Richard Bartle
Bartle received a Ph.D. in artificial intelligence from the University of Essex, which is where he created MUD along with Roy Trubshaw, in 1978.
He lectured at Essex until 1987, when he left to work full time on MUD (known as MUD2 in its present version). Recently he has returned to the university as a part-time professor and principal teaching fellow in the Department of Computing and Electronic Systems, supervising courses on computer game design as part of the department's degree course on computer game development.
In 2003, he wrote Designing Virtual Worlds, a book about the history, ethics, structure, and technology of massively multiplayer games.
Bartle is also a contributing editor to Terra Nova, a collaborative blog that deals with virtual world issues.
Bartle did research on player personality types in massively-multiplayer online games. In Bartle's analysis, players of massively multiplayer online games can be divided into four types: achievers, explorers, socializers and killers. This idea has been adapted into a popular online test generally referred to as the Bartle Test.[1] The test is very popular and scores are often exchanged on popular MMORPG forums, or networking sites.