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.
Starting at 3rd level, you always have certain spells prepared after you reach particular levels in this class, as shown in the Armorer Spells table. These spells count as artificer spells for you, but they don't count against the number of artificer spells you prepare.
Armorer Spells, Artificer Level
3rd: Magic Missile, Thunderwave
5th: Mirror Image, Shatter
9th: Hypnotic Pattern, Lightning Bolt
13th: Fire Shield, Greater Invisibility
17th: Passwall, Wall of Force
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.
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 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. As a bonus action, you can 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. You can use this bonus action a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
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 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.
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.
Starting at 5th level, you can attack twice, rather than once, whenever you take the Attack action on your turn.
At 9th level, you learn how to use your artificer infusions to specially modify your Arcane 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 Arcane Armor.
At 15th level, your Arcane Armor gains additional benefits based on its model, as shown below.
Guardian. When a Huge or smaller creature you can see ends its turn within 30 feet of you, you can use your reaction to magically force the creature to make a Strength saving throw against your spell save DC, pulling the creature up to 30 feet toward you to an unoccupied space. If you pull the target to a space within 5 feet of you, you can make a melee weapon attack against it as part of this reaction.
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. Any creature that takes lightning damage from your Lightning Launcher glimmers with magical light until the start of your next turn. The glimmering creature sheds dim light in a 5-foot radius, and it has disadvantage on attack rolls against you, as the light jolts it if it attacks you. In addition, the next attack roll against it has advantage, and if that attack hits, the target takes an extra 1d6 lightning damage.
Legendary Sub-class
Increase Modifications
Prerequisite: 21st level
Guardian: Harmonic Burst: When a creature affected by your thunder gauntlets targets a creature other than you with an attack, it takes 2d8 + your Intelligence modifier thunder damage as the pulse explodes with power. You can only deal this damage once per turn. Additionally, the damage of your thunder gauntlets increases to 2d8
Infiltrator: Electric Ghost: Any creature that takes lightning damage from your Lightning Launcher glimmers with magical light until the start of your next turn. The glimmering creature sheds dim light in a 5-foot radius, and it has disadvantage on attack rolls against you, as the light jolts it if it attacks you. In addition, the next attack roll against it has advantage, and if that attack hits, the target takes an extra 1d10 lightning damage
Manipulator Armor
Prerequisite: 21st level
Remote Limb. You attach two additional limbs onto the armor. They have a reach of 20 feet and can hold a number of pounds equal to 10 times your Intelligence modifier. You can use them as weapons, and they deal 1d8 bludgeoning damage on hit. Once per turn you hit a creature of large size or smaller with a limb, you can attempt to grapple it, using your Intelligence modifier, instead of your strength modifier for the roll.
All Terrain Movement. You have a climbing speed equal to your walking speed. In addition, you can move up, down, and across vertical surfaces and upside down along ceilings, while leaving your hands free.
Metallic Kraken. You construct an additional remote limb onto your armor. Your remote limb deals an additional 1d8 damage. Additionally, when hit a creature of large size or smaller with the limb, you can move it 10 feet in any direction of your choice.
Destructor Armor
Prerequisite: 23rd level
Titanic Fists. Each of the armor's gauntlets counts as a simple melee weapon while you aren't holding anything in it, and it deals 1d10 bludgeoning damage on a hit, and an additional 1d4 if you are grappling the target. When you hit a creature with this weapon, you can grapple it as a bonus action.
Powerful Build. You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.
Artificial Strength. Whenever you make a strength check, you can use your Intelligence modifier, instead of your strength modifier, and attacks you make with your titanic fists deal double damage to objects and structures.
Steel Plated Giant. You can cast enlarge/reduce on yourself at will without expending a spell slot, but only the enlarge option. When cast this way, it does not require concentration and it lasts until dispelled. Additionally, any creature that starts it's turn grappled by you takes the damage of your Titanic Fists automatically
1st Armor Model Perfected
Prerequisite: 25th level
You now have double effects for the Guardian Armor and the Infiltrator Armor. The only not affected thing is the ADV/DISADV
2nd Armor Model Perfected
Prerequisite: 27th level
You now have double effects for the Manipulator Armor and the Destructor Armor. The only not affected thing is the ADV/DISADV
Phase Armor
Prerequisite: 30th level
As a bonus action you will be able to change between different Armors