The word "virtual" is often used as a prefix, but rarely defined itself.
Wikipedia derives virtuality from [[Virtual Reality]], as "*Virtuality is the quality of having the attributes of something without sharing its (real or imagined) physical form.*"
## In Philosophy
In philosophy [Gilles Deleuze](https://en.wikipedia.org/wiki/Gilles_Deleuze) used the term virtual to refer to an aspect of reality that is ideal, but nonetheless real.
Another meaning was derived from common usage in 2004 by Denis Berthier, based on uses in science, technology, and etymology: *At the same ontological level as "the possible" (i.e. ideally-possible) abstractions, representations, or imagined "fictions", the actually-real "material", or the actually-possible "probable", the "virtual" is "ideal-real"*.
## Richard Bartle
In his book "Designing Virtual Worlds", Richard Bartle described virtuality as:
* **Real**: That which is
* **Imaginary**: That which isn't
* **Virtual**: That which isn't, having the form or effect of that which is
This is a very good simplification of the philosophical approaches, making it simple to understand and inclusive enough for the current broad usage.
## Mixed Reality
[[Mixed Reality]] describes a spectrum (also known as the reality-virtuality continuum) from reality (no augmentation) to full virtuality (replacing reality with virtuality).
## Effects of creating virtuality
As for example [[Virtual Worlds]] create entire systems and environments in virtuality, it turns out that this does not "add some virtual aspects to reality", but instead "adds all of reality to the virtuality." People will bring all their human and cultural biases, assumptions, prejudices and even social systems along for the ride, immediately turning the non-real system into a real one.
> “In a lot of ways virtual worlds are just machines replicating and underlining the necessity for real-world concepts and structures like constitutions, laws, governments, police forces and so on.” — Raph Koster
As a result, there is no meaningful way to disambiguate reality from virtuality, once they have been entered. See [[Virtual Worlds#It's all the same]]. And arguably, even once they are designed. See [[Magic Circle]].