Benjamin William Bova: Stories

Dueling as a means of settling disputes has been revived by the invention of the dueling machine, which allows two adversaries to have at each other in the imaginary world of their choosing, with no danger to either other than humiliation and the loss of the point in dispute, until the Kerak Worlds found a way to kill with the machine. Unless a young Star Watchman can solve the mystery, the warlike Kerak Worlds will gobble up the planets.

Ordinarily the military least wants to have the others know the final details of their war plans. But, logically, there would be times.