From the back of the book: They came from the Periphery in devastating war machines piloted by genetically engineered warriors. They are the Clans, descendants of the great Aleksandr Kerensky, the legendary general who led the remnants of the Star League army out of the Inner Sphere and away from the rising tide of war. Their very names strike fear in the hearts of their foes. Ghost Bear. Diamond Shark. Nova Cat. Smoke Jaguar. Steel Viper. Jade Falcon. Wolf. But who are these mysterious invaders? How have they changed from their cousins who remained behind in the Inner Sphere? In the tradition of the Clan Wolf and Jade Falcon sourcebooks, Invading Clans details the history, culture and military might of the remaining invading Clans. User comment: This book is a companion volume to the two more specific Clan volumes produced for the Wolf and Jade Falcon Clans, and details the other five Clans that invaded the Inner Sphere, to varying degrees of detail. Expanding on the background detail are details and in-game stats for 10 new BattleMechs, two for each of the Clans. These were later reproduced in the BattleTech: Technical Readout 3058, so if you own that sourcebook already you won't get any new equipment out of this one, but the background is useful when constructing games that feature the Clans, as protagonists or antagonists.