Race for the galaxy xeno invasion an expansion for the rftg base game that comprises the third story arc in the game series depicts the galaxy as being under attack by waves of violently xenophobic aliens dubbed the xenos xi adds xeno military worlds worlds conquered and occupied by them specific military vs xenos and a new keyword anti xeno to provide a good proportion of new xeno worlds keyword and powers xi is not compatible with the other expansion story arcs xeno invasion is aimed at