The game is based out of the dwarven undercity of Tarran Tor. The population of Tarran Tor is exclusively dwarven. Founded in 918, Tarran Tor is a shining beacon of modernity. An advertisement to the glory of the great Guild of Engineers, fit to make the other undercities jealous. Founded by, and bearing the name of the great Tarranston clan, Lord Tarranston meant to demonstrate to the other undercities the real value of the Guild of Engineers. To this end, great engineering works were built into the initial excavations of the great halls. Proper running water, elevators, powered mills and many other wonders were designed into the first plans for the city layout.
All went well during the construction until the very moment of completion, when Moradin’s displeasure manifested itself in the great collapse of 946. In the space of a few moments, all contact with the rest of the Firstborn Empire was lost. All access to the surface was lost. More than half of the population was lost as halls crumbled and great caverns were cut off from the new settlement.
Tarran Tor would spend the next 10 years desperately trying to regain contact with the great empire without success. Newly excavated passages collapsed with alarming frequency, and the once-vanquished ratlings reappeared, leading daring raids through the newly opened passageways. This all served to keep the Tor on the back foot, struggling to survive. The decision was made to seal off the areas where excavation was underway, and instead focus on the defenses and security of Tarran Tor.
The years from 956 until 1032 were defined by a prolonged and bloody war against the ratmen tribes of the Vermin King Shrisskss. The ratmen were so intimately familiar with the layout of the caverns that they proved as elusive as smoke. Tarran Tor was bled nearly to death by the guerilla raiding tactics of the ratmen. The war was ended when Lord Tarranston lead an assault on the lair of the Vermin King and slew him before collapsing the surrounding caverns, laying waste to most of the warrens.
With the rat men leaderless, scattered, and without a home, Tarran Tor had a moment to lick its wounds and look to the future. It has spent the time since then excavating and exploring, hoping to one day rejoin the Firstborn Empire.
Despite the decisive victory over the ratlings, they remain an ever-present threat. They don’t attack in large numbers, and they typically only raid for the sake of food, but a group leaving Tarran Tor is never completely safe.