How do you treat Mithral and Adamantine armor in your games?

[Coidzor]

They're listed in with the magic items yet don't seem to actually be magical themselves, just made out of exotic materials.

So how do you deal with them at your table? Super rare? Anyone with the tool proficiencies and materials can make them? Can't stack with other magical properties, such as being +1 or Mariner's Armor, unless it's some kind of unique item? Count as magical for purposes of adjudicating effects?

Can one have Mithral armor reinforced with Adamantine since one is what the armor is made out of and the other is reinforcement? Can one add in Adamantine reinforcement after the fact to modify an existing suit of armor?

[-Jynx-]

I've yet to try and introduce these into a campaign, but if it were me I'd probably say:

Mithril: Triples cost and adds an extra max dex to the armor (increasing medium armor from 2 to 3 and adding 1 to heavy)

Adamantine: +3000 to cost and gives -3 Damage reduction to non-magical attacks.

Cost is up to you, since the amount of gold you'd pass off in your campaign is DM dependant

edit: I probably wouldn't allow Mithril reinforced with adamantine since you'd lack the amount of metal during its reinforcement to give the full benefit of it. As far as rarity hmmm I'd probably just make the PCs have to find it, and just not introduce it until around level 8-9ish?

[Kane0]

For my table:

Mithril: Half weight, adds 1 to max dex bonus to AC, removes stealth disadvantage from armor
Adamantine: Turns crits into regular hits, reduce damage taken by 2

Both of these are in the rare category, using the DMG guidelines and adding that to the cost. That means most of my PCs won't be seeing or using it until level 10+.
I usually treat them as nonmagic and being enchantable, but usually their own benefits are good enough.

You can work them with smithing proficiency and special training (essentially a proficiency you have to train for, one each).

My most recent game actually had a mini-plot around these two materials, which at the end resulted in Mithantine alloy, an alchemically mixed combination taking the best traits of both, but at time of introduction that made it legendary category rare and expensive. Once the secret got out it would have gradually gone down to very rare status.



Can one have Mithral armor reinforced with Adamantine since one is what the armor is made out of and the other is reinforcement? Can one add in Adamantine reinforcement after the fact to modify an existing suit of armor?
It would make sense to have adamantine plating over mithril chain in your plate mail, but from a gamist perspective that would seriously unbalance things. But then again I have Mithantine for that.
You could even have your padding be dragon leather for a trifecta of supermaterials in your armor.

[Naanomi]

In my world both mining and forging those materials is akin to enchantment to begin with, so outside of legendary rarity and artifacts it is impossible to 'further' enchant them.

Furthermore both have a lot of utility as alloys for other metals (mixing adamantine with steel to strengthen a bank vault, mixing mithril in with silver for a string but thin 'elven jewlery' piece) so it is incredibly rare to 'waste' such materials in their pure form for armor or weapons

[JoeJ]

I don't like either of those materials, so in my world they simply aren't available. I leave Mithril in Middle Earth and say that Adamant (not Adamantine) is so hard that only certain gods can forge it. An object made of adamant will pretty much always be an artifact.

[Malifice]

Going by DMG precedent, Mithril armor grants proficiency, and Adamantine stops all crits.

You can also grant mithril weapons the light quality, and adamantine heavy if you want. Sounds about right.

[MeeposFire]

Going by DMG precedent, Mithril armor grants proficiency, and Adamantine stops all crits.

You can also grant mithril weapons the light quality, and adamantine heavy if you want. Sounds about right.

Lol heavy daggers that halflings cannot use without getting disadvantage and can be used with all aspects of the great weapon mastery feat (rather than just the crit function).

[Coidzor]

MeeposFire: That is one way to finally get to wield a greatsword without disadvantage as a halfling, though, assuming Heavy and Light cancel out. Otherwise that's a weapon which Small characters can't use without disadvantage that's also light enough to be suitable for TWFing despite being a two-hander.


edit: I probably wouldn't allow Mithril reinforced with adamantine since you'd lack the amount of metal during its reinforcement to give the full benefit of it. As far as rarity hmmm I'd probably just make the PCs have to find it, and just not introduce it until around level 8-9ish?


This suit of armor is reinforced with adamantine, one of the hardest substances in existence.

vs.


Mithral is a light, flexible metal.

