Dragonmarked Ascension War
Eberron is a fantasy world where medieval tropes of swords and sorcery mix with the ideas of the Enlightenment, and a civic infrastructure that assumes magic is good for more than killing things. As opposed to the typical fantasy world where people live in plague-ridden filthy thatch cottages and reap fields heaped in horse-crap despite the fact that wizards can bend space and time and control the weather, the progress level of this world’s societies has advanced based on access to magic rather than fossil-fuels.
Buildings are stronger and larger than mundane architecture would allow. Trains and flying ships are powered by magnetic lift-stones and bound elemental spirits. City lighting, plumbing, weather control, mage-bred livestock and agriculture, communication through enchanted stones, sanitation, entertainment, medical services, and of course, warfare adaptations are all possible because of the way that engineers have infused magic into the day to day lives of the people. At least in larger cities. Because even if something is possible, it doesn’t mean that the majority of lands can hope to afford it. While the wonders achieved are comparable and even sometimes superior to modern Earth, the costs per enchanted item make large scale innovations exorbitantly more expensive than non-magical engineering.
There are 5 major human kingdoms on the main continent of Khorvaire.**
Cyre was once the greatest of kingdoms and crown jewel of progress, but years ago when an arcane nuke went off, the entire land became a wasteland shrouded in fog and lethal hazards.
Aundair is a paradoxical feudal monarchy. Whereas the well-to-do enjoy a highly advanced scholarly society, delving into arcane studies and fantastic splendor, the common class of agriculture-cultivating peasants making up the majority of their populace, have lives little more advanced than standard medieval peasants. Aundair has the most powerful of personal wizards and man for man cannot be matched in pure arcane skill, but has not yet undergone the work of magical engineering for the common people. The abundance of farmland helps to keep people well-fed and drunk, even if no concern is given towards their education, liberties, and cultural happiness. Things in Aundair are good enough to get by for most, but criminally disparaged when compared to the upper castes. Nevertheless, the propaganda of art keeps the majority of the peasants too swollen with cultural pride to ever consider a shift in the status quo. Think of Renaissance France for their level of arts and culture and manipulative politics, as well as a callous willingness to let their poor stay in the Dark Ages, only with enough sense to keep them from starving and revolting.
They fight their wars with standard medieval armies backed by powerful wizards and mage-knights.
Thrane is a theocracy in all but name, where divinely-empowered clergy command a rigidly conservative, traditional ruling class based upon the tenets of their religion, the Silver Flame, all while often living quite hypocritically behind closed doors. While the majority of their people are creative, decent, and live good (if austere) lives, sometimes the zealotry of these people cause an atrocity of frightening scale. For example, a century-long campaign of ethnic cleansing of all people of lycanthropic origins which nearly made were-creatures and other beast-shapers extinct. Thrane resembles the Papal States of Renaissance Italy in culture, arts, and religious tyranny.
Thrane fights their wars with ritual prayers from their clergy, swarms of well-trained peasant archers, pikemen, and holy knights as heavy cavalry.
Karrnath is a hybrid of Fascist and Feudal values in a pseudo Germanic/Slavic state whose powerful aristocracy command legions of the walking dead as well as terrifying personal skill-at-arms. They are a nation bred for warfare and man for man have the finest soldiers of any of the main kingdoms. This flaw of being too military-minded shattered their culture when the civilian infrastructure all but collapsed in a manner similar to the Soviet Union after the Cold War. Their solution to massive outbreaks of plague, low birth rates, and casualties from starvation and logistic failure, was to empower necromancers to recycle their dead as tireless soldiers that need not eat nor sleep. While the strike teams of elite knights still commanded and plowed into the thick of the fighting, the peasant arm of battle was all but replaced by the walking dead. This innovation allows Karrnath to experience an eery prosperity as each living citizen has little burden of backbreaking labor, freed from the yoke of providing for manufacturing and agriculture, and is now free to attend to innovations and professions, such as either controlling the undead labor projects, or getting involved with the military.
Karrnath fights its wars with its dead, and after battle rages, the other sides’ fallen as well. Where the skeletons and zombies lack the skill and tactical innovation, powerful unholy knights and necromancers keep things interesting with horrific monstrosities of undead monstrous creations like putrid siege engines and weaponized pestilence to strike the battlefield.
Breland is a cosmopolitan mercantile center that accepts all creeds, colors, orientations, and baggage so long as taxes are paid and trade is not inhibited. If they had a superpower, it would be a toss-up between their money and their technology. Breland is a socially liberal but economically conservative constitutional monarchy, where the monarch controls expedient matters of warfare and short-term disputes, while deferring to an elected council for law-making and reserving authority to overthrow an edict with enough of a majority vote. Breland above all the other kingdoms has embraced magical technology on a civic scale, enjoying a city with mile-high towers, and every conceivable innovation to smooth running of the major settlements. As great as this all sounds, with such social freedom comes the cost of a poorly regulated populace, and an unnerving amount of crime and unchecked poverty and economic exploitation. If Amsterdam and Elizabethan England had a baby, it would be Breland.
The Brelish people approach warfare as a business. Mercenary peasant infantry and exceptionally expensive and well-trained elite forces give Breland a combined-arms approach that cannot be matched in its versatility of tactics. They are known for the extensive use of engineering efforts and special forces to replace the idea of a large swath of men fighting on the ground. When their peasant soldiers must fight, they use crossbows as primary arms, and only draw swords as absolutely last resort. During the Last War, they even created clockwork robotic creatures called Warforged to do the base-level fighting for them, but such practices have been outlawed.