Medium Armor Master is a decent feat- for an absolute beginner.

[diplomancer]

So, my 8 year old nephew has discovered my brother's old TSE-era D&D books and became fascinated by them. So much that I decided to gift him the PHB in our native language. 1st thing he said, after screaming with delight, was "I've got to make my character"

So I decided to help him, asked him first what race he wanted to be: human. Ok, now let's read the brief class descriptions, what do you want to be? A Ranger. Ok, we've rolled the dice and he got a lot of even rolls, so I decided to make a V. Human, and then at the end just choose a feat for him

Having finished making his character, went to take a look at the PHB feats, and realized how at once simple and effective getting Medium Armor Master would be. My nephew told me he wanted to be good at sneaking, so he'd chosen the leather armor, giving him 14 AC. But if he got Medium Armor Master and Scale Mail, he'd have 17 AC and still be good at sneaking.

So, +3 to his AC, and he doesn't even need to think about it or understand complicated mechanics. It's absolutely true that other feats could be more effective, but I don't think any other could be at once this effective at his current level 1 and also this simple to use, just put the proper number on your sheet and you're done.

What do you guys think? Good idea? Some other suggestion that would be simple enough for an 8 year old kid who's making his first character? My other choice was alert-definitely a better feat, and simple enough, but one that would require him to remember and understand more game rules.

[Mastikator]

Let him play what he wanted to play.

[diplomancer]

Let him play what he wanted to play.

Thank you for that, very useful. Except he is playing exactly what he wants to play, a Human Ranger. V. human is human. I don't want to go explaining to him "oh, there is regular human, and there is variant human who has less stat bonuses but an extra feat and a skill. A Feat is bla bla bla..." With the stats he rolled, some other races would probably be better, but I wasn't about to tell him "actually, you would be better playing a..."

He got so excited with his character that, when we had to break off our character creation session for a few hours, by the one we went back he already had him fully drawn.

It's also because he said he wants to be sneaky that I thought Medium Armor Master would be a decent feat.

[RogueJK]

As a free feat (no ASI alternative available), I agree that its value improves a little, especially at early levels. Medium Armor Master is typically examined in the context of an ASI. By the time your first ASI rolls around at Level 4, basically any DEX-based character will have access to Studded Leather, and going +2 DEX for 18 DEX with Studded Leather makes more sense than taking MAM and staying at 16/17 DEX.

However, even as a free feat, its value is limited in the long run on a DEX-based character. A DEX-based character will eventually want to have 20 DEX. And 20 DEX with Studded Leather is only 1 AC point less than 20 DEX with Half Plate and MAM. So you're effectively spending an entire feat on +1 AC, which isn't really worth it compared to all the greater benefits of so many other feats, although it may be worth it in Tier 1 while your DEX is lower and the benefit is closer to +2 or +3 AC (such as a low level one-shot, or a campaign that's going to end at early levels).

In the long term, it's only really useful for niche builds, like a PC who fits all the following criteria:
A) Has access to Medium Armor
B) Gets a free feat
C) Doesn't have DEX as their primary stat
D) Still manages to have a 16 DEX despite having no plans to raise it from there
E) Wants to be adequate at Stealth.

Such as perhaps a CHA-based Hexblade or WIS-based caster Cleric who happened to rolled moderately well on DEX and wants to be able to sneak.

[Mastikator]

As a free feat (no ASI alternative available), I agree that its value improves, especially at early levels.

Medium Armor Master is typically examined in the context of an ASI. By the time your first ASI rolls around at Level 4, basically any DEX-based character will have access to Studded Leather, and 18 DEX with Studded Leather makes more sense than 16/17 DEX with MAM.

However, even as a first free feat, its value is limited in the long run on a DEX-based character. A DEX-based character will eventually want to have 20 DEX. And 20 DEX with Studded Leather is only 1 AC point less than 20 DEX with Half Plate and MAM. So you're effectively spending an entire feat on +1 AC, which isn't really worth it in the long run compared to all the greater benefits of so many other feats, although it may be worth it in Tier 1 while your DEX is lower (such as a low level one-shot, or a campaign that's going to end at early levels).

