What is a knightley contest?

Answer 1

A Joust was one form of "Knightly contest", bidding two mounted knights against each other, striking the other knight was the simple intention, but breaking your lance on them with the force was better, and actually unhorsing them was better still. This showed the knight's competency at mounted combat.

The other most common form of "Knightly contest" was the Melée, where the term used to describe armed close combat comes from. Although knights did not usually kill each other in these mass fights, they would use their close combat skills to grapple/throw/disarm/takedown the other knights in order to capture them and frequently ransom them in order to profit from the ransom.

One key disadvantage in such armoured combat was that a knocked down opponent was a sitting duck in heavy armour, which was why medieval manuscripts show a lot of unarmed/close-armed combat but yet never featured any "ground work" like seen in modern MMA.