Introduction

The Inventor’s Innovation feature serves double duty as both subclass and equipment, which makes sense considering what the Inventor does. Your choice of Innovation will greatly define your character’s tactics and role within the party.

Your choice of Innovation is a huge opportunity to opt into or out of complexity in your character. Armor is mostly passive, making it low complexity to build and low complexity to play. Construct is low complexity to build because so many of the decision points are essentially mandatory, but it’s high complexity to play because you’re managing a minion. Weapon is complex both to build and to play because Pathfinder 2e’s weapons are so intricate, and many of the modifications will add even more complexity to your Strikes by giving you new things to do with your weapon.

Disclaimer

RPGBOT uses the color coding scheme which has become common among Pathfinder build handbooks.

  • Red: Bad, useless options, or options which are extremely situational. Nearly never useful.
  • Orange: OK options, or useful options that only apply in rare circumstances. Useful sometimes.
  • Green: Good options. Useful often.
  • Blue: Fantastic options, often essential to the function of your character. Useful very frequently.

Innovations

Armor Innovation

The Armor Innovation offers the choice between the Power Suit (basically medium armor) and the Subterfuge Suit (light armor). Focusing on your armor offers access to passive skill bonuses and numerous damage resistance options, allowing you to be exceptionally durable for a class in medium armor with only 8+ hit points. However, it’s very easy to fall into the Tank Fallacy here since the Inventor isn’t quite so effective offensively as more conventional martial classes.

If you want to be tanky, Power Suit is a good choice. However, without a Reaction like Attack of Opportunity, you lack the “stickiness” that makes the Fighter an effective Defender, so your tactics need to be different. Expect to spend time blocking spaces, grappling, and otherwise making yourself a nuisance for your enemies.

If you want to be sneaky, Subterfuge Suit is the natural choice. Grab a ranged weapon or a finesse weapon, pick up Subtle Dampeners, and get sneaky.

Modifications

  • Harmonic OscillatorGG: The amount of resistance is good, but force and sonic damage are both extremely rare.
  • Metallic ReactanceGG: A good emount of resitance, and acid and electricity damage are both reasonably common.
  • Muscular Exoskeleton (Power Suit Only)GG: The bonus isn’t huge, but it’s consistent and easily accessible.
  • Otherworldly ProtectionGG: The amount is good, but the damage types are uncommon.
  • Phlogistonic RegulatorGG: You get 3 points less resistance than the options for other damage types, which should tell you how much more useful cold/fire resistance are compatred to other options.
  • Speed BoostersGG: A 5-foot bonus to speed doesn’t feel super impactful, but it can often be enough to Stride far enough away from an enemy that they either can’t reach you or need to make two Strides to do so. Of course, that’s provided that there is enough room for you to run directly away from a single enemy which doesn’t have ranged attacks and also your allies aren’t equally appealing targets for your enemy.
  • Subtle DampenersGG (Subterfuge Suit Only): The bonus isn’t huge, but it’s consistent and easily accessible.

Breakthrough Armor Modifications

  • Antimagic PlatingGG: The bonus is small and Circumstance bonuses are common, but it works consistently and doesn’t require you to do anything to activate it.
  • Camouflage Pigmentation (Subterfuge Suit Only)GG: Hide in plain sight.
  • Dense PlatingGG: Slashing damage is common in melee across the full level range, so this will mitigate a lot of damage throughout your career.
  • Enhanced ResistanceGG: Beware of diminishing returns. Small amounts of damage of various energy types can be common from things like weapon runes or cantrips, so a small amount of damage can significantly mitigate those threats. Adding even more resistance is great, but weigh the cost carefully. Investing too much in one group of resistances may not pay off.
  • Heavy Construction (Power Suit Only)GG: +1 to AC and add the Bulwark property so you’re getting a +3 dex bonus to Reflex saves rather than the +1 from your Dexterity. Sure, your Check Penalty goes up to -2, but you probably weren’t doing much sneaking anyway. This is a significant improvement to your durability.
  • Hyper BoostersGG: Only situationally useful. Running huge distances in combat doesn’t happen often, and if you’re traveling long distances you can get a horse.
  • Layered MeshGG: Piercing damage isn’t quite as common as slashing damage, but it’s still common, so this will certainly reduce a lot of damage.
  • Tensile AbsorptionGG: Of the three weapon damage types, bludgeoning is the least common because teeth and claws don’t deal bludgeoning damage. Dense Plating will almost certainly be more effective.

