This book is about design patterns and known consequences of those design patterns in virtual world design. In other words, it gathers together information on what has been done in the field in the past, and it also assesses the consequences and results of many of those choices. Much of the book is concerned with taxonomy, in that it attempts to classify and sort into tidy little bins many of the general design decisions made in the past. We should recognize from the outset that things are rarely so clear-cut that particular games or designs can be neatly classified—things are not commonly so black and white. But it is still of value to engage in this sort of pattern recognition, even if no single implementation fits the archetype that the pattern defines, because it allows us to intelligently discuss design elements within a context, with a commonly shared vocabulary, whilst well-informed as to the history of the field. The hope is that by thus classifying and identifying design patterns and history, the book can arrive at a partial grammar of the genre.

In the case of virtual spaces, the history worth examining is not that of virtual reality research (which has never had a significant actual virtual population of users) but rather, the history of muds and their ilk, the largely text-based games and social spaces that began to be actively played by college students on the Internet in the early 80’s. Fortunately, despite the lack of criticism, there’s a copious quantity of historical information available, dating back to the very origins of the genre.