Immersive technologies such as augmented reality, virtual reality, and mixed reality are finally taking off. As these technologies become more widespread, concerns will likely develop about their disruptive social and economic effects. This paper addresses such policy concerns and contrasts two different visions for governing immersive tech going forward. The paper makes the case for permissionless innovation, or the general freedom to innovate without prior constraint, as the optimal policy default to maximize the benefits associated with immersive technologies. The alternative vision — the so-called precautionary principle — would be an inappropriate policy default because it would greatly limit the potential for beneficial applications and uses of these new technologies to emerge rapidly. Public policy for immersive technology should not be based on hypothetical worst-case scenarios. Rather, policymakers should wait to see which concerns or harms emerge and then devise ex post solutions as needed.