  We investigate competitive co-evolution of unit micromanagement in real-time
strategy games. Although good long-term macro-strategy and good short-term unit
micromanagement both impact real-time strategy games performance, this paper
focuses on generating quality micro. Better micro, for example, can help
players win skirmishes and battles even when outnumbered. Prior work has shown
that we can evolve micro to beat a given opponent. We remove the need for a
good opponent to evolve against by using competitive co-evolution to evolve
high-quality micro for both sides from scratch. We first co-evolve micro to
control a group of ranged units versus a group of melee units. We then move to
co-evolve micro for a group of ranged and melee units versus a group of ranged
and melee units. Results show that competitive co-evolution produces good
quality micro and when combined with the well-known techniques of fitness
sharing, shared sampling, and a hall of fame takes less time to produce better
quality micro than simple co-evolution. We believe these results indicate the
viability of co-evolutionary approaches for generating good unit
micro-management.