In the long run, it's only really useful for niche builds, like a PC who doesn't have DEX as their primary stat, but still manages to have a 16 DEX despite having no plans to raise it from there, and who still wants to be adequate at Stealth. Such as a CHA-based Hexblade, or WIS-based Cleric.

Could just let him re-spec at level 4. Replace MAM with tough or piercer or something. Piercer is fun because it lets you reroll low damage rolls once per turn.

[JackPhoenix]

The only issue with MAM is that it's not a half-feat (+1 Str or Dex), as it should be.

[Mastikator]

On the other hand, who cares that it's not fully optimized?

[Unoriginal]

So, my 8 year old nephew has discovered my brother's old TSE-era D&D books and became fascinated by them. So much that I decided to gift him the PHB in our native language. 1st thing he said, after screaming with delight, was "I've got to make my character"

So I decided to help him, asked him first what race he wanted to be: human. Ok, now let's read the brief class descriptions, what do you want to be? A Ranger. Ok, we've rolled the dice and he got a lot of even rolls, so I decided to make a V. Human, and then at the end just choose a feat for him

Having finished making his character, went to take a look at the PHB feats, and realized how at once simple and effective getting Medium Armor Master would be. My nephew told me he wanted to be good at sneaking, so he'd chosen the leather armor, giving him 14 AC. But if he got Medium Armor Master and Scale Mail, he'd have 17 AC and still be good at sneaking.

So, +3 to his AC, and he doesn't even need to think about it or understand complicated mechanics. It's absolutely true that other feats could be more effective, but I don't think any other could be at once this effective at his current level 1 and also this simple to use, just put the proper number on your sheet and you're done.

What do you guys think? Good idea? Some other suggestion that would be simple enough for an 8 year old kid who's making his first character? My other choice was alert-definitely a better feat, and simple enough, but one that would require him to remember and understand more game rules.

Does your nephew prefers the aesthetic/cool factor of wearing leather armor, or the aesthetic/cool factor of wearing scale mail, for the character he has in mind?

That's the only concern to have, IMO, since your nephew is trying to create the character he imagined.

If he thinks scale armor is cool as heck but didn't want it because it's not sneaky, then Medium Armor Master is the feat for that character.

[Pex]

On the other hand, who cares that it's not fully optimized?

This.

I optimize. I don't apologize for it. Many times I've seen players make choices I never would. For the most part they work. I will cringe at the 10 CO characters and the characters with less than 16 in their prime even after level 4, but it's not my character. The game math matters, so I can't help but hope they eventually learn to care about the game math a bit more. As long as they're not donkey cavities then I have learned to get over it their not optimal character.

As for the PC in question, maybe/maybe not the child will be bothered when his DX is 18/20 at higher levels his AC does not increase. He'll like the bonus to hit and damage. It can also be emphasized when it's night time and he's not sleeping in his armor, should something happen that 18/20 DX to his unarmored AC does come in handy so not wearing armor isn't as much a feels bad as it could have been. Then again, maybe he won't be in a rush for 18/20 DX. He'll pump another stat or take more feats. He might even want Sharpshooter not for the -5/+10 but to ignore cover. He'll enjoy beating the DM when he can say he shoots at the orc standing behind a short wall, and the orc receives no benefit from it.

[RogueJK]

The only issue with MAM is that it's not a half-feat (+1 Str or Dex), as it should be.

I agree that this would nudge MAM from "almost never worth it" to "sometimes worth possibly considering".

[Sigreid]

Medium Armor Master is a solid feat for character concepts that want to wear medium armor and be stealthy. It's really a great feat for a ranger that wants to mix it up in melee and scout.

