Fyr-ka'ar society evolved into a caste system early on and has rarely changed since. The founder of the country Azar named it after himself. He is the son of the Burning and the Fyr-ka'ar Manifest, and he grew to hate his mother for her refusal to choose him as her favorite, despite his being the most powerful of them. His jealousy and spite led him to kill any of his siblings he could not control through fear and injure and banish his own mother. He started the ruling family of Azar and

Their ruler is a maliko who is of the alriba caste. The maliko's family is rigidly alriba, and any born outside of this caste is disowned immediately. The caste system was imposed by a small group of very powerful fyr-ka'ar seeking to maintain control and power against internal rebellions against their cruel power. The caste system is viciously enforced, and the lower castes are in constant defiance. The enforcers are part of the warrior caste and are a special group called the ejmunafidhin (sing. ejmundafidh). In order to enforce breeding and supremacy, the alriba require a rigid set of gender roles: man, woman, and eunuchs. The ejmunafidhin are always eunuchs.

The alriba are few in number and all related to one another. They desperately seek to pass on their power to their offspring and often adopt alriba born to the lower castes in order to keep their families going. These children are always claimed to be their natural children no matter the truth. The alriba are ruthless, privileged, and quick to anger. They use their power to dominate others. Their palaces have open-air rooms devoted to massive bowl-torches set in the floor where they bathe in flame and consume that which they have burnt. Their use the khadivor to do all the labor they need to thrive, guard themselves with the mugerribim and keep the sabiqa as their advisers, the cometajir as their go-betweens for commerce, and the arturfi to make them fine things. An alriba's palace will have extended family within it. Children will be raised by the khadivor that serve there. The alriba live in luxury and pursue their passions.

The sabiqa are the next caste, privileged for their elite knowledge. As children, they are taken to a special school that teaches them a curriculum devised by their elders to indoctrinate them into their complex philosophy of consumption, the caste system, and flame. the sabiqa are often willing participants in enforcing the caste system, as they are indoctrinated from an early age and benefit greatly from it. After they graduate from their special schools, they are given luxurious apartments and many khadivor as servants. They also take on the task of educating (indoctrinating) members of other castes, keeping of libraries, practicing and controlling the use of mystic arts, and the spy networks of the country. They wear special brass emblems called jamrascura. These emblems allow them access to secret information and societies where forbidden arts are practiced. Men among the sabiqa are usually scholars, researchers, teachers, priests, and practitioners of infernal or heavenly arts. Women among the sabiqa are usually spymasters, librarians, teachers, priestesses, and practicioners of aetherial or nommic arts. Eunuchs among them are usually spies, scientists, introctination specialists, shamans, and practicioners of shebvic, poioumenonic, paradoxical, or mana arts.

Special among the sadiqa are the priesthood. Worship of the Burning is enforced in Azar. Priests are indoctrinators, priestesses are administrators. The priesthood, called the nftimo, practice a religion that requires bloody sacrifice (usually animals), rigid adherence to rules, and meditation via smoke-inhalation. The high priest of the nftimo is the only sadiqa whose power is close to that of the alriba. Laws prohibit the priesthood from gaining too much power, but they are much feared and honored.

The warrior caste of the muguerribim are the military, police, and guards of Azar. They are sent off at a young age to train as warriors. By age 13, they are selected to be part of one of the different warrior jobs: common soldiers, cavalry, aerial zailors, scouts, demolitionists/arsonists, city guards, bodyguards of the alriba, detectives, border guards, outcast-hunters, or the ejmunafidhin. Those who serve well in these and grow in power and skill can become one of the 12 kinds of elite warriors: the personal bodyguards of the maliko (haresplandiq), the assassins (fumardukhan), the blessed elite sworn to the Burning (shueletdios), the red elites who ride the great horses (jaladroja), those who dance with burning swords (sayfarra), or the blood-drinking madmen (kabirerno). They live in comfort and enjoy many privileges, including the right to have sex with anyone of a lower caste at their pleasure. A special code of honor exists among them, but it is twisted and involves a rite of burning themselves. They refuse to betray one another and believe themselves to be heroes deserving of great honors, which they will show to each other while denigrating lower castes. The artufri create grand weapons and armor for them.

