The literal interpretation of the spell is that it just sets your AC to 16 if less.Not to open a can of worms but why wouldn't shields work? Shields don provide an AC like armor, they provide a bonus. My minimum AC is 16 so why would a shield not add to that?
The issue is that this is your interpretation, not what people find to be the "obvious" reading of the spell.I don't see the issue. In 5E, there are things that set your AC at a certain value and things that give a bonus to AC. I'm pretty sure that things that give a bonus to AC should stack, while things that set your AC should not. So, barkskin stacks with a shield (it gives a bonus to your AC), but not with Dexterity (it doesn't give a bonus to AC, your AC is set as 10 + Dex modifier instead).
The issue is that this is your interpretation, not what people find to be the "obvious" reading of the spell.
The issue is that you assume things to be neat and well thought. The spell does not mention any of the things you mention, it just says that the AC is minimum 16.
Which in turn means that the spell stacks with a shield, except when it doesn't.
Broken.
Barkskin clearly uses the first language,
If we had a spell that puts you on nonmagical chainmail for up to one hour, 2nd level, concentration required, would it be broken? I don't think so. So, where's the brokenness?
The problem is that barkskin does not use the language you claim it uses. It uses language that is used nowhere else in the rules: "target's AC can't be less than 16, regardless of what kind of armor it is wearing."Sorry, but it's not my interpretation, it's the rules as written. If you go through your PHB, you'll see that sometimes the language used is "your AC is XX". In other places, the language used is "you gain a +X bonus to your AC". Barkskin clearly uses the first language, and this is the reason why it can't stack with armor, dexterity, or anything else that uses the same language (such as constitution or wisdom, for barbarians and monks, respectively). Shields, on the other hand, uses the second type of language, much like cover or the shield of faith spell. A druid should be able to stack barkskin with a shield in the same way a barbarian does with the unarmored defense feature.
Not to open a can of worms but why wouldn't shields work? Shields don provide an AC like armor, they provide a bonus. My minimum AC is 16 so why would a shield not add to that?