"Magic is like telling a lie," Calypso told his latest bunch of would-be apprentices. "It doesn't matter if it's real or not as long as everyone believes it."
"Uncle Humblestaff?" the young hero responded. "Of course I know the man. Wouldn't have had a chance at the academy without a word from him. He's the big guy over there, surrounded by all those adventurers."
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.