In World One, the term duel has had several definitions over the centuries. Usually, it is considered to be a form of ritual combat between two people, mostly for honour and often to the death, with matched weapons according to the individual's combat doctrine and style. In modern terms, the word "duel" applies to a battle between two fighter pilots in aerial warfare. Informally, however, the word can be applied to any instance of one-on-one combat. In works of fiction, this is usually what the term "duel" means, especially when the combatants are wizards, sorcerers, or other magic users. Such a fight is invariably described as a "Wizards' duel" (this form of duel is, understandably, very common in the Harry Potter continuum). The PPC uses all definitions of the term, but formal duels (and, obviously, aerial ones) are very rare.