Cosmic Encounter is a board game in which three or more players compete and cooperate in order to conquer enemy planets and spread their influence across the galaxy. This is done by managing one's hand and forces of ships, playing cards at the right time, and skillfully forming alliances with the other players. Each player plays as an alien race with its own unique power, allowing players to skew certain rules of the game to their advantage. Once one or more players have established five colonies on opposing planets, they win the game.