I think the true innovators in that realm are games like Ultima Online and Star Wars Galaxies, both of which were heavily influenced by Raph Koster, who came from a background of roleplaying in MUDs.
There have been lots of "sandbox" games before and after, but those two really captured the right balance between creating a rich world to explore and giving the player(s) the tools to shape it and create their own stories. They really understood the concept that "it takes a village" of different players and playstyles to form a dynamic community. I think they were really ahead of their time and hinted at what might be possible in terms of creating compelling alternate realities in VR.
There have been lots of "sandbox" games before and after, but those two really captured the right balance between creating a rich world to explore and giving the player(s) the tools to shape it and create their own stories. They really understood the concept that "it takes a village" of different players and playstyles to form a dynamic community. I think they were really ahead of their time and hinted at what might be possible in terms of creating compelling alternate realities in VR.