While Nilfgaard's emperor wields absolute power, harshly crushing the slightest sign of disobedience, opposing forces continue to exist within the empire. By this I do not mean the disgruntled leaders of conquered provinces, but the amgantes within the City of a Thousand Towers who are unhappy with the current leadership. This conflict between the emperor and the noble houses of Nilfgaard the capital dates back to many years. All the princes of the blood and magnates expected their ruler to wed one of their daughters and sire and heir with one of their own. The emperor, however, had other plans. This proved a slap in the face of all the great families from which he refused to take a bride.
The Nilfgaardian opposition patiently waits for the emperor to slip up, for some event to occur which will weaken his authority, be it an economic crisis or a defeat in battle. A secret conspiracy lies ready to seize such a moment to incite the disaffected, assassinate the emperor and carry out a coup d'état culminating with one of their own number ascending to the throne.
For obvious reasons, only a limited few know of this conspiracy, but any shrewd observer of Nilfgaardian politics can read the signs of its workings. So long as men are men and the world is as it is, certain dynamics will forever be the same, and the discontented will always form subversive societies with their secret signs and hidden agendas.