Quantum reality

From Memory Alpha, the free Star Trek reference.

A quantum reality is a common expression used to describe the speculative existence in quantum physics of a "level III multiverse". In very basic terms the concept imagines that for every possible state of existence at any given point in time there exists a reality which encompasses that state of existence.

For example, when a six-sided die is rolled there are six possible outcomes of the roll. In alternate quantum realities each of these outcomes exists and the perceived existence of a single state is not due to a fixed reality, but a fixed point of perception from which the other outcomes are not observable.

In 2370, Worf experienced several different quantum realities as a result of passing through a quantum fissure while returning from the bat'leth tournament on Forcas III. (TNG: "Parallels")