Galaxy Guide 4: Alien Races (Second Edition)

While many of these species did appear in the original trilogy, some were invented for the game. The background information for several of the alien races who had appeared on screen was also invented for the game. However, many of the new species and backgrounds were used in later works in the Expanded Universe with little modification. However, some retcons are needed to bring Galaxy Guide 4 in line with the prequel-era Expanded Universe. The most common retcons necessary are those where a species described as having its first contact with the Galactic Empire are shown in later works to have some contact with the Galactic Republic. Since Obo Rin is said in the text to be an unreliable source with an Imperial bias, these retcons are usually made by blaming inaccuracies on deliberate Imperial propaganda and misinformation.

The second edition, in addition to rewriting the game mechanics for the second edition rules, expanded and reorganized the description of the various alien species. The introductory matter was rewritten as well, with different Imperial communiqués. Accordingly, the second edition of Galaxy Guide 4 referred to the Catalog of Intelligent Life in the Galaxy, Revised Edition.