You are definitely at your dm's mercy but I see it as reasonable. One nhing to note, shields are neither light nor 'weapons' so there is no raw way to attack with a sword and shield ala two weapon fighting.MMh, guess I'll be at my DMs mercy then. Although I think the argument about a devotion paladin, using his shield as an improvised weapon and channeling Sacred Weapon on it might be a point. It becomes magical too, but the game does not have a distinction between 'battle magic', 'protective magic', and 'general magic', or 'whatever magic'. Magic is magic.
I was just covering general usage scenarios. As far as dueling and gfb/bb that is also up tomyour dm. All of those require a "weapon" which raw a shield is not.Who says I would do dual wield with sword and shield? It's just the shield and a free hand. Prone, grapple, pummel (with the shield), rinse repeat. The sword is just in case I can't grapple/prone.
Also as long as I use the shield as a weapon while having my other hand free (or grappling someone), I should get the +2 damage from the Dueling fighting style, wouldn't I. And Enlarge increases the shield's size, so I get an additional d4 to my damage rolls with the shield for a total of 2d4+6 (Str 18), when bashing skulls with the shield. Booming/Greenflame Blade, respectively Shield might add up, too. Booming Shield sounds better anyway.
Not much, but ok for a grappling defender, I guess.
As does the dual wielder feat but it has classicly not been allowed with shields for abusable reasons. I undertsand your interpretation Im just saying the interpretation that I have seen wore often is different. Basically all of nhis comes back to talk to your dm. Which is sadly usuallythe answer. <.<Yes, but taking an educated guess both Dueling and BB/GFB just state that they require a weapon. They do nowhere state that it has to be simple or martial weapon. Just a weapon. So an improvised weapon should qualify just the same, even by RAW.