The Goblin Tower is a fantasy novel by American writer L. Sprague de Camp.
The Kingdom of Xylar, one of the twelve city-states of Novaria, has a peculiar custom for choosing its kings, each of whom serves for a five-year term. At the end of that period he is beheaded in the public square before an assembly of foreigners, and his head cast into the crowd. The man who catches the head is drafted as the next king.