This is non-negotiable. It contains the D20-based mechanics, the 8 character classes (Mystic, Soldier, Hacker, etc.), and the bestiary (Cratures). The "top" version includes the official errata, which fixes the "Flamethrower" wording error from the first print run.
* Joseph A. McCullough. * Helge C. Balzer, Sam Lamont, Paolo Puggioni, Michele Giorgi. * 176. * ISBN. 9781472837516. * 29.51 MB. * DriveThruRPG Science Fiction Wargames in the Ravaged Galaxy - YUMPU stargrave pdfcoffee top
While PDFCoffee hosts user-uploaded files, the most stable and legal ways to access content are through official channels: Osprey Publishing: This is non-negotiable