This is the page for rules in duelling.
In order to be feasible, duels have to be completed by a judge. The only things you can do to increase chances of winning are to use your best weapons and choose your opponents carefully.
Duels are calaculated by your weapons bonus being added to a random number between 1 and 6, and the difference being applied as damage points. When someone reaches 0 health points, they surrender and the other player wins.
You can gain medals to prove you defeated someone, these medals are delievered after the match.
Weapon bonus and armour bonuses will be revealed at a later date.
Good luck! If you want to ask a question, contact Anti-Umbridge league!