Simulation hypothesis

The Simulation hypothesis is a proposition that what we perceive to be physical reality, including all observable, measurable events (potentially to the quantum scale), are purely virtual in nature, a form of hyperreality, being the artificial product of a simulator rather than being the real in and of itself. The nature of the simulator is unknown, but is often presumed to be computational in nature, the supposition being that it may operate similarly to how a computer may be used to generate simulated realities, as in the form of video games.

The hypothesis is sometimes referenced in relation to the Retcon (or Mandela) effect as an explanatory mechanism (as opposed to assuming paramnesia).