Validate the Dream Before You Trust Its Verdict: Admissibility for World-Model Simulators

Understand

Across robotics, World Models (WMs) are increasingly used to evaluate action policies by simulating the consequences of actions in an imagined world, and returning a success or safety verdict.

• Yet a verdict is only as trustworthy as the WM that produced it, and the WM itself needs to be certified.
• In video-generation WMs, fidelity metrics such as Fr\'echet Video Distance (FVD) reward visual realism, but ignore whether the world responds correctly to the policy's actions, including those unseen in training.
• Classical simulation-based validation assumes a trusted simulator evaluating an untrusted policy, whereas generative WMs are themselves unverified learned artifacts.