Writing science fiction and fantasy means world building. Maps, political systems, cultural details, biology, psychology, sociology, magic and technology are just a few examples of what the writer must manipulate. Certain aspects may be the same as our own world or differ in varying degrees. All the little details make a world rich and alluring, such as in Sir Terry Pratchett's Discworld series. It can also create a sense of alien 'otherness', such as in C.J. Cherryh's Fo