D&D 5E Barbarian / Sorc with 28 AC !

[Kobold Stew]

2. Apply circumstantial bonuses and penalties. A
class feature, a spell, a particular circumstance, or some
other effect might give a bonus or penalty to the check.
3. Compare the total to a target number. [...][/INDENT]
Note item 2 - I colored the most important part...
A ___.
That means, at least to me,
A feature = 1 feature
A spell = 1 spell (but noting the exception in spellcasting rules)
A circumstance = 1 circumstance (but none have been given that modify rolls that I've seen)
some other effect = somthing else.
The implication of the "or" is that you're only supposed to get ONE of them.

By the literal text, in the most literal sense, you don't get to add multiples unless they're spells... So either you're adding the Con bonus OR you're adding the Spells' bonuses, but I suspect that may be a bit too literal.

I don't think this is the way English normally works. Consider the sentence before the highlighted bit, which uses plurals: "bonuses" and "penalties". That suggests that the indefinite article in the next sentence ("a") is being used as an indefinite article, and not as a substitute for the number one.

You add any bonuses and penalties that apply.

 

[jadrax]

I can see why that realistically, you would rule that some stood behind an arrow slit would not get the bonus from a shield that is no longer even vaguely in the way of any attack that might hit you.

But then realistically, how many times are you going to be behind an arrow slit and using sword and board?

 

[DogBackward]

I can see why that realistically, you would rule that some stood behind an arrow slit would not get the bonus from a shield that is no longer even vaguely in the way of any attack that might hit you.

Except that you're not just pressed face-first into the arrow-slit. You can still bring your shield around and put it between you and the hole, thus still gaining its protection.

 

[jadrax]

Except that you're not just pressed face-first into the arrow-slit. You can still bring your shield around and put it between you and the hole, thus still gaining its protection.

At which point your kind of moving into total cover territory.

Compare: If you block the hole with your shield you get +2 AC. If the arrow slit has a shutter that you can use, you get Total Cover.

The fact that Shields operate independently of the Cover rules brings up anomalies. You take the big cover categories, like three quarters cover, and add a new one 'three quarters cover with shield'. Why do you get +7 AC for that, but not for say 'seven eighths cover'.

It's a can of worms.

 

[DogBackward]

At which point your kind of moving into total cover territory.

Compare: If you block the hole with your shield you get +2 AC. If the arrow slit has a shutter that you can use, you get Total Cover.

The fact that Shields operate independently of the Cover rules brings up anomalies. You take the big cover categories, like three quarters cover, and add a new one 'three quarters cover with shield'. Why do you get +7 AC for that, but not for say 'seven eighths cover'.

It's a can of worms.

This sort of thing is why I have a new motto for 5e: "This is why we have a DM." It's also one of the reasons I love 5e so much: we finally have a system that trusts the DM again. They trust that we can look at a situation, and figure out what makes sense.

I was originally just talking about standing in the space behind the arrow slit, not covering the hole. If you actually put your shield over the arrow slit? That's full cover: no part of you is visible to the enemy, so this is a pretty fast and easy ruling to make. Making those sorts of rulings is exactly why the game has a DM in the first place.