An artificer who specializes as an Armorer modifies armor to function almost like a second skin. The armor is enhanced to hone the artificer's magic, unleash potent attacks, and generate a formidable defense. The artificer bonds with this armor, becoming one with it even as they experiment with it and refine its magical capabilities.

Tool Proficiencies

When you adopt this specialization at 3rd level, you gain proficiency with heavy armor. You also gain proficiency with smith's tools. If you already have this tool proficiency, you gain proficiency with one other type of artisan's tools of your choice.

Arcane Armor

Beginning at 3rd level, your metallurgical pursuits have led to you making armor a conduit for your magic. As an action, you can turn a suit of armor you are wearing into Arcane Armor, provided you have smith's tools in hand.

You gain the following benefits while wearing this armor:

• If the armor normally has a Strength requirement, the arcane armor lacks this requirement for you.

• You can use the arcane armor as a spellcasting focus for your artificer spells.

• The armor attaches to you and can’t be removed against your will. It also expands to cover your entire body, although you can retract or deploy the helmet as a bonus action. The armor replaces any missing limbs, functioning identically to a body part it is replacing.

• You can doff or don the armor as an action.

The armor continues to be Arcane Armor until you don another suit of armor or you die.

Armor Models

Beginning at 3rd level, you can customize your Arcane Armor. When you do so, choose one of the following armor models: Guardian or Infiltrator. The model you choose gives you special benefits while you wear it.

Each model includes a special weapon. When you attack with that weapon, you can add your Intelligence modifier, instead of Strength or Dexterity, to the attack and damage rolls.

You can change the armor's model whenever you finish a short or long rest, provided you have smith's tools in hand.

Guardian. You design your armor to be in the front line of conflict. It has the following features:

• Thunder Gauntlets. Each of the armor's gauntlets counts as a simple melee weapon while you aren't holding anything in it, and it deals 2d6 bludgeoning damage on a hit. 

• Defensive Field. As a reaction, you can generate a defensive field in response to any attack you receive. You must be able to see the attacker for this to work. Once you activate the field, you gain a +2 to AC and if the attack does not hit, the attacker is pushed 15 feet back by the field's expansion.

Infiltrator. You customize your armor for subtle undertakings. It has the following features:

• Lightning Launcher. A gemlike node appears on one of your armored fists or on the chest (your choice). It counts as a simple ranged weapon, with a normal range of 90 feet and a long range of 300 feet, and it deals 3d6 lightning damage on a hit. 

• Powered Steps. Your walking speed increases by 15 feet.

• Dampening Field. You have advantage on Dexterity (Stealth) checks. If the armor normally imposes disadvantage on such checks, the advantage and disadvantage cancel each other, as normal.

Extra attack

Starting at 5th level, you can attack twice, rather than once, whenever you take the Attack action on your turn.

Armor Modifications

At 9th level, your arcane armor becomes more potent. The results of such vary on the Armor Model you use.

Guardian. 

• The damage for your thunder gauntlets increases to 2d8 bludgeoning damage.

• The Defensive field now grants a +3 bonus to AC and can be used to deflect multiple attacks at once.

Infiltrator. 

• The damage from the lightning launcher increases to 5d6.

• The dampening field now imposes advantage on stealth checks regardless of if the armor would impose disadvantage.

• Any creature hit by the lightning launcher will be under the effects of the silence spell for the next minute. They will also shed dim light in a 5 foot radius that can be seen through walls as an outline.

Perfected Armor

At 15th level, you can now turn any armor into arcane armor after finishing a long rest, regardless of the wearer. The arcane armor also gains additional benefits based on its model, as shown below.

Guardian.

• The damage done by thunder gauntlets increases to 2d10 bludgeoning damage.

Infiltrator. 

• When you hit someone with the lightning launcher, all previous effects will happen against them but they will also have disadvantage on attack rolls and saving throws for the next minute

• Your speed increases by 30 feet while in the armor.

• You can no longer be targeted by divination spells short of those cast through wish