PD One: Prime Directive Core Book 1993The original Prime Directive core rulebook, sometimes called PD1, let you roleplay in the Star Fleet Universe. Using its own game engine, you could be a member of a Prime Team, the elite of the Star Fleet Operations Corps. This core rulebook codified the many species found in the Star Fleet Universe, listed equipment which can be adapted to most gaming systems, has adventures to run, and includes the Black Eagles Prime Team stationed on the Saratoga.