The first Eon edition was released in 1977. It allowed up to four players and included fifteen alien powers. Over the next five years, Eon released nine expansions, adding sixty more alien powers, components for a fifth and sixth player, and several new types of pieces, including "Flare" cards, money (Lucre), Moons, and special power planet systems. The artwork on these early editions included images painted by Dean Morrissey. Eon published three versions of the base game, differing only in box size and cover art.