Minigrid & Miniworld: Modular & Customizable Reinforcement Learning Environments for Goal-Oriented Tasks
Maxime Chevalier-Boisvert, Bolun Dai, Mark Towers, Rodrigo de Lazcano, Lucas Willems, Salem Lahlou, Suman Pal, Pablo Samuel Castro, Jordan Terry
TL;DR
The paper presents Minigrid and Miniworld as lightweight, modular RL environments for goal-oriented tasks, emphasizing a minimal yet extensible API and ease of use. It details the design philosophy, environment specifications, and the unified API that enables cross-environment transfer learning between 2D and 3D observation spaces, demonstrated through PPO-based transfers and human-subject experiments. Case studies illustrate practical benefits and provide implementation guidance, wrappers, and code-effort estimates, highlighting the workflow's reproducibility. The work positions these libraries as accessible platforms that facilitate rapid research while acknowledging limitations like simple environment types and Python performance, with future directions including human-in-the-loop decision-making.
Abstract
We present the Minigrid and Miniworld libraries which provide a suite of goal-oriented 2D and 3D environments. The libraries were explicitly created with a minimalistic design paradigm to allow users to rapidly develop new environments for a wide range of research-specific needs. As a result, both have received widescale adoption by the RL community, facilitating research in a wide range of areas. In this paper, we outline the design philosophy, environment details, and their world generation API. We also showcase the additional capabilities brought by the unified API between Minigrid and Miniworld through case studies on transfer learning (for both RL agents and humans) between the different observation spaces. The source code of Minigrid and Miniworld can be found at https://github.com/Farama-Foundation/{Minigrid, Miniworld} along with their documentation at https://{minigrid, miniworld}.farama.org/.