Among the cometajir are very wealthy and powerful individuals. This caste sees the most desertion of all the castes, as they have the most resources to do so. Laws prevent them from living in luxury similar to that of the alriba or sadiqa, but their accomodations often rival the muguerribim. They are traders and merchants, but the laws of trading are set by the alriba and all resources are owned by the alriba. They must follow them closely and trade what they are told. They have leeway in making deals, but if they succeed, the alriba take credit, and if they fail, they are punished. They have many arturfi and khadivor serving them. Those deemed to be cometijar as children are taken in by cometajir families and raised to understand business. They compete for contracts with the alriba and access to resources, which they then attempt to trade internally or externally. Half of their wealth goes to the alriba, but they keep the rest (and many hide how much they truly have). The cometajir enjoy their comforts, but they are forced to work very hard. This instills in them a pride and a sense of accomplishment that often blinds them to their exploitation.

The arturfi are fine craftsfolk, artisans, creators, and skilled producers. They are artists, blacksmiths, masons, chefs, composers, sculptors, weavers, potters, tanners, armorers, machinists, sky shipwrights, and more. They are considered elite workers. They must create to serve the upper castes, but have a few more privileges than the khadivor. They often overseen khadivor in factories or other circumstances. As children, they are apprenticed early to the arturfi who will raise and train them. At the age of 16, they are tested. If they fail, they are required to train for seven more years. If they fail again, they are outcast. If they succeed, they become journeymen and later masters. Some have their own shops, but most serve a cometajir, sadiqa, or alriba, or the military or police. They are often seen wearing special clothing based on their craft, and they have basic guilds that help them struggle for rights. These guilds are identifed by the clothing they wear. There are strict laws the guilds must follow to have any influence, but there is often struggle to gain more.

The lowest caste is the khadivor, who are servants. They are paid, so they are technically not slaves, but they are treated about equally. They have little choice of where they work, subject to the whims of anyone of a higher caste, and they must do the work they are given. Most are children raised in orphanages because of offspring born to higher castes. Those born into khadivor families often have relatively happy childhoods, as their families seek to let them enjoy life before they are required to go to school at age 12 or work at age 16. Khadivor have many stories they tell of those who escaped or became a higher caste somehow. They dream of better, and they are disallowed by law from fighting for better. They do all the work the other castes don't do.

Any deviation from the caste system is punished by banishment. Outcasts are called maparibudh, and if they survive long enough, the usually find their way to the riverside settlements where other fyr-ka'ar fear to go. Legend says these settlements were founded by the Fyr-ka'ar Manifest, Kes-ka'ar Aluar. She protects them from the power of her son and his descendants. Among these settlements are a whole different and more equitable system. Everyone is taught to use their powers. Everyone is encouraged to take whatever role they wish. Everyone is allowed to express their gender as they choose. The settlements are led by elected councils of leaders, property is held communally or personally but never privately, and the Burning is worshiped in the old ways, through rituals of flame and smoke, dancing and song. Laws are only there to protect the settlements.

Every settlement has certain special roles. The council has a force of police who protect the community called the direprotegim. These forces answer to the community. The priestesses, called lideralnaar, are singers and dancers who commune with the Burning, and there is an elite group called the umllama, are Disciples of the Manifest. They have special powers and are called upon to answer the most difficult questions or issues facing the community. Finally there are the mutamaridin, warriors, spies, and infiltrators who seek to liberate fyr-ka'ar society from the maliko. These are in both the settlements and among the cities, where they foment rebellion and organize resistance. They are considered the worst criminals in all of Azar.

All fyr-ka'ar buildings are made (at least in part) of a brass imbued with rubedian aether. Certain flammable materials are forbidden within fyr-ka'ar society.