Evolutionary Multi-objective Optimization of Real-Time Strategy Micro

TL;DR

This paper presents an evolutionary multi-objective optimization method to generate diverse and high-quality micro tactics for mixed-unit groups in real-time strategy games, enabling better strategic trade-offs.

Contribution

It extends prior work by optimizing micro for mixed ranged and melee units using influence maps and potential fields, producing a Pareto front of tactical options.

Findings

Multi-objective approach yields diverse micro strategies

Pareto front includes tactics for different strategic trade-offs

Potential fields effectively represent spatial and combat information

Abstract

We investigate an evolutionary multi-objective approach to good micro for real-time strategy games. Good micro helps a player win skirmishes and is one of the keys to developing better real-time strategy game play. In prior work, the same multi-objective approach of maximizing damage done while minimizing damage received was used to evolve micro for a group of ranged units versus a group of melee units. We extend this work to consider groups composed from two types of units. Specifically, this paper uses evolutionary multi-objective optimization to generate micro for one group composed from both ranged and melee units versus another group of ranged and melee units. Our micro behavior representation uses influence maps to represent enemy spatial information and potential fields generated from distance, health, and weapons cool down to guide unit movement. Experimental results indicate that our multi-objective approach leads to a Pareto front of diverse high-quality micro encapsulating multiple possible tactics. This range of micro provided by the Pareto front enables a human or AI player to trade-off among short term tactics that better suit the player's longer term strategy - for example, choosing to minimize friendly unit damage at the cost of only lightly damaging the enemy versus maximizing damage to the enemy units at the cost of increased damage to friendly units. We believe that our results indicate the usefulness of potential fields as a representation, and of evolutionary multi-objective optimization as an approach, for generating good micro.