The Gearjack

Roguish Archetype: The Gearjack
“Anyone can pick a lock. I make the whole gate forget it ever had a hinge.”

In cities where steam hisses through grates and arcanical defenses hum behind brass plating, there exists a rare breed of rogue - not just a thief, not quite an inventor. These are the Gearjacks: saboteurs who make war on the machinery of power with nothing but a blade, a spark, and a mind trained to see failure points where others see fortification.

Becoming a Gearjack is rarely a choice. It’s a survival instinct. You might be a street-born runaway from the underrails of a capitol, learning to disarm turret-traps to sleep one more night. You might have fled a failed rebellion in a border city, having studied how to turn your former master’s arcanical guardians against him. Or perhaps you were a promising artificer - until you saw what your creations were really built for, and decided you’d rather break them than build more.

Some Gearjacks emerge from the underworld, trained by smuggler crews to disarm magical locks mid-escape. Others are military dropouts - field riggers who grew too clever, too curious, or too disloyal for command. A few are even scholars turned iconoclasts, having learned the deep truths of soulbinding or mechanical enchantment... and resolved to dismantle it all.

One way or another, you decided the world had far too many wards and locks in place.

Arcanical Cunning

At 3rd level, you gain:

Proficiency with Tinker’s Tools and Firearms, if you don’t have them already.

The Mending cantrip. It doesn’t count against your known cantrips.

If a target or creature is a Construct, you know it.

When using Thieves’ Tools or Tinker’s Tools to disable a trap, bypass a device, or dismantle a construct, you double your proficiency bonus.

You may attempt to discern the function of any non-unique mechanical or arcanic device after 1 minute of inspection, no magic required.

 

Level 3: Gearjack Rig

Level 3 Gearjack Feature 

You’ve crafted a modular contraption that houses several mechanical tools known as Rig Functions. Each Rig Function can be activated as a bonus action unless stated otherwise. You may use a Rig Function a number of times equal to your proficiency bonus per long rest.

You begin with two Rig Functions at level 3. You can change them after a long rest. You gain an additional Rig Function at levels 5, 9, and 13. Your options include:

1. Noise Emission Discombobulator (N.E.D.)
A clever muffler system you can slot onto your firearm. When you make an attack with a firearm while hidden, missing the target does not reveal your position.
Lasts for 1 minute.

2. Springlash Grapple
You deploy a high-tension grappling hook mounted to your wrist, belt, or elsewhere on your person. Choose one:
Travel: Move up to 50 feet in a straight line toward a solid anchor point you can see. This counts as movement and does not provoke opportunity attacks.
Pull Object or Creature: Make a Strength (Athletics) check vs. a DC based on the target’s weight:
DC 10 for equal weight
DC 15 for x2
DC 20 for x3+
On a success, the item or creature is pulled 25 feet toward you.

3. Arcanic Lock Tap
A quick-splice arcane bypass node that defeats basic security enchantments.
You can instantly unlock any non-magical lock you can touch, with no roll required.
You can also attempt to unlock a magically sealed lock by making an Intelligence check with Tinker’s Tools against a DC = 10 + spell level of the lock effect.

4. Magical Disappropriation Emitter (M.D.E.)
You deploy a small alchemically treated puck to a space within 10 feet. As it hums and sparks, it releases a wave of arcane disruption.
As an action, you toss the M.D.E. puck. It emits a 10-foot-radius burst equivalent to a 3rd-level Dispel Magic centered on itself.
All magical effects within range (including buffs, debuffs, illusions, or wards) are targeted by the dispel.
Treat your rogue level as your caster level for determining the effect.
The puck lasts 1 round before disintegrating.

5. Concealed Detonator Bolt
From a hidden launcher on your person, you launch a compact bolt that is charged with volatile elemental powder.
Make a Dexterity-based ranged weapon attack as a bonus action. On a hit, the Concealed Detonator Bolt deals 3d6 Force damage, and can trigger Sneak Attack.
Using this Gearjack Feature does not reveal you from stealth if the attack fails.

Arcanic Lock Tap

Arcanic Lock Tap

A quick-splice arcane bypass node that defeats basic security enchantments.
You can instantly unlock any non-magical lock you can touch, with no roll required.
You can also attempt to unlock a magically sealed lock by making an Intelligence check with Tinker’s Tools against a DC = 10 + spell level of the lock effect.

Concealed Detonator Bolt

Concealed Detonator Bolt
From a hidden launcher on your person, you launch a compact bolt that is charged with volatile elemental powder.
Make a Dexterity-based ranged weapon attack as a bonus action, with a range of 30 feet. On a hit, the Concealed Detonator Bolt deals 3d6 Force damage, and can trigger Sneak Attack.
Using this Gearjack Feature does not reveal you from stealth if the attack fails.

Magical Disappropriation Emitter (M.D.E.)

