Righteous Challenge

An ancient Andu law gave any wronged warrior of good standing in the tribe the right to challenge a chieftain that had committed a crime against the warrior or a dependent of the warrior. The law over-ruled the normal rights of a chieftain, and prevented the chieftain from simply having their champion or a group of warriors defeat the challenger. The Right fell into dis-use during the migration from Aduria as the need for strong consistent leadership became paramount in the hostile lands of Cerilia.
When Roele formed the nation of Anuire with the twelve dukes, he agreed to constrain his power over the independent dukes by following strict requirements drawn up the the new clergy of Haelyn on accusing and punishing nobles of high birth of crimes, which included gathering evidence of the noble's wrong-doing, presenting it to a council of the nobles peers, etc.
The Right of Righteous Challenge was revived by Roele himself to deal with a rogue Baron in Hjalstone on the spot - he needed to deal with the baron immediately to prevent the Hjalstone uprising spreading along the recently conquered lands of the western Taelshore and to make a very public statement of how wrong-doers would be punished regardless of rank or nationality in his new empire, further he had made overtures of peace to a number of jarls in the east and unless he proved that he would defend them as he would his own nobles, the jarls would never accept him as their emperor.
The right to issue the challenge has been reduced sharply over the years - few nobles were as skilled at arms as the ancient Andu chieftains after all. In modern times (in most Anuirean realms) any challenger must also be of similar rank to the challenged, the crime committed by the nobles must also be proportional to their rank before a challenger can issue a Righteous Challenge and even then a champion can often fight in the noble's stead, particularly if the champion is the noble's heir.