The StarCraft Multi-Agent Challenges+ : Learning of Multi-Stage Tasks and Environmental Factors without Precise Reward Functions

TL;DR

This paper introduces the SMAC+ benchmark for multi-agent reinforcement learning, emphasizing multi-stage tasks and environmental factors without explicit rewards, highlighting challenges and potential directions for future research.

Contribution

The paper presents SMAC+ as a new benchmark that extends previous challenges by focusing on implicit multi-stage tasks and environmental factors in MARL.

Findings

Recent MARL approaches perform well in familiar settings but struggle in offensive scenarios.

Enhanced exploration improves performance but does not solve all challenges.

SMAC+ reveals limitations of current algorithms and guides future research directions.

Abstract

In this paper, we propose a novel benchmark called the StarCraft Multi-Agent Challenges+, where agents learn to perform multi-stage tasks and to use environmental factors without precise reward functions. The previous challenges (SMAC) recognized as a standard benchmark of Multi-Agent Reinforcement Learning are mainly concerned with ensuring that all agents cooperatively eliminate approaching adversaries only through fine manipulation with obvious reward functions. This challenge, on the other hand, is interested in the exploration capability of MARL algorithms to efficiently learn implicit multi-stage tasks and environmental factors as well as micro-control. This study covers both offensive and defensive scenarios. In the offensive scenarios, agents must learn to first find opponents and then eliminate them. The defensive scenarios require agents to use topographic features. For example, agents need to position themselves behind protective structures to make it harder for enemies to attack. We investigate MARL algorithms under SMAC+ and observe that recent approaches work well in similar settings to the previous challenges, but misbehave in offensive scenarios. Additionally, we observe that an enhanced exploration approach has a positive effect on performance but is not able to completely solve all scenarios. This study proposes new directions for future research.