [advantage] was our optimization-based approach to the core design. The defensive towers and unit types in City Conquest were not based on arbitrary creative decisions: nearly all of the decisions around their functional aspects were guided by an explicit decision modeling process."

"The second advantage was Evolver, which we discussed in an earlier interview with AIGameDev.com. Evolver was an automated balancing tool based on coevolutionary genetic algorithms. Every night, it would run a huge number of simulated games between red and blue opponents, with each opponent evolving a "population" of scripts (each script being essentially a fixed build order of buildings within the game)."

The good stuff starts on page 2.