While visiting Professor Rafkin in order to investigate the Orb of the Moons that was found, the orb itself created a warp gate that transports the Avatar to Eodon, a world featuring dinosaurs who live among several warring tribes. Now it's up to the Avatar to bring peace to these warring tribes.

Ultima: Kyouryuu Teikoku is a port of Worlds of Ultima: The Savage Empire. However, the game has been altered in some ways. The most glaring change is that this version eschews turn based combat in favor of a more action oriented combat system. The Avatar also travels alone instead of being in a party of adventurers. Other changes include there being a smaller amount of items to pick up and the day and night cycle being only cosmetic instead of affecting the schedules of the NPC's.