All magic is suddenly gone. No mage can sling sorcery anymore. This upsets all empires and civilizations. It is soon discovered though, trough the combined work of mystics, scholars and dreams, that all the magic has been drawn into a single orb in a vast tower located at one of the poles. Whoever gets there first wins the greatest price in history, access to all the magic in the world. But who owns the tower?
In cases where a person has accused another of a crime, but there are no other supporters of the accusation or defenders of the accused, and there is not enough evidence to support one party or the other, the two people involved, or their champions in some cases, must duel in the presence of the local ruler or leader. The loser is assumed to be lying and punished accordingly.