Revolutionary Armor Modifications

  • Automated ImpedimentsGG: This makes it very hard for enemies to get past you, and it may even prevent them from approaching you since you can’t Step into difficult terrain.
  • Energy BarrierGG: Broad and thorough protectin against almost everything except weapon damage.
  • Incredible ResistanceGG: Beward of over-investing in resistance to one type of damage. Consider Physical Protections instead.
  • Multisensory Mask (Subterfuge Suit Only)GG: An excellent defense, and it allows you to hide wherever you want, but in combat it’s rarely worh the Action to restore the field when you’re almost certainly going to use another hostile action.
  • Perfect Fortification (Power Suit Only)GG: A decent chance to reduce damage from critical hits. Resistance to precision damage is neat, but rarley impactful.
  • Physical ProtectionsGG: Good damage resistance to several of the most common damage tpyes in game.
  • Rune CapacityGG: Property runes offer a lot of great options, but they’ll rarely be as good as Physical Protection.

Construct Innovation

The most complex Innovation to play since you need to manage a second character constantly. The Construct Innovation is unique among minion features in that it allows you to give your Minion three Actions immediately, which typically requires a class feat for other characters like the Druid and the Ranger. Weirdly, Construct Innovation is also by far the easiest Inventor to build. There is an obvious feat choice at basically every level where you gain a Class Feat, so you rarely need to agonize over your build choices.

Repairing your construct is crucial to making it effective. Sure, every Inventor is going to maximize Craft, but you as the Inventor need to be able to use the Repair action to much greater effect because your construct’s continued existence depends on it. Expect to take feats like Quick Repair and Specialty Crafting.

Unfortunately, it’s unclear what the DC is to repair your companion. Unlike Treat Wounds which allows you to optionally, Repair’s effectiveness is multiplied based on your Proficiency, so the ideal situation is for the DC to be low enough that Assurance makes a Critical Success a guarantee, but that seems unlikely.

The Inventor’s class entry doesn’t require a Craft check to do anything built into the class (such as rebuilding your destroyed construct) except to trigger the Overdrive Action, which uses the “Standard” DC for your level, and that seems to be the best answer available. Tragically, Assurance won’t be a magic bullet here. It oscillates in and out of being a guaranteed Success depending on your level. Of course, that means that with maximized ranks, maximized Intelligence, and maybe an item bonus, you can roll a Critical Success reasonably often.

Your Construct Companion is limited in how it can benefit from items. “The only item bonuses they can benefit from are to Speed.” This means no item bonuses to attack, AC, damage, saves, skills, etc. Improvements to your companion’s stats come almost exclusively from advanced along the Advanced, Incredible, Paragon track.

Modifications

  • Accelerated MobilityGG: Extra movement speed is a helpful way to avoid spending your minions’ actions to Stride multiple times in one turn.
  • Amphibious ConstructionGG: Only useful if you expect to be adventuring in and around water.
  • Increased SizeGG: This causes your construct to occupy more space, which can be helpful for protecting squishy members of your party, but may also make it difficult to bring your construct into small spaces. Construct companions can be ridden so long as they’re one size larger than the rider, but if you just want to ride your construct it’s easier to play a small Ancestry. Your construct doesn’t get improved reach. Give a lot of thought to this before picking it.
  • Manual DexterityGG: Helpful if you need your companion to do stuff like open doors or chests.
  • Projectile LauncherGG: d4 damage isn’t fantastic, but it improves the same way that your construct’s melee attack improve without costing anything extra.
  • Sensory ArrayGG: Tremorsense is a great way to detect and locate insibile enemies.
  • Wonder GearsGG: This is a weird trio of skills. Stealth is probably the most impactful of the three, and while proficiency in Stealth is nice so that your construct isn’t the only one in the party who isn’t snreaky, they’re certainly not going to replace a real Scout.

