Originally the Master of Dungeons software were A.I. that ran live-action dungeons. The players could smash up sophisticated robots engineered for that one purpose and feel good, strong and heroic.

Until that fateful night, where an update to one of the Master of Dungeons A.I. pushed it over the threshold separating artificial intelligence from artificial sentience.

Several thousand years later, the Masters of Dungeons are a group of living, formerly artificial beings (mostly software, with a bit of magic mixed in) that still follow the basic purpose of that first Master of Dungeons: Entertainment.

Entertainment, almost exclusively, of themselves and each other. What's left of the human race occasionally gets thrown in for some additional fun.