Over the last eighteen months, the Australian podcast the Dead Prussian has asked each of its guests a simple yet deeply contested question: “What is war?” Answers have ranged from Professor Hal Brand’s insightful “war is a tragic but inescapable aspect of international politics” to my own citation of John Keegan’s “war is collective killing for some collective purpose.”Nobody so far has said that war is a “game”. Thankfully this isn’t surprising; anyone who has fought in war, or just studied it, will be aware that this would trivialise the destruction that can lie within. But it is also of note that nobody so far has labeled war as a duel.