Lu'umism is the main religion of the Quil people (a general term for the 4 tribes). It is the exclusive worship of the personification of the Moon, otherwise known as Lu'um. It also includes the worship of the beings who are considered less than Lu'um, such as:
- Un, the universe and mother of Lu'um and Stel,
- Aqui, the god of water and adorer of Lu'um,
- Sto, the god of rain and storms,
- and Oc, the god of animals
Lu'um herself is considered to be a kind and gentle ruler who loves every single one of her subjects, and only punishes when those subjects have commited a great sin. Those who follow Lu'um to the best of their ability and worship her constantly get the ultimate gift of becoming a star, eternally shining along with Lu'um.
The main idea of Lu'umism is that Lu'um, the ruler of all that is divine, created the world and all that is in it. From the world sprung the two gods Terr (land) and Aqui (sea). Humanity as it is known came from Terr and Aqui, and is benevolently ruled over by Lu'um, who shines her loving light on them every night.
Lu'umism can be directly connected to the Aust'a tribe's discovery of the Moon pushing and pulling the ocean. The complete and utter control of their food and life source, the ocean, by the Moon, made the Quil people realize how powerful the Moon was, and how Lu'um ruled over all.