Level
1st
Casting Time
1 Action
Range/Area
Touch
Components
V, S, M *
Duration
8 Hours
School
Abjuration
Attack/Save
None
Damage/Effect
Buff (...)
You touch a willing creature who isn't wearing armor, and a protective magical force surrounds it until the spell ends. The target's base AC becomes 13 + its Dexterity modifier. The spell ends if the target dons armor or if you dismiss the spell as an action.
* - (a piece of cured leather)
I'd say the target gets to choose. However, if a creature has a natural, unarmored AC higher than 13+Dex, IMO you'd still have to beat that to injure it.
I like where your heads at, but I think that when you cast the spell it is negated if you are wearing armor, therefore it wouldn't take effect. (so unless you are talking about a creature that has a better AC without armor then the spell offers my interpretation is it wouldn't help you with your attempt. Keep challenging though
Would this interfere with the feature
Your speed increases by 20 feet while you are not wearing armor or wielding a shield
So would that character lose that extra 20 feet of movement?
This is absolutely wrong according to the sage advice which you yourself posted.
"Can you use a shield with mage armor? Mage armor works with a shield. Shields are grouped with armor in the equipment rules in the Player’s Handbook, but various game features distinguish between the armor you wear and a shield you wield. Take a look at the monk’s Unarmored Defense feature and compare it to the barbarian’s version to see what I mean. In the monk’s version, you must both forgo wearing armor and forgo wielding a shield if you want to benefit from the feature, whereas a barbarian must only forgo wearing armor."
It's unambiguous. Shields are not armor and always add +2 to your AC unless otherwise specified, as in the monk's Unarmored Defense.
Why does the spell use the Dex modifier? Wouldn't it make more sense for it to use your spell casting attribute?
u wanit
By that logic you would not be able to use a shield while using mage armor...
I believe mage armor stacks with unarmored defense and here is why.
Mage armor says, "The target's base AC becomes 13 + its Dexterity modifier." Pay special attention to the word "base." Without that word the spell would negate the effects of shields and feats sutch as 2 weapon fighting. For this same reason I see no reason why you could not add the constitution from unarmored defense.
@Mindful1, that's it? Really? So no shields or feats that increase AC? And if it does stack with those, why not unarmored defense?
@ Kevlar_vest Sorry, but I know they don't actually intend that based on what they've said in the past. If what you were saying was true, unarmored defense would say that you can add your constitution for barbarians or wisdom for monks, like the dual wielding feat does, instead of saying your armor class becomes 10+dex+wis or con. That being said the DM has final say on what rules are used so they can overrule it if they think it's fine.
Guys, it's not that hard to understand. You can only use one effect that changes your basic AC calculation method. If you're using Mage Armor, it changes it from "10+Dex" to "13+Dex", with Unarmored Defense you change it from "10+Dex" to "10+Dex+Con" or "10+Dex+Wis". If you're wearing armor, it changes it to whatever it says on the armor. The easiest way to think about it is that you're just giving yourself layers of defense that don't reduce anything that passes through them. So if an attack can get through your 13+Dex armor, it then goes against your 10+Dex+Con Unarmored Defense, aka your Barbarian's not-as-squishy body, and since you're wearing armor, it probably isn't strong enough to resist the attack still. Same thing with Mage Armor, if it's getting past the magical barrier created from Mage Armor's 13+Dex, it's going to your probably squishy 10+Dex body and we already know it fails that. This is why at the end of the day the Sage Advice is that you can pick whichever AC calculation you want, and to simplify it, you're gonna want to take the one that gives the highest end result, which means anything else would be lower anyway and not be able to resist the attack.
Meanwhile, a shield doesn't modify your base AC calculation, it adds to it after the fact like Bracers of Defense but without the "no armor" restriction. Not all attacks are going to hit your shield but you can occasionally block things with it. I personally look at different hit results as how I avoid damage, if it's in the dex mod range then I dodged it, if it's in the shield's range then I blocked it with the shield, if it's even lower than the base 10/13/etc. then it was just way off the mark. If I'm using Mage Armor and it's 11-13, it can't get past the magical barrier. If I'm a Tortle and it's lower than 17, it can't break past my shell.
Mage Armor + Tough As Nails is... ok?
"Unarmored Defense doesn’t work with mage armor. You might be asking yourself, “Why don’t they work together? Mage armor specifies that it works on a creature who isn’t wearing armor.” It’s true that the target of mage armor must be unarmored, but mage armor gives you a new way to calculate your AC (13 + your Dexterity modifier) and is therefore incompatible with Unarmored Defense or any other feature that provides an AC calculation."
From Sage Advice Compendium.
Thank you, super awesome response and first person to explain. Thanks
Sorry, I didn't realize you asked that two years ago and already had gotten responses.
Why does D&D Beyond show oldest comments first anyway?
Because base armour is 10 + dex.
Also dex makes the most sense as you'd be dodging. Remember it's the target's dexterity also.
You are only allowed to choose one way to calculate your AC out of however many options you are given. Some rules are exceptions to this, such as a barbarian being able to use a shield as apart of their Unarmored Defense, while a monk cannot. The way I like to think about it, is that if you used a different type of AC calculation on a monk (such as mage armor), then it would hinder the monk’s focus because they have a magical force on themself that they are not used to, and it affects the way that they defend themself, hence, taking way their ability to add their Wis modifier to their AC. (Sorry for the really long sentence).
Ultimately, though, it is up to the DM to decide whether or not they stack.
Now for something completely differnt: Is there an actual, mechanical reason for why the target cannot be wearing armor??
I mean whats the point, if my armors AC is higher then why would I cast it, and if my Mage Armors AC is higher, why would I wear armor? Or is it just to avoid using it as a diet shield spell à la "As soon as the enemy turns out to be able to hit through my armor, I cast Mage Armor!"?
Reason for why I'm asking: I have a not-yet Invocating Warlock with chainmail, and I kinda like the flavour of still having chainmail (see: Frodo in Moria), so I'm wondering if I gotta get into permanent casual wear to benefit from Armor of Shadows.
(And probably unrelated: Is the reason why Chain Mail and Chain Shirts count as heavy and medium armor respectively purely for balance, or is there some historical niche fact that justifies needing 5 minutes to put on a shirt?)
I like to do it the other way around. Take this scenario: You have Mage Armor, a shield and 16 Dex.
Now, If you're hit with a 10 or below, it's a flat miss. If you're hit with a 11-13, you dodge/parry it. If your hit with a 14 -15, you block it with the shield. And if youre hit with a 16-18, your Mage Armor kicks in.
See it this way: The higher an attack roll, the worse you are hit/the better it was aimed. So it would make sense that you use your defensive gear only for the bad hits. Or in other words: Why would an 11-13 breach through your dodges and hit the Mage Armor, if you can dodge a 14-16 just fine. That just doesn't make much sense, right?
Nah it takes less than a minute to put on a chain shirt irl. they just feel like a really heavy shirt.