New Century Zero takes place a long time after the events of Zoids: Chaotic Century. Zoids are no longer used for warfare; instead the combative natures of both Zoids and humans are focused and contained by a series of battle-competitions and tournaments, run by the Zoid Battle Commission. The Zoid Battle Commission seems to be a significant power on Planet Zi, fielding a considerable arsenal of armed Zoids, orbital platforms serviced by their own launch facilities as well as orbital based weapons systems. It is not made clear in the series if the Helic Republic and Guylos Empire still exist, although the final battle upon the rusted Ultrasaurus, hinted to be same one in Zoids: Chaotic Century, could suggest neither were left and people had free rein to battle in old battlefields.