Year: 2025
Type: article
Abstract: Open-world games such as Minecraft pose significant challenges for reinforcement learning (RL) systems due to their long-horizon objectives, sparse rewards, and requirement for compositional skill learning. This study investigates how a Hierarchical Deep Reinforcement Learning (HDRL) approach can improve agent performance and sample efficiency in such complex environments. We develop a hierarchical agent composed of three interconnected levels: (i) a high-level planner responsible for decomposing tasks into subtasks using the options framework for temporal abstraction, (ii) mid-level controllers that manage reusable subtasks such as resource gathering, crafting, and smelting, and (iii) a low-level visuomotor policy that interacts with the environment through human-like keyboard and mouse inputs. The agents learning pipeline integrates pretraining from human demonstration datasets (MineRL) and large-scale video pretraining (VPT) to establish behavioural priors before reinforcement learning fine-tuning. This design leverages modern hierarchical algorithms such as Option-Critic, FeUdal Networks (FuN), HIRO, and Hierarchical Actor-Critic (HAC), enabling the agent to operate across multiple temporal scales. Evaluation is conducted using Obtain Diamond-style benchmarks and BASALT “reward-free” tasks to measure generalization and human alignment. Ablation studies assess the effect of each hierarchical layer, the inclusion of demonstrations, and large-scale video-based priors on overall performance. Results indicate that HDRL substantially enhances task completion rates and sample efficiency compared to monolithic RL agents, particularly in long horizon and reward-sparse scenarios. This research was conducted to address the limitations of existing RL systems in complex, open-ended worlds and to explore how hierarchical structures can bridge the gap between low-level control and high level planning. The findings demonstrate that hierarchical reinforcement learning provides a scalable and interpretable framework for developing agents capable of long-term reasoning and adaptive skill composition. The proposed model advances the state of the art in game-based AI, offering insights applicable to both Minecraft research and broader domains involving open ended task learning and autonomous decision-making.
Author: Arjun Panwar
Institution: Virginia Tech
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4415584345