Duel" is a web based interactive fiction by Piato, entered in the 2015 interactive fiction competition.
The PC is a wizard, in a duel against another wizard. You have a short list of spells to choose from, though you can use each one only once. Through a series of failures and restarts I was able to figure out which spells were more or less effective. I managed to make it to the third test before consulting the walk through for a complete solution.
Spells and their effects are described in verbose prose, some nicely written, some almost incomprehensible. In all, I think this is too densely written to convey a sense of danger or urgency which I would think should be the desired mood in this type of story.