This category has to do with immersive, graphical, persistent state environment, virtual worlds -- like a WideOpenSandbox {{MMORPG}} that is ''all'' sandbox. These worlds could someday become TheMetaverse, while some argue that they already are. Their counterpart, OnlineGames, may use the same UsefulNotes/PhysicsEngine and physical hardware, but are centered on a particular game title, and unlike the often long-lived Virtual Worlds, are likely to become an OrphanedSeries. The line between Online Games and Virtual Worlds is blurry, as extensive [[GameMod modification]] can turn one into the other; such as a private server running ''VideoGame/WorldOfWarcraft'' without mobs of monsters, or a ''VideoGame/SecondLife'' island that features a user-scripted paintball game that is only playable in a limited area.

For in-universe virtual worlds, see LotusEaterMachine, {{Cyberspace}} and InsideAComputerSystem. Compare ImmersiveSim.

* ''Active Worlds''
* ''Croquet''
* ''VideoGame/{{Furcadia}}''
* ''Open Simulator''
* ''VideoGame/SecondLife''
* ''Franchise/TheSims''