I'd like to see this added. I see it being a fairly straightforward thing from a gameplay perspective.
Add a new emote - "Challenge". Doing this will have your pirate pull his sword, slash an 'X' in the air in front of them and then point with their sword which they hold until the player decides to move or someone responds with the emote as well (like the "Make Friends" one). This would place the two into a duel (their names could change color for them, so they know who they are facing easier and others could choose to interfer).
In this mode, players can sword fight without threat within their own crew or with other crews. The players would also have to stay in a certain area to one another (on the ship if initiated there, on the island if initiated there, not optional in the water) and leaving that area would cancel the duel. If one dueler kills the other, instead of a trip to the Ferry they both Regen their health to full while the loser briefly takes a knee to denote the loss.
This would be great for picking up crew mates from other crews (I've seen many do this), and allows fights in the down time with our own team to practice our fighting chops in a safe setting.
If an outside party interferes with the duel it would be canceled immediately (this would only be possible in multi crew situations as teammates can't harm one another while not in a duel themselves).
I think that would generally cover it, unless I missed some glaring potential issue in this (think I covered them all). I'm sure it would take more work on the backend but this would be a super fun thing done in a method that is both simple but one that is basically already in play with friending (so it all fits with the existing game design).
Seen others propose this many ways, but I feel this is the most straightforward way to do it.
