The Earthdawn Companion is a rules expansion for the Earthdawn game system. The information in this book allows players and gamemasters to make their characters more powerful. This book picks up where the rulebook ended. The Companion expands the 13 Disciplines presented in the rulebook to 15th Circle, and provides talents and spells for those Circles. The Companion also provides rules for additional uses of thread magic in your Earthdawn game, and describes many new types of magical items.

Also included in this book are rules for playing questors, people who have devoted their lives to a single Passion, and Lightbearers, people dedicated to eradicating all traces of the Scourge and the Horrors from the world.

The Optional Rules section offers ways for players and gamemasters to tailor Earthdawn to better suit their style of play.