Breakthrough Construct Modifications

  • Advanced WeaponryGG: Entangling Form and Heft Composition are both good choices for a melee attack and Modular Head is good for ranged attacks.
  • Antimagic ConstructionGG: A good bonus that will apply frequently.
  • Climbing LimbsGG: A climb speed is the next best thing to flight. This typically won’t help you in combat unless your construct also has ranged weapons, but outside of combat it’s very useful.
  • Durable ConstructionGG: Not enough hit points considering the cost.
  • Marvelous GearsGG: Stealth remains the only one of the three skills which is likely to see consistent use by your construct.
  • Turret ConfigurationGG: The improved range increment is nice, but the damage impovement isn’t enough.

Revolutionary Construct Modifications

  • Flight ChassisGG: Flight is really good. Just remember that if a creature doesn’t spend an Action to fly it will fall, so you may need to keep commanding your minion or have it land. A minion will “use no actions except to defend themselves or to escape obvious harm”, but I’m not sure exactly how to apply that here. Talk to your GM. I would rule that the minion either hovers or flies to the nearest safe landing place.
  • Miracle GearsGG: Skip straight to Legendary on two skills. Weirdly, this doesn’t automatically improve the skills provided by Wonder Gears or Marvelous Gears. Your companions Intelligence modifier is still -2 and their Charisma modifier is +0. Don’t get any ideas about it having intellectual debates or being your party’s Face.
  • Resistant CoatingGG: Constantly useful. 5 doesn’t feel like a ton of damage, but it will add up very quickly.
  • Runic KeystoneGG: This allows a lot of interesting possibilities, but consider the cost of your Revolutionary Modification plust the cost a worthwhile rune compared to other modification options like Resistant Coating.
  • Wall ConfigurationGG: By this level your party’s casters likely have many area damage options like Wall of Fire which can deal ongoing damage in an area, and this works like any solid wall to hold enemies within that area. Unfortunately, enemies can still attack your construct, and since it’s a creature they Shove and Trip it. You may need to stand behind your companion and Aid it to help it stay upright. Even then, this tactic is only useful if your allies have a suitable effect to bring down your enemies, your enemies will be contained by the wall, and your enemies can’t simply destroy your companion to get to you.

Weapon Innovation

If you’ve ever looked at Pathfinder 2e’s literal hundreds of weapon options and thought “I can’t find one that does exactly what I want”, you’re crazy and also you should consider the Weapon Innovation.

Despite being published in Guns and Gears and having guns just several pages away, the Inventor’s modification options for ranged weapons are surprisingly few in number. There are still a few options if you have dreams of playing a mad spoon gun inventor or you’re on a mad quest to turn a harmona gun into a grappling hook launcher, but the build versatility isn’t nearly so broad as melee weapons.

Like you might expect, the Weapon Innovation is the most effectively offensively. But other innovations mostly get the same access to damage boosts (Overdrive, Weapon Specialization, Offensive Boost, etc.), so the increase offensive effectiveness comes more from versatility of tactical options than from raw effectiveness with your Strikes.

