duel

On Red Alert 3 the Empire of Rising sun has a wunderwaffen called "Shogun executioner", a giant mecha with three robot torsos using eletric katanas. On Fallout 3 we got the Liberty Prime, the McCarthyist USA war robot on a 1x1 frontal combat in a plain ground, who would win?

In 1836, a young student at the University of Bonn got into a duel with a member of the Borussia Korps. During this duel, the student received a cut over his left eye. This student's name? Karl Marx. What if things went far worse for Marx in the duel, and he died?

On May 30th, 1806, future POTUS Andrew Jackson dueled a lawyer named Charles Dickinson in a dispute over a horse race. Jackson took the risk of letting Dickinson shoot first, hoping his quickness would hurt his aim. Turns out it didn't hurt it that much, since Dickinson's bullet hit Jackson mere...

With no PoDs prior to 1800, how can the practice of settling affairs of honor between men by way of arranged combat with matched weapons? What would be the knock off effects on modernity and world culture as a result?