Verisimilitude

In a literary work, verisimilitude is likeness to the truth i.e. resemblance of a fictitious work to a real event even if it is a far-fetched one.

Verisimilitude ensures that even a fantasy must be rooted in reality, which means that events should be plausible to the extent that readers consider them credible enough to be able to relate them somehow to their experiences of real life
There are a vast amount of examples of verisimilitude
e.g:

  The world of Batman The Dark Knight series is a pure example of verisimilitude.