I settle things with a death duel. I challenge people with a surrender duel to find out who is a better swordsman~
Obviously this is slightly out of date, since duelling guilds can now use the training option on testing islands. But rules from the wiki
"Duels serious affairs meant to be used to defend one's honor, and may result in character death. They are not for sport or fun. As such, dueling guilds are prohibited if they use game-mechanic duels. Dueling guilds using roleplayed duels are acceptable."
I'm not 100% sure where we stand with duelling on stable right now. It is annoying that a option exists on testing that allows for things like duelling guilds or duelling to determine the best swordsmen, but not on stable. Might be something to bring up with the magistrates I don't know.
My feeling is duelling to surrender should still only be used to sort out slights against ones honour.