Shattered Fortress is one of two sourcebooks/scenario books that details the last years of the Dark Age era (from 3146 to 3150). The included events are the invasion the Republic of the Sphere's Fortress Walls' into Prefecture X and highlights other major events occurring across the Inner Sphere.
Included among its rules are other gaming enhancements allowing play in Total Warfare Game Rules, A Time of War RPG, and Alpha Strike. Featured in the back of this book are mini-campaigns for various events during this era using the Chaos Campaign Rules/Warchest Point System. In this book, it discusses the possible methods that made the Fortress Walls and HPG Blackout possible.