Prime Circle

Evidence suggests that every planetoid in 100 Worlds has (or at one time had) an ancient teleportation circle on it. Most believe they were built by the Ancients.
These ancient teleportation circles are know as Prime Circles
These sigil sequences may or may not be known on other planetoids. The sequences are written in ancient hieroglyphics which are difficult to translate. So the key sequences may be lost and forgotten or possibly never discovered. It is assumed the Aboleths of Yathanic have all of this lost knowledge at their disposal, but few are foolish enough to actively seek them out.
The gnomes of Erbasis have managed to secure their planets Prime Circle with a "Lock".