[Varyon]

Dueling isn't something I considered for my Harpyias setting (which is Space Opera), and doesn't really fit any of the major powers, but there could certainly be some minor cultures that use it. A moderately common melee weapon in the setting is a retractable vibrokatar with a built-in shock effect (comparable to the zap gloves from UT), which is itself often built into armor. Using such, along with armor, is likely for a duel - you basically try to penetrate each other's armor to deliver the electric shock. For most duels, the weapons would be set to simply shock and incapacitate the enemy, but for more serious duels the "kill" setting would be used.