First, he went to buy potions and bought three healing potions in the periphery (if available). Then he came to the designated place.
-- So, you have arrived! Well, the duel is simple. We stand at medium range and fight. The potions will be here, on the grass nearby. We'll give the defeated one a potion, shake hands, and go our separate ways. It's like training, only a little more painful. Shall we begin?