Ulbasca is one of the two great ocean worlds in the Cularin system. Similar to the other water world of the system, planet Cularin, Ulbasca is close to the system's suns, producing very warm summers and mild winters. During the winter months, the oceans in the northern and southern poles freeze over, creating ice fields similar to those found on the planet Cularin.

The major landmass of Ulbasca is situated near the moon's equator. Originally formed from underwater volcanic eruptions, these vast plateaus provide an excellent place for fields to grow and also create a prime location for urban development. The large grasslands also led to the development of a variety of animal species, some of which have the ability to live both above and below the water that dominates the surface.

Apart from the grassland continent, Ulbasca also has a large desert island that is located in the northern hemisphere. It is not well understood how exactly the desert came to be, but it is extremely hot. Despite the temperatures, the first major city on the planet was constructed on its arid dunes.

While humanoid species never naturally evolved on Ulbasca, the geography of the moon made it a popular place for colonization and development. During the many wars for control of the system, it was mostly ignored, with the conflicts focused more on the material-rich planets Morjakar, Dorumaa, and Almas -- the key prizes of the system. Ulbasca, in contrast, provided a promise of peace to sentients, whose homes were destroyed, and many settled in the large cities that were developing on the largest continent. United in determination, the mix of refugees and colonists created a very diverse culture, and the designs of the cities reflect it. Built by sentients of many different backgrounds and races, the cities were molded into a display of their lives and lifestyles. The cities that cover Ulbasca's surfaces have some of the most interesting architecture in the galaxy.

While most of the cultures on Ulbasca are quite diverse, the population overall is dominated by aquatic races, who can take advantage of the moon's large oceans.