The first edition of this encyclopaedia was published in 1979. This edition, now available in paperback, is intended to be more than a simple updating. The world of science fiction in the 1990s is much more complex than it was in the 1970s. The advent of game worlds, shared worlds, graphic novels, film and television spin-offs, technothrillers, sf horror and others has meant that the book has been expanded dramatically to cope with the complexities and changes in the genre. It contains well over 4300 entries - 1500 more than the original - and, at 1.3 million words, is over half a million words longer than the first edition.