The original Eon Productions edition of Cosmic Encounter was released in 1977. It included 15 aliens and supported up to four players.
Aliens
Fifteen aliens were included with this edition:
Amoeba • Chronos • Clone • Empath • Laser • Macron • Mind • Mutant • Oracle • Philanthropist • Trader • Virus • Void • Vulch • Zombie
Expansions
A total of nine expansion sets were released, bringing the total number of aliens to 75 and players to six:
- Expansion 1 (1977): 10 new aliens and orange (silver in early print runs) components for a 5th player
- Expansion 2 (1977): 10 new aliens and purple (gold in early print runs) components for a 6th player
- Expansion 3 (1978): 15 new aliens and new cards for the deck
- Expansion 4 (1979): Flares for all aliens from the base game and expansions 1-3
- Expansion 5 (1980): Moons
- Expansion 6 (1981): Lucre and 10 new aliens, many of which made use of Lucre
- Expansion 7 (1981): 14 new aliens
- Expansion 8 (1982): Flares for all aliens from Expansion 6, Expansion 7 and the upcoming Expansion 9, and new cards for the deck, including the new Kickers
- Expansion 9 (1983): 1 new alien and stickers for two new gameplay variants