[Kane0]

Youre right, its a decent pick if you dont want additional cognitive load.
I'd still make it a half feat though.

[firelistener]

It sounds like you're being a wonderful uncle! Since he's playing Ranger, Dual Wielder might be a good option as well, if he intends to use the Two-Weapon Fighting style. Many of my adult players imagine their characters wielding twin longswords or rapiers and get frustrated to find out they need to stick with light weapons, so maybe your nephew is thinking the same thing.

[Tanarii]

It's a good feat for anyone that starts with Medium armor, is planning to cap at Dex 16, has a spare ASI (or free feat from Variant Human) and wants to sneak. Also passable for someone in Medium armor, wants +1AC and to still be passable at sneaking and has a Dex 14 but wont raise it.

Mostly that means StRangers, Str Valor Bards, Str Mtn Dwarf Warlocks, and some Clerics. And Hexblades if those are allowed. It would include Barbarians except their ASIs are typically spoken for with maxing Str/Con and picking up GWM, or even short one.

Of course, if you're cool with not maxing your primary attack stat (especially if not playing up to lvl 19), the entire consideration can change. Then it's usually just "do I raise my attack stat, con, or get +1AC and still be able to sneak?"

Also opening up which found magic items you can use might be a consideration. Although magic armor in general is pretty rare to find until considerably later on. Edit: For example, your chance of finding a +1 Chain Shirt before level 11 is tiny (roughly 1% chance). Finding +1 chain or splint is double that. Still minuscule but it basically triples the chance of finding magic armor you can use eventually. As well as most likely putting it in less demand, depending on party make up.

[Leon]

Almost all the feats are decent if they do what You want them to no matter your level of player experience

[Pex]

It's a good feat for anyone that starts with Medium armor, is planning to cap at Dex 16, has a spare ASI (or free feat from Variant Human) and wants to sneak. Also passable for someone in Medium armor, wants +1AC and to still be passable at sneaking and has a Dex 14 but wont raise it.

Mostly that means StRangers, Str Valor Bards, Str Mtn Dwarf Warlocks, and some Clerics. And Hexblades if those are allowed. It would include Barbarians except their ASIs are typically spoken for with maxing Str/Con and picking up GWM, or even short one.

Of course, if you're cool with not maxing your primary attack stat (especially if not playing up to lvl 19), the entire consideration can change. Then it's usually just "do I raise my attack stat, con, or get +1AC and still be able to sneak?"

Also opening up which found magic items you can use might be a consideration. Although magic armor in general is pretty rare to find until considerably later on. Edit: For example, your chance of finding a +1 Chain Shirt before level 11 is tiny (roughly 1% chance). Finding +1 chain or splint is double that. Still minuscule but it basically triples the chance of finding magic armor you can use eventually. As well as most likely putting it in less demand, depending on party make up.

Magic items are DM discretion, not percentages. There is no guarantee any one particular magic item will appear other than DM say so, but no magic items exists or doesn't exist without DM permission. Treasure tables are a tool a DM can choose to use or not use as he sees fit. If he wants a PC to have magic armor the PC will have magic armor. It would be prudent for the DM in this case not to give out Mithral Armor for then that will cause a Feels Bad, unless the DM is willing to allow a retrain of the feat.

[Tanarii]

Magic items are DM discretion, not percentages.
Fine. Pretend my edit atarts with: Assuming the DM uses the Treasure tables as suggested in the DMG ...

[Pixel_Kitsune]

A feat can be great for an idea or build without being "optimal" and still be powerful. Have a character that was a Hexblade/Paladin mechanically and optimally I do not really want Dex at all, just go Full Plate. But I gave them a thief ish background and wanted Stealth and such, so Medium Armor Master and Dex 16 meant I could be good at those skills and still play the Knight in Shining Armor.

