In the first kind, entities are given a goal, and they find a solution via genetic algorithm. In the second kind, entities are given space to wander around freely, and evolve organically. In the third kind, entities are not explicitly coded, and instead we see life-like patterns emerge from the rules. Capitalism vs socialism? One thing I learned from this post was about the Millenium Challenge 2002, which was a war game exercise conducted by the US military.