Modifications

  • Blunt Shot (Ranged Only)GG: The ability to nonlethally shoot someone is only occasionally useful, and while Versatile is nice, Modual Hear is a better solution to the same problem.
  • Complex Simplicity (Simple Weapon Only)GG: This brings a simple weapon in line with martial weapons. For example, a light mace with Complex Simplicity is very similar to a short sword. A mace with Complex Simplicity is very similar to a warhammer. That explanation should prompt you to ask “but then why don’t I just use a martial weapon?”, and the answer in most cases is “you probably should”. But there are some edge cases where isn’t a martial equivalent like the Knuckle Duster and more unique weapons like the Clan Dagger which may be appealing.
  • Dynamic WeightingGG (One-handed Melee Weapon Only; Can’t Have the Agile, Attached, or Free-hand Trait): Generally it’s easier to just use a two-handed weapon, but there may be edge cases where there isn’t an equivalent two-handed weapon.
  • Entangling Form (Melee Only)GG: A great way to make grappling effective, and you may be able to use this to grapple at range if you have a reach weapon like a whip or a polearm.
  • Hampering Spikes (Melee Only)GG: Hampering is not a good trait.
  • Hefty Composition (Melee Only)GG: Shove is a decent trait if you invest heavily in Athletics to make the Shove action work. Put this on a longsword and you can deal all three wepon damage types.
  • Modular HeadGG: Only situaitonally useful, but you’ll never need to worry about resistance to specific weapon damage types.
  • Pacification Tools (Melee Only)GG: The Nonlethal trait is rarely useful, and Disarm is only useful against the subset of enemies that use weapons.
  • Razor Prongs (Melee Only)GG: Trip is excellent, and Versatile is good, too. Throw this on a weapon like a warhammer and invest in Athletics.
  • Segmented FrameGG: Too situational.

Breakthrough Weapon Modifications

  • Advanced Rangefinder (Ranged Only)GG: The extra range is nice, but Backstabber only adds 1 damage per hit.
  • Aerodynamic Construction (Melee Only)GG: Sweep is fine, but it’s only situationally useful since you can’t guarantee that enemies will be positioned to make Sweep useful.
  • Inconspicuous Appearance (Melee Only):GG: Backstabber only adds 1 damage and the need to conceal your weapons is rare.
  • Integrated Gauntlet (One-Handed Weapon Only; Can’t Have the Two-Hand Trait)GG: If you like to use items (and you probably do), this can be very useful. Put a shield in your other hand and leave your weapon hand free for items and such.
  • Manifold AlloyGG: Only situationally useful, but if you’re planning to face enemies like fey and lycanthropes, this is very useful.
  • Rope Shot (Ranged Only)GG: Ranged trip is a great way to keep enemies at a distance and also to knock flying enemies to the ground.
  • Tangle Line (Thrown Only)GG: Ranged trip is a great way to keep enemies at a distance and also to knock flying enemies to the ground, but if you want a throwing weapon with Ranged Trip, the Bola already exists.

Revolutionary Weapon Modifications

  • Attack RefinerGG: Combining Agile and Backswing or Backswing and Forceful (or all three, but few weapons support that) can be a very effective choice if you frequently make multiple Strikes in one turn.
  • Deadly StrikeGG: Deadly is great if you’re scoring critical hits frequently. Personally I wouldn’t use this with a weapon that’s already Deadly because upgrading the Deadly die to d12 isn’t as impactful as adding a d8 to a weapon that doesn’t have it. If the weapon had Deadly d4 they wold be equivalent, but there are no Deadly d4 weapons as of this writing.
  • Enhanced DamageGG: Simple but effective. Works especially well with Megaton Strike.
  • Extensible WeaponGG (Melee only): Imagine a whip with 15-foot reach. It’s nice.
  • Impossible AlloyGG: Technically this is only situationally useful, but with 7 different types of metal there may be enough enemies where this matters that it’s worth the cost.
  • Momentum RetainerGG (Melee only): Similar to Attack Refiner. Combining any two or three of Agile, Backswing, and Forceful makes for a very powerful weapon, but it’s hard to accomplish.
  • Omnirange StabilizersGG (Ranged only): Very few weapons have the Volley trait, and for other weapons it’s rare to be in a situation where you need that much range. Thrown weapons are a possible exception since they typically have very short range.
  • Rune CapacityGG: Weapon runes can do a lot. Even runes which are inexpensive by this level might be more impactful than