Simulation hypothesis

The Simulation Hypothesis is a philosophical idea proposing that what somebody sees as "reality" may actually be a simulation, and that this person would not likely be aware of this.

There is also a very old and enduring thought experiment put forward by philosophers that any sufficiently advanced civilization would eventually attempt to create a simulation universe, if such a thing were possible. Since there would be many more simulations (possibly including simulations within simulations) than real universes, it is likely that our own world is artificial.