Galaxy Guide 12: Aliens — Enemies and Allies is a supplement to Star Wars: The Roleplaying Game published by West End Games in 1995. It was written by several writers, each of whom wrote on one or more species. Much as in West End Games' earlier sourcebook, Galaxy Guide 4: Alien Races, some of the species detailed appeared in the original trilogy, while some were invented for the game. West End Games would follow Alien Races and Aliens — Enemies and Allies with a third book, Alien Encounters.