Recent work has shown that, under certain assumptions, zero-shot reinforcement learning (RL) methods can generalise to any unseen task in an environment after reward-free pre-training. Access to Markov states is one such assumption, yet, in many real-world applications, the Markov state is only partially observable. Here, we explore how the performance of standard zero-shot RL methods degrades when subjected to partially observability, and show that, as in single-task RL, memory-based architectures are an effective remedy. We evaluate our memory-based zero-shot RL methods in domains where the states, rewards and a change in dynamics are partially observed, and show improved performance over memory-free baselines. Our code is open-sourced via: https://enjeeneer.io/projects/bfms-with-memory/.
@article{arxiv.2506.15446,
title = {Zero-Shot Reinforcement Learning Under Partial Observability},
author = {Scott Jeen and Tom Bewley and Jonathan M. Cullen},
journal= {arXiv preprint arXiv:2506.15446},
year = {2025}
}