Main Walkthrough

By far the easiest Secondary Job that you can unlock, the Inventor Job also takes the longest to fully master. Each of its Skills requires you to hunt down a slew of items, and they will range from purchasable in stores to one-of-a-kind. You should nevertheless make the effort to get every Skill, as the Inventor Job can be useful for the entirety of Octopath Traveler II, all the way up to fighting the game's superboss.

A Genius Inventor

In order to unlock the Inventor Job you need to begin the A Genius Inventor Side Story. This is accomplished by traveling to the Eastern New Delsta Highroad, the first route outside New Delsta. Start the game as Throné and you can get the Job immediately after completing her first chapter.

Look for a house in the northeast once you're on the Highroad. It belongs to Arkar, an Inventor who plans to revolutionize the world - though apparently he won't even leave his home to look for supplies for creating his inventions. Agree to help Arkar in his ambitions and you'll begin A Genius Inventor, which unlocks the Inventor Job.

Once you help Arkar create all seven of his inventions he'll provide you with the eighth, the All-Purpose Tool. You'll also receive 10,000 leaves and a Mechanical Top Hat.

Inventor Skills

Arkar's home is filled with empty glass displays, each one representing an invention he plans to create once he has the proper supplies. Inspect one and you'll receive a small list of the required items. Bring them all back to Arkar and he will cobble them into an invention once you inspect the appropriate display case. This will unlock a Skill for the Inventor Job.

Inventor Skills don't work the same as any other Skills in Octopath Traveler II. Each of your Skills has a cooldown period whenever they're used, and you'll need to choose the Skill in the menu and use a turn to begin the cooldown process. The Hastening Hammer can reduce this cooldown on a Skill by one turn, but you need to have started the cooldown already for the Hastening Hammer to work.

There are two reasons Inventor Skills wind up being so powerful, despite the cooldown period:

  • They can be Boosted. In most cases this results in an effect being active for more rounds, which is decent on its own, but in the case of the Elemental Bomb Bottle it also results in multiple attacks on each elemental weakness. This can obliterate an enemy's shields.
  • They can be expanded to target every enemy or every ally. Agnea makes a fantastic Inventor thanks to her Latent Power, and Sealtigce's Seduction can give anyone else that same effect for several turns.

Unlike most Jobs, the Inventor Job unlocks Skills (including Passive Skills) for everyone in your party simultaneously. There's no need for JP expenditure, which makes the Inventor Job especially useful early on when you're still scraping together JP for each character's base Job.

Changeable Catapult

Effect: Target all foes with an attack of a weapon type of your choice
Cooldown: 1 turn
Materials Required: None - unlocked automatically

Springy Boots

Effect: Allows one ally to take their turn first for several rounds, starting with the next round
Cooldown: 2 turns
Materials Required: None - unlocked automatically

Critical Scope

Effect: All damage dealt to a single enemy is automatically critical for several rounds
Cooldown: 2 turns
Materials Required: 
  • Unerring Earring - New Delsta - Sold at the Armorer's shop in the west
  • Critical Earring - Canalbrine - Sold at the Armorer's shop in the north
Elemental Bomb Bottle

Effect: Inflict damage to each of an opponent's exposed elemental weak points 
Cooldown: 3 turns
Materials Required: 
  • Fire Soulstone - Found in NPC inventories and dropped by / stolen from Flame enemies
  • Ice Soulstone - Found in NPC inventories and dropped by / stolen from Ice enemies
  • Thunder Soulstone - Found in NPC inventories and dropped by / stolen from Thunder enemies
  • Rainbow Glass Bottle - Conning Creek - In a chest along the northwestern beach in the Outskirts
Tin Horn 

Effect: Fills the Latent Power gauges of all allies
Cooldown: 4 turns
Materials Required: 
Hastening Hammer

Effect: Inflicts damage on a single opponent and hastens the cooldown period of a Skill
Cooldown: 3 turns
Materials Required: 
  • Soldier's Bow - Clockbank - Purchased at the Armorer's shop in the northeast of the Industrial District
  • Guardian's Axe - Stormhail - Purchased at the Armorer's shop on the east side of town
  • Great Blade - Sai - Purchased at the Armorer's shop on the west side of town - Must scrutinize a Soldier in the east at night to unlock New Equipmen for Sale
Arkar's Coil

Effect: Restore 40% of an ally's HP and SP, grant them 1 BP, and revive the target if they have been knocked out
Cooldown: 7 turns
Materials Required: 
  • Scrap Metal - Clockbank - Acquired from a Factory Worker near the Armorer's shop, in the northeast of the Industrial District
  • Ancient Cog - Roque Island (town) - Acquired from a Factory Worker inside a house beside the Tavern
  • Natural Magnetite - Unfinished Tunnel - Inside a chest, through a hidden tunnel near the tracks that run through the dungeon

All-Purpose Tool

Effect: Trigger the cooldown period for every Skill that has already been used
Cooldown: None - can only be used with a level 3 Boost
Materials Required: None - unlocked once you complete every other invention

Main Walkthrough