Galaxy Guide 4: Alien Races

The initial version of Galaxy Guide 4: Alien Races, a supplement for Star Wars: The Roleplaying Game, was authored by Troy Denning and released by West End Games in 1989. A second edition offering a revised version was then issued in 1994.

From an in-universe standpoint, the book is presented as containing selections from the Catalog of Intelligent Life in the Galaxy. This catalog was compiled by Obo Rin, an Imperial sentientologist tasked by Darth Vader with documenting the various intelligent species inhabiting the galaxy. The introduction includes Imperial dispatches that offer an in-universe perspective on the creation of the Catalog.

While numerous species featured in the original trilogy are included, some were specifically created for the game. Moreover, the background details of several alien races that had appeared on screen were also conceived for the game. Many of these newly introduced species and background elements were subsequently incorporated into later works within the Expanded Universe with minimal alterations. However, certain retcons are required to align Galaxy Guide 4 with the prequel-era Expanded Universe. The most prevalent retcons involve species initially described as having their first encounter with the Galactic Empire, but later depicted as having prior interactions with the Galactic Republic. Given that the text portrays Obo Rin as a source with an Imperial leaning, these retcons typically attribute any inaccuracies to intentional Imperial propaganda and disinformation.