The Star Wars Rules Companion (1989)

From the back of the book:
Expand your Star Wars campaign with the new roleplaying game supplement! The Star Wars Rules Companion incorporates the important changes and clarifications from The Star Wars Rules Upgrade, as well as new options suggested by you, the players, to create an even more exciting roleplaying experience.

80 page booklet includes:
-Advanced rules for the force
-Revised and expanded rules for personal combat, movement, damage, and healing.
-New instructions for creating droids
-New rules for staging capital ship battles
-A new system for converting ship from the roleplaying game to Star Warriors starfighter combat boardgame.
-Full color pictures from the movies plus art and photographs from the Lucasfilm archives.