The Fencing Lessons side quest is available once the Broken Flowers Main Quest is completed. It involves Geralt returning to the var Attre villa, and then speaking to Rosa. Rosa wishes to be taught some fencing skills from Geralt, but wants this to happen on a nearby bridge. This eventually leads to a duel between the two, and Geralt being tricked.
Fencing Lessons is one of the shorter side quests in The Witcher 3, but it’s one that stands out – mainly due to Rosa. She’s far from the stereotypical female character in this era, and is even willing to trick Geralt. The quest also asks some difficult questions of the player, which is one of the main aspects to Geralt’s character development. A quick quest, but one that is well worth experiencing.