The Gateworld of Rhihhi is world split between two different trees of life. One ecology is of terrestrial origin, while the competing ecology is of an alien nature. Across the planet organisms from both ecologies compete for resources. The biochemistries of these organisms are incompatible, disallowing stable food chains to be developed between the two diverse ecologies.

Three thousand years ago, as measured by a year on lost Tellus, populations of neohumans migrated through a collection of gates onto a region they called the Plain of Falling Stars. Here, they found terrestrial life had dominated over the alien organisms.  Most of the rest of the world is a wilderness of alien life.

These migrating populations founded fortified nation states that grew into vast enclosed urban areas. These huge nation cities became home to millions of neo-humans. Three thousand Tellusian years ago, when the nation cities were founded, there were seventeen cities. After centuries of wars and crisis, the number of nation cities eventually fell to eleven.

Beyond the Plain of Falling Stars, the neohumans discovered two other civilizations; the Sea Association, and the island nation of Pamelin. The Sea Association a society of five different marine lifeforms that appear to be sapient, but of the alien biology.. Contact between the nation cities of the Starry Plain and the Sea Association was infrequent, with communications often being misunderstood, leading to hostility between the two civilizations. This has lead to sea travel being highly restricted, as the Sea Association seeing human ships as intruders to their territorial waters.

 The island of Pamelin was settled by populations of ellyllon and urhumans some time within the last thousand tellusian years through a gate located far out to sea. Politically, Pamelin is affiliated with the Anku Republic on the world of Sacrisca. Contact between the Nation Cities and Pamelin are infrequent due to the hostility of the Sea Association to human ships. A trade route was forged a few centuries ago that crosses almost a thousand miles of wilderness, but travel is dangerous and sporadic.

The hostile nature of the world has led to most travel and trade from the nation cities to be directed through the gates to other worlds. There is little expansion beyond already settled regions.