For the descriptions of the armors on pages 150 and 182 respectively got my group to wondering about that. So Adamantine armor in your games is just made entirely out of adamantine the same way it was in earlier editions?


Going by DMG precedent, Mithril armor grants proficiency, and Adamantine stops all crits.

Did it get errata'd to do that or are you strengthening the benefits of mithral in a way you view as consistent with the theme of its RAW abilities?

...I should probably actually look at the errata soon...


For my table:

Mithril: Half weight, adds 1 to max dex bonus to AC, removes stealth disadvantage from armor
Adamantine: Turns crits into regular hits, reduce damage taken by 2

That's a nice boost to both, I believe it basically makes them each convey most of or all of the benefit of a feat in addition to what they'd already provided.


I usually treat them as nonmagic and being enchantable, but usually their own benefits are good enough.

I hadn't seen anything yet that indicated a character needed magic armor the same way a magic weapon is still necessary for dealing with many creatures in a timely manner, but I wasn't quite sure. So far all I've seen is the stuff about unattended magic items getting their own saves against certain damaging effect


You can work them with smithing proficiency and special training (essentially a proficiency you have to train for, one each).

Mundane crafting rate per day or magical?


My most recent game actually had a mini-plot around these two materials, which at the end resulted in Mithantine alloy, an alchemically mixed combination taking the best traits of both, but at time of introduction that made it legendary category rare and expensive. Once the secret got out it would have gradually gone down to very rare status.

So they're making some during downtime then? Or just discovered it and may be able to make use of the formula later on or give it to some smith NPCs?


It would make sense to have adamantine plating over mithril chain in your plate mail, but from a gamist perspective that would seriously unbalance things. But then again I have Mithantine for that.
You could even have your padding be dragon leather for a trifecta of supermaterials in your armor.

How so?

Does dragon leather do anything?

[Malifice]

Lol heavy daggers that halflings cannot use without getting disadvantage and can be used with all aspects of the great weapon mastery feat (rather than just the crit function).

Sounds amazingly funny.

Just pass off the cleave and extra damage as being.. you know... admantite.

[Malifice]

Did it get errata'd to do that or are you strengthening the benefits of mithral in a way you view as consistent with the theme of its RAW abilities?

Pretty sure Elven/ Mithril chain doesnt require you to be proficient.

Wizards can wear it and cast etc.

[JackPhoenix]

RAW:
Elven chain is a +1 chain shirt that can be used without penalty even if you aren't proficient in medium armor. No mention of it being made from mithral.

Mithral chain shirt can be worn under normal clothes, without any other benefit. You still need to be proficient to use it without penalty or to be able to cast spells while wearing it. Other mithral armors negate disadvantage on stealth check, but not the non-proficiency disadvantage on all other Dexterity or Strength checks, saves and attacks. RAW, they don't even weight less.

As written, it's kinda weird.

[Fwiffo86]

In my games they are considered magical for the following reasons:

Mithril - Does not occur naturally. It is a material that requires the harvesting of pure moonlight, and alloyed with Mercury. It is a process taught only to an extremely small sect of weapon smiths, who take only a single student. Ever.

Adamantine - Occurs naturally only from non-terrestrial sources (meteors, plane-shifted land masses). The proper mining techniques require ten times the effort and manpower. Forging requires at least triple the time and temperature. Only so many forges are built to accommodate the temperatures needed.

While technically "non" magical, the benefits from the materials are similar to others suggestions. Half the weight, increased dex mod for Mithril, damage reduction and resiliency for adamantine. The processes and effort required place them in the same category of magic items.

[Mudo]

RAW:
Elven chain is a +1 chain shirt that can be used without penalty even if you aren't proficient in medium armor. No mention of it being made from mithral.

Mithral chain shirt can be worn under normal clothes, without any other benefit. You still need to be proficient to use it without penalty or to be able to cast spells while wearing it. Other mithral armors negate disadvantage on stealth check, but not the non-proficiency disadvantage on all other Dexterity or Strength checks, saves and attacks. RAW, they don't even weight less.

As written, it's kinda weird.

Yes, agreed. The RAW seems like written in a hurry. My DM uses the strict variant encumbrance rule, so we "backported" the 3.5 mithral armor feature of having only half the listed weight.