From the introduction: Solaris: The Reaches provides new locations, 'Mech arenas, Archetypes, BattleMechs and supplemental rules for MechWarrior campaigns set on Solaris VII, which was described and mapped in the boxed game Solaris VII The Game World. All these items can be easily modified for MechWarrior campaigns set in other locales as well. This product is designed for use with MechWarrior, Second Edition, Solaris VII, and Battletech rules.