This Cosmic Encounter variant is a direct reversal of the standard game. Rather than attempting to gain five bases outside of his system and thus spread across the universe, each player is trying to rid his beloved system of encroaching races.
Game Preparation: Players set up by distributing ten of their tokens among any of their opposition's planets, with at least two tokens per system. After all players have distributed their ten tokens, each places his remaining ten on any planets he wishes in his home system.
The Play: The game is then carried out normally, with a simple change of the victory condition. The winner is the payer who first rids his system, including moons, of all other players' tokens. This is regardless of the number of external bases a player may have.
Do not use this variant with the Dictator, the Will, or other powers that ignore the destiny pile.
Variant by Jeffrey Field (Space Gamer 66)