Requires Iron Heart race. An artificer who specializes as an Arc Armorer modifies armor to function as an extension to their Infernal Arc. 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.

Tools of the Trade

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.

Arc Power: Scorching Ray

Gain an Arc Power charge. Gain an additional charge at levels 5, 9, 13, and 17. Arc Powers require a charge to cast. Regain expended charges after a long rest. Gain Arc Spell (Scorching Ray)

Arc 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 Arc 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 arc 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 Arc Armor until you don another suit of armor or you die.

Armor Model

Beginning at 3rd level, you can customize your Arc 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 use your Intelligence modifier, instead of Strength or Dexterity, for the attack and damage rolls. You can change your Arc 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 frontline of conflict. It has the following features:

Thunder Gauntlets. Your armored fists each count as a simple melee weapon, and each deals 1d8 thunder damage on a hit. A creature hit by the gauntlet has disadvantage on attack rolls against targets other than you until the start of your next turn, as the armor magically emits a distracting pulse when the creature attacks someone else.

Defensive Field. You gain a bonus action that you can use on each of your turns to gain temporary hit points equal to your level in this class, replacing any temporary hit points you already have. You lose these temporary hit points if you doff the armor.

Infiltrator

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

Lightning Launcher. A crystal lens appears on the palms of your gauntlets. It counts as a simple ranged weapon, with a normal range of 90 feet and a long range of 300 feet, and it deals 1d6 lightning damage on a hit. Once on each of your turns when you hit a creature with it, you can deal an extra 1d6 lightning damage to that target.

Powered Steps. Your walking speed increases by 5 feet.

Second Skin. The armor’s weight is negligible, and is able to retract under clothing. If the armor normally imposes disadvantage on Dexterity (Stealth) checks, the Arc Armor doesn’t.

Extra Attack

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

Arc Power: Fly

Beginning at 5th level, you can cast Arc Power: Fly using an Arc Power charge.

Armor Modifications

At 9th level, you learn how to use your artificer infusions to specially modify your Arc Armor. That armor now counts as separate items for the purposes of your Infuse Items feature: armor (the chest piece), boots, helmet, and the armor's special weapon. Each of those items can bear one of your infusions, and the infusions transfer over if you change your armor's model with the Armor Model feature. In addition, the maximum number of items you can infuse at once increases by 2, but those extra items must be part of your Arc Armor.

Perfected Armor

At 15th level, your Arc Armor gains additional benefits based on its model, as shown below.

Guardian. When a creature you can see ends its turn within 15 feet of you, you can use your reaction to cast Burning Hands without consuming a spell slot.

You can use this reaction a number of times equal to your proficiency bonus, and you regain all expended uses of it when you finish a long rest.

Infiltrator. Your Lightning Launcher now deals fire damage and does an additional 1d6 of damage.