[sithlordnergal]

I dunno...I tend to find MAM pretty handy for very specific builds that can't get Heavy Armor, and where maxing out Dex is a waste of ASIs. So certain Bards, Hexblades, Clerics, Druids, and the like. I never waste ASIs on maxing out Dex unless its used as my primary attack stat, opting for Feats instead. Though if I can just use Heavy Armor, I'll opt to do that instead, even if I don't meet the strength requirements since a -10 to speed isn't exactly a problem.

[animewatcha]

I would say that eventually him getting half-plate while still medium can work. Afterall, the level is threat is 'gettign stronger' and his character is gonna need better defense to fall back on when the going gets rough. Maybe I missed something but was the fighting style mentioned of what he wanted to do. 2hander (like lots of anime-cartoon protags) or a 1handed free-hand type, or sword and board?

[Martin Greywolf]

What do you guys think? Good idea? Some other suggestion that would be simple enough for an 8 year old kid who's making his first character? My other choice was alert-definitely a better feat, and simple enough, but one that would require him to remember and understand more game rules.

Sigh. As someone who both interacted with several 8-year-olds and has some reading comprehension...

It depends. The age of your nephew is the one where you see a lot of differences, some kids can just about handle the algebra and fairly complex rules interactions of a TTRPG, some will have trouble for a few years. It all boils down to the whole "an adult can remember 7 things at once, plus or minus two, kids and old people start at 5 or 6".

Unless you know him really well and know he is the specific kind of nerd to want all the numbers and fiddly bits (as I once was, though possibly not at 8), my advice is to start slow and let him respec, possibly after every session. Start with feats that have little to no mental upkeep and go from there.

From that standpoint, yeah, all the armor proficiency feats are great, they do something and don't make you keep them in mind all the time to benefit from them. This is also the exact thing that makes them boring once you have the handle on the game, because as neat as more AC is, Polearm Master lets me actually do more things.

[IsaacsAlterEgo]

I'm playing a Battlesmith Artificer right now who started with MAM and I'm finding it useful enough. Having to start with 16 dex was a big ask, but it means at level 3 I'm able to hit 20AC and I can still sneak around just as effectively as anyone else in the party, so I'm not holding the group back with group stealth checks when we decide to go that route. I could have just gone with the heavy armor feat, but heavy armor tends to be much harder to access than medium, Dex tends to be a better stat to invest heavily in than strength, and my teammates seem to appreciate me not botching stealth checks all the time.

[KorvinStarmast]

Having finished making his character, went to take a look at the PHB feats, and realized how at once simple and effective getting Medium Armor Master would be. My nephew told me he wanted to be good at sneaking, so he'd chosen the leather armor, giving him 14 AC. But if he got Medium Armor Master and Scale Mail, he'd have 17 AC and still be good at sneaking.

So, +3 to his AC, and he doesn't even need to think about it or understand complicated mechanics.
I explicitly built my Ranger for Tomb of Annihilation with vHuman Medium Armor Master feat.
Works great. :smallsmile:

My Watcher paladin in Phoenix's game did also. Works great. :smallsmile: He likes to be sneaky.

For Jack: The archery fighting style has a sweet, flat +2 attack mod.
Bounded accuracy takes care of to hit probability in melee.
Half plate with shield and Med Armor Mastery, when he can afford Half Plate (400 GP) does well enough.
And no disadvantage to sneak. Take stealth proficiency, and to go a bit Optimized, become a Gloom Stalker at level 3.

[Dr.Samurai]

I have Medium Armor Master on my V Human Wild Soul Barbarian. I'm at 20 AC with a shield, and am pretty decent at Stealth when needed. Having 16 Dexterity also synergizes well with Danger Sense and Feral Instinct, so I'm happy with it.

[Jophiel]

Does your nephew prefers the aesthetic/cool factor of wearing leather armor, or the aesthetic/cool factor of wearing scale mail, for the character he has in mind?
You can just call the scale mail "Thick leather" or "Reinforced leather" or something similar if it really matters. I think many people divorce their sheet mechanics from their head canon anyway.

