The Recluce Saga, despite being a somewhat niche 'high fantasy' novel series, is perhaps one of the largest and most monolithic such series to have been written in the last forty years. Beginning back in the eighties and spanning more than twenty books now, it is LE Modesitt Jr.'s signature series, the series that propelled him from a somewhat eccentric author of varying science fantasy and science fiction novels and series to one of the quiet dominators of high fantasy as a genre.
The Recluce Saga setting is defined by wars, conflicts, and clashes between normal society and the mages of the two forces known as chaos and order. Chaos is energy, change, destruction, and entropy, whereas order is structure, reinforcement, defense, and healing/restoration. It is very easy, if you read the early books, to regard users of chaos as 'evil', and it is true that a disproportionate number of them are evil. Order users find it extremely difficult (painful and sometimes deadly) to be dishonest in any fashion, to kill, and even to touch edged weapons at times. Chaos users fling firebolts, break down the structure of objects, and corrupt/corrode the people and world around them. Chaos users and those who are touched by chaos are natural liars and deceivers, often selfish and ambitious, and they generally can't be trusted at all.
However, later books, regarding the foundation of Hamor and the Cyador era (both in the past) show that there are chaos users who escape the fate of those who not only use chaos but let it into their souls. Lorn'alte is a man who has the passion and ambition of a chaos user, combined with the idealism and sense of what is right that one who can also touch order possesses. In a nation built on the use of chaos, he sees what is best about his nation and strives to make it stronger, even as the forces of those whose ambitions are entirely selfish and those driven by irrational fears try to destroy him again and again. Lerial, the second son of the Duke of Cigoerne, has a journey from a somewhat petulant child of a chaos wizard to a mature adult who understands the costs and necessities of protecting the fledgling nation his grandmother formed. Perhaps the greatest gift these two series granted me, as a long-time reader of the series, was transforming white mages from faceless schemers and destroyers to people with cares and woes not so different from the average person, just enhanced by their power.
The earlier books primarily focus on events around Recluce and the order users. Recluce is a nation formed by one of the most powerful weather mages (weather magic being born of order) in history and a gray mage who was bound to him. Recluce is a nation born as a refuge of order users, who are often disliked by those in power because their benefits are subtle and their ability to see truth (and the knowledge they don't lie) is well-known to the average person. However, by the time of the first book (Magic of Recluce) Recluce is one of the greatest powers in the world (a defensive-isolationist power but still a power), with steam ships made out of black iron and mage-engineers forging weapons that no chaos mage can stand against. Most of the protagonists of the various arcs of the early series are young men who are idealistic order mages, who don't learn until after many painful trials and tribulations that the world is what it is and what is right is not necessarily what is. This is an issue for many young order mages, apparently, because of their tendency to view what is right as what should be (order mages have a tendency toward rational morality that is somewhat rigid). Moreover, as a result of their journeys through life, they experience suffering on enormous scales, as they must deal with the world's backlash to their attempts to make it better. Many end up unleashing terrible destruction and change upon the world, ironically creating the very chaos they themselves sought to reduce.
And that comes to the nature of the Balance. In the world of the Recluce saga, the two forces are always, no matter what, evenly matched. For every iota of order energy in the world, whether bound in objects or free in the world, there will always be an equal amount of chaos present. As Recluce builds itself up, chaos mages become more plentiful and powerful, and it becomes possible for Recluce and artificers in general to make better and more effective weapons from iron and steel, thus also incrementally increasing the amount of free chaos in the world.
Most of the protagonists in the Recluce saga are good people at heart, often forced into situations where they have no choice but to kill, destroy, and bring about change in order to make things better for the future. They are people who can see beyond the immediate, who often see generations and centuries into the future, and they possess the inner steel necessary to change things... even as their actual desires are often more humble in origin, to have a family, to be able to work a forge without fear of caprice from the powerful, to see that their female children not be used as chattels, etc. This is a theme throughout most of Modesitt's fantasy, as the basic motivations of his characters are humble while resulting in great change, because of the expanded viewpoint they gain as a result of their journeys through life.