This book gives you information on the early conflicts and state of the Inner Sphere during the early Dark Age era of BattleTech (3131-3135), including notable personalities of splinter groups during that period and a history and timeline of events between 3132 and 3134, as well as two new 'Mechs and a new vehicle. All of this information included in the book is done well for the size of the book.

However, I did find one key problem with the portion regarding making characters in A Time of War. All of the affiliations require Era Report 3145 to create a character (unless your character somehow happens to be from the Deep Periphery or Homeworld Clans). Having purchased this book for that specific reason (and not owning Era Report 3145 or Field Manual 3085), I am very disappointed in that part of the book. The rest of the information about actually role-playing during this era (once you have a character) is done fairly well.