Can a Dex-based Aberrant Mind sorcerer/paladin do better than Mage Armor?

Question

A friend of mine is building an Eladrin Aberrant Mind sorcerer/Oath of Devotion paladin, but has decided to be Dex-based and not wear heavy armor. Most sorcadin guides we can find just assume heavy armor, so we can’t find much in the way of other options. If Dex-based is mentioned at all, the guides only consider Draconic ancestry for its scales. This character is Aberrant Mind for fluff reasons, but no guides seem to consider it (I suspect all of them were published before Aberrant Mind was).

So right now, his character is planning on Mage Armor for AC (and Shield but that’s only available sometimes). He even took the Defensive fighting style for the +1. Are there better options available to him for armor here? (Even given his low AC, can Defensive really be justified here?)

Current breakdown is Paladin 3rd/Sorcerer 5th, but that could still be tweaked; they’re currently 8th level and are probably going to stick to the 8th-10th level range. Aberrant Mind is fixed, and Eladrin and Oath of Devotion aren’t much more flexible—answers can make a case for alternatives, but they should ideally be small variations (so a naturally-armored race probably won’t fly). Answers can make an argument for levels in other classes, but it’ll be a tough sell (has to not just provide more AC, but also be a net positive even when you’re losing Devotion or 3rd-level spells). Magic items are also iffy; it’s not clear what will or won’t be available; they’re certainly staying at mid levels. Otherwise, WotC-only, no UA.

Answer 1

Serpent Scale Armor AC outperforms all other armor for dex users at your level, unless +3 half-plate enters your game.

Serpent Scale Armor (Candlekeep Mysteries, Book of Cylinders, thanks Wyrmwood!) is an Uncommon magical scale mail that lets you add your full dexterity modifier to your AC on top of the 14 base. In addition, it doesn't give you disadvantage on your Stealth checks. Its presence isn't guaranteed, but as far as things you can go looking for, it's definitely in the reasonable end of the loot wanted pool.

Except in this case you could (much less likely) wear a robe of the archmagi, which is 15+full dex mod, and some other boosts to your sorcerer spells. This is in the realm of hopes and dreams and probably isn't a consideration for your game if it caps at level 10.

Absent these two things, mage armor is most likely your best ac option nearly all the time, but I would consider trading it for heavy or medium adamantine or even mithral if you can get your hands on those uncommons; smite slots are precious and you don't have warlock levels to get mage armor at will.

Fighting Style

If you're planning to get swung at, +1 AC is always a good plan (unless you want to get hit for something like Armor of Agathys). With that said, as Wyrmwood points out, mage armor doesn't work with this fighting style; so it's a commitment to using actual armor at some point. It will allow studded leather to match full plate in performance at +5 Dex, and half-plate to do the same at +2 dex. Serpent scale outperforms plate at +4 dex with this fighting style.

In the realm of other classes

Has bard been considered instead of sorcerer? If a sword bard, they can get a meaty boost to their AC on defensive flourish anytime they hit with a weapon- which they'll be doing a lot with max dexterity, I imagine. Loses access to shield, but gains an AC boost that doesn't use its reaction in its place.

At level 9, it will let them take 6 bard to pick up extra attack, freeing them from the obligation to go past 4 paladin, and secures them 8th level multiclass slots instead of 7th.

P.S. If your DM abides by magical armor resizing to fit...

Serpent Scale + Polymorph = Mecha Kong.

Answer 2

Mage Armor is probably best

If we assume Dex is maxed, (16/17 at 1st, 18 at 4 and 20 at 8) and because Paladin, proficiency in Medium armor and shields. (Would be heavy if Paladin was first class)

• Studded leather = 12 + 3-5, 15-17 plus 2 when wearing a shield
• Half Plate = 15 + 2, or 17 plus 2 when wearing a shield
• Plate (if heavy armor prof) = 18, plus 2 when wearing a shield
• Mage Armor = 13 + 3-5, 16-18 plus 2 when wearing a shield

So it depends on your Dex, but if it's maxed out, then Mage Armor is your best bet, ignoring magic or materials. Mage armor also avoids proficiency, maximum Dex mod, disadvantage on Stealth and Strength requirements. Mithral (if available) would only avoid the last two items.

This may change with magic items or class features. For example, +1 Studded Leather armor would be equivalent to Mage Armor and not cost a spell slot.

Fighting Style: Defense

If the character took Defense as a fighting style, then, strictly speaking Plate would be the best AC (if the character had heavy armor proficiency) but only by one and with the 65 lb. weight cost, minimum 15 Strength requirement and Disadvantage on Stealth.

Since Defense only applies

While you are wearing armor

You wouldn't benefit from this with Mage Armor. I would recommend another fighting style.