D: One Shot
It was a lie, sort of. Allowing them to choose.
The laws that governed the duel, within a system that was otherwise designed to run like an intricate piece of clockwork crafted from rules and regulations, were relatively simple. The participants could agree upon the terms, and the judgments on violations of that contract defaulted directly to a single individual.
The anim recording terms that must be met in order to make the duel valid under Corporate System law were more carefully defined, with specific angles and distances to standardize the measurements. Tradition, however, added a few things. Like the codes that allowed the challenged individual to choose the weapon and the challenger to choose the extent of the bout.