Judge of the Change was a title given to an Imperial officer who was charged with presiding over a change of planetary Fief, declarations and forms of kanly, or War of Assassins during the days of the Imperium.
A Judge's authority could only be challenged before the High Council.
It was typically in the best interest of the new fief holder to demonstrate that the forms of the Great Convention were obeyed. As a result, both sides of a feud would generally treat the Judge with respect. House Harkonnen discarded this tradition by killing Liet Kynes when they wrested control of Arrakis from their enemies, the Atreides. They sent him into the deep desert and abandoned him.