I was playing the other day and my group had to fight animated armor. I thought, hey, since it is literally a suit of armor, and somehow this armor is giving it its AC, shouldn't damaging it reduce its AC? I just wanted to throw this out there, and if you have any thoughts, please share!

As a houserule I wouldn't bother because then you have the can of worms of why attacks against players aren't reducing their AC so either you apply this to all AC and introduce a needless complication and extra thing everybody has to track and you have to readjust the entire CR system and all battles in everything OR you leave it as monsters only or just this specific one which is an unnecessary nerf and utterly illogical. It's kinda 'lose lose situation' to me, so I wouldn't implement it. ¯\_(ツ)_/¯

I do understand he idea behind it, and it has merit, just not in this particular application. Keep thinking more on it, though, and you may have something interesting! 👍

Just as a helpful note for future: You posted this in Rules and Game Mechanics forum, which is to discuss the official Rules as Written. The forum you should have posted this in is Homebrew & Houserules because this is a houserule idea. I will see if a mod can move it for you.

Ok, thanks!