[Tanarii]

You can just call the scale mail "Thick leather" or "Reinforced leather" or something similar if it really matters. I think many people divorce their sheet mechanics from their head canon anyway.
Those things already exist. They are called Padded, Leather, and Studded Leather.

You can't just "refluff" something that has rules into something else that already has rules.

Not that this counts as refluffing anyway. Removing the metal from the armor has possible impact.

[Kurt Kurageous]

Helping a new and young player make a more effective character is very nice. This new player seems eager just to be part of the game, and is not gunning for GOAT.

So get him in the game. You already rolled dice, so 'tis possible his character has already overcome the scores others have assumed possible with point buy or standard array.

Kid's got stars in his eyes. Enjoy it. In five short years he will be a teenager, and with your encouragement probably running games for his friends.

[JNAProductions]

Those things already exist. They are called Padded, Leather, and Studded Leather.

You can't just "refluff" something that has rules into something else that already has rules.

Not that this counts as refluffing anyway. Removing the metal from the armor has possible impact.

Removing the metal matters only for Druids. And only if you follow that dumb line in the proficiencies section, which I certainly don't care about as a DM.

As for refluffing... So long as everyone knows what's what and is on board with it, even if something else could be used for it, it's not a big deal.

Finally, this is a youngster's first game. The priority should NOT be RAW-accuracy. It should be having a good time. (I mean, that's true in general, but ESPECIALLY in this situation!)

[Nidgit]

It's decent for any MAD class that plans to cap Dex at 16 and wants to sneak. The means Valor Bards, Dex Paladins, Dex Clerics, Spores Druids, Artificers, and Hexblades. Maybe a few others too I'm not thinking of.

[JackPhoenix]

Removing the metal matters only for Druids. And only if you follow that dumb line in the proficiencies section, which I certainly don't care about as a DM.

As for refluffing... So long as everyone knows what's what and is on board with it, even if something else could be used for it, it's not a big deal.

Finally, this is a youngster's first game. The priority should NOT be RAW-accuracy. It should be having a good time. (I mean, that's true in general, but ESPECIALLY in this situation!)

Heat Metal says hi. As do Shocking Grasp, rust monsters, and few other effects.

[JNAProductions]

Heat Metal says hi. As do Shocking Grasp, rust monsters, and few other effects.

Fair. I did forget those. I don’t think having Medium-tier armor without metal is anything to worry about, though-maybe apply a bit of a surcharge on it, but that’s about all I’d do if I was concerned.

[strangebloke]

From a purely mechanical perspective, non-metal halfplate or whatever would at best be a common magic item. Magically treated leather or something.

There's no reason to make this such a sticking point if its a dealbreaker for someone.

[diplomancer]

Helping a new and young player make a more effective character is very nice. This new player seems eager just to be part of the game, and is not gunning for GOAT.

So get him in the game. You already rolled dice, so 'tis possible his character has already overcome the scores others have assumed possible with point buy or standard array.

Kid's got stars in his eyes. Enjoy it. In five short years he will be a teenager, and with your encouragement probably running games for his friends.

He rolled slightly worse than Standard Array; 15, 14, 12, 12, 12, 7. Nothing terrible, though, so might as well start teaching him to accept the luck of the dice and embrace his weak points as Roleplaying opportunities.

[Jophiel]

Those things already exist. They are called Padded, Leather, and Studded Leather.

You can't just "refluff" something that has rules into something else that already has rules.

Not that this counts as refluffing anyway. Removing the metal from the armor has possible impact.
You're over thinking it. Kid wants a dude dressed in leather. Refluff splint as a medium class leather armor (with a metal component reinforcing it if you're worried about Heat Metal). Call it whatever. Done.

The fact that "studded leather exists" is irrelevant. Studded leather isn't a medium class armor with the stats of splint. This will be. It's literally just splint that looks like leather with a fluffed name so the kid feels like he's wearing leather but mechanically benefiting from splint.

