The first contact with the people of Seggri teaches the observers that Seggri has rigid gender roles. Each town or village features a castle wherein the men live and train for the gladiatorial athletic games and compete to become master breeders. Outside of the castle are well-tilled fields, reclaimed from the barren ground through hard work. Women do this work, as well as all real work on Seggri. At first glance the visitors view the laboring women as beastly and dangerous, lumbering beyond the gates of the castle as they toil in the fields.
On their second visit, which happens by accident, the team of visitors - one male and one female - are separated when they arrive on Seggri. The male, named Kaza Agad, is sent to the castle, while the female, G. Merriment, is taken in to a motherhouse (a boardinghouse and makeshift community for women). Merriment’s reports paint a fuller picture of life on Seggri, as she details the role and responsibilities of women in the villages.
Women are responsible for every productive aspect of life on Seggri, including trade, food production, child-bearing, child-rearing, scientific achievement, and politics. They are at the forefront of any advancement that society makes, while the men languish in the castles, emerging only to service women and sire children. Men who show athletic prowess or prove capable of siring children are in high demand and spend a great deal of time with women in bordellos. Men who are accomplished neither in athletics or breeding are badly abused and prohibited from leaving the castle at all.
Merriment becomes very popular at her motherhouse and eventually goes to college. College is a privilege reserved for women and Merriment spends her time there learning about the rules of society on Seggri. The gender rules of society dictate that boys should be separated from their families around the age of twelve and sent to the castle. Most men on Seggri live there for their entire adult lives, leaving only to sire children.
There is a marked gender imbalance in terms of viable births, with a 12:1 ratio of female children to male children. Most male children are born sickly and die in infancy. Those who do survive can only hope to become popular studs once they reach maturity so that they can be shown favor in the castles and in the bordellos.
After months of being separated from Kaza, Merriment becomes worried about him. She asks around and eventually learns that he died in the castle - castle life is a lot more dangerous than initial reports suggested. The first account of life on Seggri from a male perspective comes from a man named Ardar Dez, who, like all men on Seggri, lives in the castle.
Dez details his experiences being sexually assaulted and tortured at the hands of the older, more decorated males, who treated the younger males as whipping boys. Following years of oppression at the hands of his overlords in the castle, Dez and his friends stage a rebellion, killing those who had brutalized the younger men, and argue for change in society. Their rebellion leads to some “Open Gate Policies” that allow men the freedom to leave the castle. Though these policies are a huge step in giving men a chance at social mobility, the free men find that they are unable to truly integrate themselves into a society that does not have a place for them.
“The Matter of Seggri” is a complex tale about gender as a social construct. In many ways, the relationship between males and females on Seggri mirrors the historical relationship between men and women in societies on Earth. One gender typically holds most of the power, while the other lives a more restricted life.
The title of the story is a play on this idea, as is the name of the planet, Seggri. The name "Seggri" is a play on the word "segregation". The unique thing about the situation on Seggri is that the women hold all of the power over men, as opposed to the other way around. In this way, Le Guin challenges the traditional gender power structure.
Due to a profound gender imbalance, males are considered fragile and almost useless when it comes to practical skills, but all-important in the area of reproduction. As their worth to society is based on their ability to sire children, they spend the majority of their time within the castle competing to become "champion sires".
As champion sires are in high demand, they are of great value and enjoy a higher social status than most men. In many ways the station of men in Seggrian society parallels that of women in many cultures on Earth throughout history. Throughout most of world history, women have been considered the weaker sex, fragile, and mostly useful for breeding.
The fact that men in Seggrian society can so easily occupy the place set for women in most Earth societies illustrates the idea that gendered behavior and gender roles are not innate. Rather, gender roles are created by society and people fall in line accordingly. The tail end of the story, when Dez realizes that he has no place amongst free people, drives home Le Guin’s final point that it is difficult, if not impossible, to set one's own course in a society ill-equipped to handle those who operate outside of society’s mores.