This 6-card expansion adds 6 alien races to the game, only 2 of which are used in a given game. Players, in addition to normal actions, may attempt to ally with, or vanquish, the alien races. Allied aliens give you an ongoing effect that modifies other actions in the game, while vanquishing the aliens prevents allied effects and gains you victory points. These alien homeworld cards are placed in the center of the table and represent the aliens that are currently in place on specific planets. If a player tried to inhabit one of those locations, they must either align with the alien and take a special power for the rest of the game -OR- vanquish the alien to gain additional stars.