Point being that someone wanting their guy to look like he's wearing leather not only isn't an insurmountable obstacle to wearing medium, it shouldn't be an obstacle at all. Use your imagination.

[Tanarii]

As for refluffing... So long as everyone knows what's what and is on board with it, even if something else could be used for it, it's not a big deal.


You're over thinking it. Kid wants a dude dressed in leather. Refluff splint as a medium class leather armor (with a metal component reinforcing it if you're worried about Heat Metal). Call it whatever. Done.

I am not overthinking it. House rule away as needed, but be aware of the impact if you're making leather armor work like a medium armor. It's not refluffing, and it has in world implications if you house rule one thing to be another that already exists.

For example, you need to decide what happens if the character's armor is destroyed or they find magical studded/leather. Do they get to pick up leather armor and wear it as medium armor or not? What if they take off their armor and give it to another character? Does it work as leather or medium armor?

In this case, probably the best house rule would be a character specific ability that lets them use light armor as the corresponding medium armor instead.

[Pixel_Kitsune]

Not to mention that the PHB flat out says refluff whatever you want so long as it doesn't change the mechanics.

I have multiple characters that are wielding "shields" that take up their offhand, cost a certain amount of gold and have a certain weight.

They consist of an armored sleeve, a hammer, a reinforced scabbard, a... you get the idea.

[Dr.Samurai]

I think Tanarii has the right of it. The line between refluffing and straight up changing mechanics can be blurry. In this case, being made of metal makes a difference.

Similarly, gold cost and weight are fine, but it takes an action to don a shield. So as long as it takes an action to wield that armored scabbard, should be fine.

[Kane0]

Brigandine. Leather armor with metal reinforcement underneath.

[Pixel_Kitsune]

Brigandine. Leather armor with metal reinforcement underneath.

Specially considering the difference between Splint Mail and Bridandine IRL is literally rather or not the metal is visible on the top layer.

So, here's a fun IRL "reflavor" thing. I've fought in the SCA and I've seen people go about armor two ways (to massively generalize). One is to have plate on the outside, obvious metal and armor. The other is to make it out of something even better, like Kydex, and wearing it under tunics, tabbards, etc.

I've been "Fully" armored while appearing to be in anything from simple clothes to a noble's coat to a dress.


Similarly, gold cost and weight are fine, but it takes an action to don a shield. So as long as it takes an action to wield that armored scabbard, should be fine.

I said no change to mechanics, that would include the action to don. But in the same breath, I often don't stress that with real shields either.

[Jophiel]

I am not overthinking it. House rule away as needed, but be aware of the impact if you're making leather armor work like a medium armor. It's not refluffing, and it has in world implications if you house rule one thing to be another that already exists.
"Reinforced Leather" is not in the PHB. Leather armor is and studded leather is. "Reinforced Leather" is not. You're not turning "Leather Armor" into a medium class armor, you're grabbing a suit of Splint and putting a Post-It note on it saying "Reinforced Leather".


For example, you need to decide what happens if the character's armor is destroyed or they find magical studded/leather. Do they get to pick up leather armor and wear it as medium armor or not? What if they take off their armor and give it to another character? Does it work as leather or medium armor?
This is what I meant by overthinking it. If someone said "Black armor is cool" and you said the character could have Black Splint, would you be worrying about what unknowable things happen when the character puts on a suit of padded armor instead or gives his armor to the cleric? No, because nothing happens except now the cleric is wearing swanky black armor. That's the only thing happening here -- someone thinks armor made of leather (NOT PHB "Leather Armor") is awesome so he gets a suit of (mechanically) Splint except it has leather paint on it. This is literally the basest version of refluffing, no different from casting purple fireballs.

[Tanarii]

"Reinforced Leather" is not in the PHB.
Yes it is. It is called Studded Leather.

[Kane0]

Yes it is. It is called Studded Leather.

Oh man, studded leather is a fun discussion.

