The agent performs well in simulation.
When deployed in the real world, it makes strange decisions.
The physics is slightly different.
Small changes lead to big failures.
Why does my reinforcement learning agent behave unpredictably in real environments?
Nishant MishraBegginer
This happens because simulations never perfectly match reality. The model learns simulation-specific dynamics that do not transfer.
This is known as the sim-to-real gap. Even tiny differences in friction, timing, or noise can break learned policies.
Domain randomization and real-world fine-tuning help close this gap.
Common mistakes:
Overfitting to simulation
No noise injection
No real-world adaptation
The practical takeaway is that real environments require real data.