A Sconce is a jurisdictional district of the magico-legal system. The pre-catastrophic system had the sconces, headed by archmagi having original jurisdiction in matters of magical law within their sconce, organized in an international system historically rooted in the feudal relationships of Equine nations, e.g. the ensconced archmage of the Isle of Yore had as a superior the court archmage of the Grand Duchy of Eastern Ponyland.
In Harmonia, the system of magical sconces remained roughly the same, but feudal court archmages were replaced as the superiors of ensconced archmagi with a system of state Curacies.
The Courts of the Ensconced Archmagi are the only courts with original jurisdiction in magical law. Sconce personnel attempt to prevent, detect, and halt violations of magical law. The Archmage (or sometimes his/her Magistrates, in large sconces) try cases before the court using an Inquisitorial system, in which the magistrate attempts to ascertain the facts of the case. The Quaestor's Office is responsible for the investigation, but is not specifically attempting to 'build a case for prosecution', rather, to gather both evidence for and against the accused for consideration by the court. If enough evidence of a violation has been accumulated by a preliminary investigation by the Quaestor's office, in the judgement of the Archmage (or magistrate), the archmage may direct the Quaestors to make further specific investigations, arrest and interrogate suspects, interview witnesses, etc. Unlike in non-magical criminal trials, the accused almost always testifies in the case, though usually in written form - indeed, most proceedings of the magical courts are conducted in writing, and actual appearances by advocates or parties before the magistrate until the pronouncement of the verdict and (if applicable) the sentencing are the exception rather than the rule. Most sconces have very limited facilities for holding accused, and in the past they used to employ geases to ensure compliance with the orders of the court, but this practice has been abolished under Harmonia. Instead, criminal defendants believed to be a flight risk are usually kept in the local jail under an appropriate agreement with the non-magical authorities. Historically, the reason for the preference for written communication is that archmagical sconces were large, it often taking several days of travel to reach the Tower of the archmage from the outermost limits of his/her jurisdiction.
The Curacies have courts of appeal at which the decisions of the archmagi's courts may be contested. The final court of appeal, as in all judicial matters in Harmonia, is the Harmonic Court of Final Appeal. If the Court of Final Appeal decided to hear a case appealing the decision of a Curial court, the College of Archmagi would appoint appropriate members with relevant experience and no pertinent conflicts of interest (e.g. from a different Curacy) to advise the Court of Final Appeal on pertinent matters of magical law and fact, and the Curacy being appealed would send officers to argue in favor of the Curial court's decision before the Court of Final Appeal (which uses an adversarial system.)