[Jophiel]

Yes it is. It is called Studded Leather.

No, Studded Leather is Studded Leather. The description might involve reinforcement but "Reinforced Leather" is not in the PHB.

Or call it some other sort of "leather". I have no clue why you're making this so incredibly obtuse for no good reason. Are you this worried about there being multiple armors of multiple types made out of metal? Heck, there's already Hide Armor listed under Medium which is made out of animal skin and the game hasn't broken down yet. So, hey, Reinforced Hide Armor -- looks like leather, works like Splint. And no "Studded Hide" to get worried about.

[Tanarii]

No, Studded Leather is Studded Leather. The description might involve reinforcement but "Reinforced Leather" is not in the PHB.PHB 144.

Studded Leather. Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.

You don't get to claim it's not in the PHB because reinforced leather doesn't have a label/name "reinforced leather". That's not how rules definitions work.

It's the equivalent of selecting Firebolt as a cantrip, renaming it Ball of Fire, and the replacing its rules with the Fireball rules.

[Pixel_Kitsune]

PHB 144.

Studded Leather. Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.

You don't get to claim it's not in the PHB because reinforced leather doesn't have a label/name "reinforced leather". That's not how rules definitions work.

It's the equivalent of selecting Firebolt as a cantrip, renaming it Ball of Fire, and the replacing its rules with the Fireball rules.

Cool, so, fun fact... If, instead, we use leather reinforced with metal plates instead of rivets, or carapace from a creature, or we take the fact that studded leather is for some reason NOT treated and hardened leather like leather is and so combine the hardened leather with reinforcement.

OR... You take a suit of whichever armor you want and put a layer of leather over it for flavor and move on.

Honestly, what is your argument here? As for your cantrip analogy, no. It would be like if you were making a full on water themed mage selected the firebolt cantrip and reflavored it as a burst of steam rising up from beneath the target while still being a ranged spell attack that does 1d10 fire damage.

[Jophiel]

PHB 144.

Studded Leather. Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.

You don't get to claim it's not in the PHB because reinforced leather doesn't have a label/name "reinforced leather". That's not how rules definitions work.

It's the equivalent of selecting Firebolt as a cantrip, renaming it Ball of Fire, and the replacing its rules with the Fireball rules.

This argument is inane but it doesn't matter. Super-Duper-Reinforced-Non-Studded Leather. Done.

[JNAProductions]

PHB 144.

Studded Leather. Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.

You don't get to claim it's not in the PHB because reinforced leather doesn't have a label/name "reinforced leather". That's not how rules definitions work.

It's the equivalent of selecting Firebolt as a cantrip, renaming it Ball of Fire, and the replacing its rules with the Fireball rules.

It's not. Not at all.

How much does this Reinforced Leather Armor cost? 750 GP.
How much does it weigh? 40 lbs.
What AC does it give? 15+Dex Mod (Max 2 without MAM, 3 with it).
What does it do to Stealth rolls? Disadvantage, unless you have MAM.

In your example, you're massively altering the mechanics.
In the example that's pertinent to the thread, the mechanics are identical-only the looks are changed.

[Witty Username]

I like Medium Armor Master, it is a good bump in AC for dex builds in early levels, expands loot options, and a good option for diversified stat lines (such as cleric and hexblade).
I have no problems recommending it.

[da newt]

Ask the kid which he prefers.

Personally I'd include the option of SS (and Archery FS) vs MAM vs Alert vs revenant blade (and waive the elf requirement - it's just cool and might be perfect for the little dude)

I'd also explain the options of leather, studded leather, breast plate, etc too.

Let the kid choose (unless he tells you to choose for him).

I'll also throw out, if a PC wears 1/2 plate they can doff the extra bits to go breast plate and stealth at any time. It only takes 1 minute to doff med armor, 30 seconds if another PC helps, and (if the DM allows) even less time because you aren't doffing the breast plate, just the other bits ...