Abstract: The metaverse is the expanded world in which the virtual world interacts with the real world, and the ontological tenet of the metaverse is the principle of priority of the real world, and its metaphysical basis is the requirement of the transcendental self-uniqueness. What derived from this are the basic principles of metaversal ethics, namely the principle of harmlessness of the virtual world, the principle of voluntariness of the virtual world, the principle of distinguishability of the virtual world, and the principle of prohibition of duplicating human beings. The concept of “expanded reality” was first explicitly put forward by Professor Zhai Zhenming, but he adheres to the principle of equality between virtual and real worlds, and proposes “world-making ethics”. On the one hand, he advocates the transcendentality and uniqueness of the ontological self, but on the other hand, he equates the real world that can better embody this uniqueness with the virtual world that cannot embody this uniqueness, which leads to a theoretical inconsistency and puts his world-making ethics in a dilemma.

Key Words: Metaverse; Virtual reality; Expanded reality; Uniqueness of self; Principle of priority of the real world