The problem with that is that a bunch of the weapons you can get are two-handed weapons, which you obviously can't use at the same time as a shield, so either the artefact system would have to be changed so that you conditionally had the shield slot enabled/disabled (and various one-handed weapons would have to be nerfed so that two-handed weapons weren't always inferior) or you'd end up with something rather immersion-breaking.
Also, there's no such thing as attack/defence when it comes to personal combat skill, so a shield would have to affect PCS (like armour does) or you'd have to change the duel system significantly again (which isn't trivial) and/or you'd have to script in specific "Your shield protects you!" outcomes for various events (which, unless the shield could get destroyed, would risk making shields overpowered compared to other options, and which also might require changing how armour works).
I partially agree, I will admit that I have no idea how difficult it would be the introduction. I'd guess It would be as difficult as helmets which Woifee, you are a completely right. In all aspects. That said, the only thing I disagree, is most weapons are two handed. The zweihander obviously, but most swords historically were used with shield. from longswords, broadswords to scimitars. also lances. No noble would use a lance unmounted and even if shieldless they would use it one handed. Maces can be used as well as axes, both one and two handed, a smart guy would use a shield with it and a helmet!!! Bows are quite a different story agreed, but heck this, unlike most people think horse archers did use shields. Small as I understand but they did. I believe, the mongols used a small wood and wicker shield that covered the off hand forearm. Also not all cultures need have one, substitute a shield for... something cool.
The lack of use of shield came with gunpowder hand weapons, just like armor got smaller and smaller every century after that. and the idea of sword combat without shield was specific to some cultures on some periods such Scots Germans and others, until the duel for honor became a thing of prestige rather than a means of settling disputes. That's when you see the rise of the epée, rapiers, and later foils. Sabres were there, way before, but changed quite a lot. I would say shields were a mainstay for -nobles- until well the end of the 14th century and common later until basically disappearing in 15th. I'm not counting Samurais there though!
Cheers,
Dan
Edit: I can't see it being a major rework. honestly. Make it a different flavor of armor. It's already there. But like I said I know that I know nothing. so that's something. Or not.
