  Multi-agent reinforcement learning (MARL) plays a pivotal role in tackling
real-world challenges. However, the seamless transition of trained policies
from simulations to real-world requires it to be robust to various
environmental uncertainties. Existing works focus on finding Nash Equilibrium
or the optimal policy under uncertainty in one environment variable (i.e.
action, state or reward). This is because a multi-agent system itself is highly
complex and unstationary. However, in real-world situation uncertainty can
occur in multiple environment variables simultaneously. This work is the first
to formulate the generalised problem of robustness to multi-modal environment
uncertainty in MARL. To this end, we propose a general robust training approach
for multi-modal uncertainty based on curriculum learning techniques. We handle
two distinct environmental uncertainty simultaneously and present extensive
results across both cooperative and competitive MARL environments,
demonstrating that our approach achieves state-of-the-art levels of robustness.

Machine Learning