What happens when you wear armor you’re not proficient in?

What penalties or restrictions does a creature have when they don armor they’re non proficient in?

For example, picture a newly adventurous (level 1) Dwarf Barbarian (18 Strength, 10 Dexterity) who has inherited a set of Full Plate armor. He’s only Trained up to Medium Armor, but he feels obligated to don it. What are the results? What if he still wears this armor at level 10 (assuming he never takes the Armor Proficiency Feat)?

This is generally a question to clarify related rules, but it has the possibility to come up. For instance, said Barbarian may invest in Feats that give benefits when hit or critically hit. Additionally, you could ‘equip’ the enemy Wizard you’ve captured to add to your restraints.

Does a Tortle’s Natural Armor interfere with the Monk’s Unarmored Movement ability?

The Tortle’s Natural Armor ability says:

Due to your shell and the shape of your body, you are ill-suited to wearing armor. Your shell provides ample protection, however; it gives you a base AC of 17 (your Dexterity modifier doesn’t affect this number). You gain no benefit from wearing armor, but if you are using a shield, you can apply the shield’s bonus as normal.

The Monk’s Unarmored Movement ability says:

Starting at 2nd level, your speed increases by 10 feet while you are not wearing armor or wielding a shield. This bonus increases when you reach certain monk levels, as shown in the Monk table.

The comments on this answer to a related question briefly mention the interaction between Natural Armor and Unarmored Movement, but nothing conclusive is discussed.

It is not clear if Natural Armor counts as worn, or even as armor, for the purposes of the Monk’s Unarmored Movement Ability.

Does a Tortle’s Natural Armor interfere with the Monk’s Unarmored Movement ability?

How much gold and how much time does fitted mithril or adamantine armor cost in D&D 5e?

I’m looking for the most widely accepted rules for buying mithril and adamantine armor, including chain, splint, half and full plate. How much gold and how much time for a merchant to craft does each piece of armor listed (8 total) cost, baseline? Non official rules are allowed as long as they are widely used. I’ve scoured many sources like the DMG, in addition to the other official 5e sources.

How to explain to AD&D player that items that increase Armor Class in DnD5e are overpowered?

Context: I have recently started a campaign with a new player that comes from AD&D background. He wishes to convert and import his character to the campaign. We do that once, I help him with the conversion and checked his stuff, he got 2 magical items lvl3 a bit much but I didn’t mind they were not game-breaking (ring of immunity to poison and mobility boots(longer jumps and a bit of speed up)? His character died, He asked to bring another character this time I let him do, I ask him for his stuff and he says that he has a magical sword and a giant strength belt (lvl6) this is IMO very strong, but again not game-breaking I tweaked a bit the encounter and it went fine.

The thing is that I give him a full plate armour and then he says that his armour class was 23. I was surprised because Max AC without magic is 20 – 21 (with defence combat style (which he has)). So I asked how His sword is :

The Items magical sword +2 attack bonus, magical damage, +2 fire damage, +2 AC.

IMO At this level having a CA of 23 (25 with "shield of faith" he plays a paladin) is game-breaking most monster exception the strongest get attack bonus of +4 +6, Meaning that he will only get hit on crit by most monsters, or that I have to send powerful monsters (that is maybe not fine for other players). The first question is that True? is this AC game-breaking at level 6?

I started to talk about this. and it went bad. He says that it is only 8 % increase of AC and did do much and that he gains his sword on a very deadly quest etc…. Maybe it is a good computation in AD&D setting but in 5e I feel it is not. Does it exist any rational arguments about this?

For now, I come up with the following arguments:

  • AC doesn’t scale the same, and 21 is already the maximum you should expect to be. A venerable red dragon AC is 22.
  • AC increase is extremely costly, with non-magical means they are only two ways: combat style and feats (heavier armour type or the Medium Armor Master feats (+3 dex))

Does there are other arguments? Or maybe I wrong?

D&D Armor Class?

So I’m very new to Dungeons and Dragons and need some help. I’m a sorcerer and there are some spells that require a saving throw from the DM. For example, a spell requires a Dexterity saving throw of 15. If the DM rolls a 11, does that mean they fail? If the number they roll is lower than the saving throw requirement, do they fail? If it’s over, do they succeed?

In the same type of question, I have an armor class of 11. When the DM rolls and asks if a 12 "hits", do I say yes? If the number is higher than my armor class, does it hit? If it’s lower than 11, it fails?

Thank you

Can multiple types of armor be stacked?

A character in my ongoing Exalted 2e game has an artifact chain shirt. Artifact chain shirts are described as being able to be worn under ordinary clothing (it has no mobility penalty or fatigue value). He’s also recently acquired a (non-artifact) reinforced breastplate. He’d like to wear them both. I don’t see any rules describing whether this can be done, what net protective effect it would have, or what effect it would have on mobility and fatigue.

Can multiple types of armor be stacked? How would I adjudicate this?

The character in question is pretty fragile so I’m not entirely opposed to his getting some kind of benefit, but I worry about setting a precedent that will bite me later.

How can I gain resistance to piercing, bludgeoning, and slashing damage while in heavy armor?

I am theory-crafting a character that takes very little damage. I want to use the Heavy Armor Master feat to help with damage reduction from non-magical attacks, as well as the Battlemaster maneuver parry, and the Goliath feature stone’s endurance. How can I gain resistance to piercing, bludgeoning, and slashing while also using the Heavy Armor Master feat? I am most interested in answers that don’t depend on external sources, such as other characters and magic items, but I’d like to hear answers including those as well. Multi-classing is an option.

Can Touch Range Spells/Effects Function Through Armor?

I am planning on playing a Grung PC for an upcoming homebrew campaign. The Poisonous Skin feature in Grung racial traits state:

Any creature that grapples you or otherwise comes into direct contact with your skin must succeed on a DC 12 Constitution saving throw or become poisoned for 1 minute. (One Grung Above p.4)

Now, this would be a problem if I wanted to support my party. (ie. Touch range spells) Would coming "into direct contact with your skin" mean skin on skin contact, or would the poison affect still work on skin and armor contact? Furthermore, is this the same deal with touch range spells? I guess I’m trying to find out: Can I, as a Grung, cast a touch range spell, like Cure Wounds, and bypass the poison effects by specifying that I touch the target’s armor? I’m not worried about enemies, because they are enemies, but more for my fellow party member’s sake.