For millennia humanity has traveled the stars, building empires that span hundreds of light-years. Those empires are home to a myriad of complex civilizations. This source book takes an in-depth look at the cultures and societies of the powers of the BattleTech® universe. Take a candid look at what life is like in the Inner Sphere, whether you're a Capellan who just gained citizenship or a Federated Suns student attempting to gain entrance to the prestigious New Avalon Institute of Science. The Inner Sphere sourcebook provides information on the five great Houses -- Kurita, Davion, Liao, Marik, Steiner -- as well as the lesser powers of the Periphery. The Inner Sphere also offers general histories of each society, comprehensive maps and a section detailing ten key worlds of the Inner Sphere.