A colony (known as a base until the Avalon Hill edition) is a group of one player's ships on a single planet. A colony on a player's own planet is called a home colony, and a colony on another player's planet is called a foreign colony. Each player starts with five home colonies (one on each of his or her home planets). The game is won once one or more players gain five (four if playing a short game) foreign colonies. If a player has only two or fewer home colonies (one or fewer if playing a short game), he or she cannot use his or her alien power until he or she regains enough home colonies.