Magical Disappropriation Emitter (M.D.E.)
You deploy a small alchemically treated puck to a space within 10 feet. As it hums and sparks, it releases a wave of arcane disruption.
As an action, you toss the M.D.E. puck. It emits a 10-foot-radius burst equivalent to a 3rd-level Dispel Magic centered on itself.
All magical effects within range (including buffs, debuffs, illusions, or wards) are targeted by the dispel.
Treat your rogue level as your caster level for determining the effect, and your Intelligence score is the statistic used in magical contests.
The puck lasts 1 round before disintegrating.

Noise Emission Discombobulator (N.E.D.)

Noise Emission Discombobulator (N.E.D.)

A clever muffler system you can slot onto your firearm. When you make an attack with a firearm while hidden, missing the target does not reveal your position.

Lasts for 1 minute.

 

Springlash Grapple

Springlash Grapple

You deploy a high-tension grappling line from a launcher mounted on your person - and can use its powerful winch to either move 50 feet in a straight line towards a solid anchor point you can see, or to pull an item or creature 25 feet towards you. When using the grapple to move, the movement does not provoke attacks of opportunity. When using the grapple to pull an item or creature, you must make an athletics check based on that target's weight, compared to yours.
Athletics Check, DC 10 for an equal weight target
DC 15 for a target that weighs twice as much as you
DC 20 for x3 or more
On a success, the item or creature is pulled 25 feet toward you.

The Craftsman’s Eye

Level 9 Gearjack Feature

Arcanic Saboteur

Your precision strikes now interfere with the weave of magic and craftsmanship in enchanted defenses and forged bodies. When you deal Sneak Attack damage to a creature that meets any of the following criteria:

• It is a construct,
• It is wearing magical armor,
• It is benefiting from a magical protection spell (such as Mage Armor, Barkskin, Shield of Faith, Armor of Agathys, etc.),

You may apply one of the following Saboteur Effects in addition to the damage.

Thaumic Fracture

The target becomes vulnerable to the next damage type it takes before the end of your next turn.

Magnetic Bind

The target’s movement speed is reduced by half and it cannot take reactions until the start of its next turn.

False Recall

The creature must succeed on a Charisma saving throw, DC = 8 + your Int mod + your proficiency bonus, or be charmed by you until the end of your next turn. While charmed this way, they won’t target you with attacks or spells.

You can apply one Saboteur Effect once per turn, when you deal Sneak Attack to an eligible target.

These effects do not replace Sneak Attack damage, they add to it.

No saving throw is required unless otherwise stated.

Hack the Heart

Level 13 Gearjack Feature

Hack the Heart

You’ve studied the animating cores, control sigils, and enchanted matrices of arcanically forged beings. With a flick of your rig, a whispered command, or a well-placed blade, you can seize control of these systems - if only briefly.

Once per short or long rest, you may target one creature or device within 30 feet that meets one of the following criteria:

• It is a construct,
• It is a creature wearing magical armor,
• It is affected by a magical protection spell (Mage Armor, Stoneskin, Shield of Faith, etc.)
• It is a stationary arcanical device (e.g. turrets, gates, lifts, arcane locks, scrying nodes).

As an action, you make an Intelligence (Tinker’s Tools) check against a DC = 10 + the creature’s or device’s Constitution modifier + its proficiency bonus (if applicable). On a failure, the attempt fizzles. On a success, choose one of the following effects, which you may declare after learning if the target succeeded or failed:

Command Override (Creatures)
The target is overwhelmed by false inputs. Until the end of its next turn, it treats you as an ally, and will not attack or target you with abilities.
If it's a construct, you may issue a one-sentence command (e.g., “Flee,” “Protect me,” “Disable that door,”) that it will attempt to follow until it succeeds a Constitution saving throw, DC = 8 + your Int mod + your proficiency bonus, which it will attempt at the end of each turn.

Core Destabilization (Creatures or Devices)
You cause a rupture or feedback loop in the magical enchantments and matrices. The target takes 4d10 force or thunder damage (your choice), and must succeed on a Constitution saving throw, DC = 8 + your Int mod + your proficiency bonus, or be stunned until the start of your next turn.

Lockout Spike (Devices only)
You lock a device into a single function or state for 1 hour - no save is required. The state cannot require complex actions, and should be harmless or ineffectual.
A turret fires only blanks.
A gate stays open or closed.
An elevator rises but won’t descend.
A security rune loops the same 6 seconds endlessly.
The device will repeat or follow one command, to the best of its ability, that does not harm itself. Consult with your DM if your command is applicable to the Device.

The Cataclysm Rig

17th Level Gearjack Feature

Cataclysm Rig

You have perfected your personal rig, integrating volatile tools too unstable for public schematics. Once per long rest, you can unleash a Cataclysm Function - a devastating, unpredictable technique that overwhelms magical constructs, fortified positions, or entire battlefields.
You may activate one Cataclysm Function as an action. You must choose from the following options:

Arcane Cascade
You throw a compressed core of unstable enchantment into the battlefield. Choose a point within 60 feet. Every construct or creature wearing magical armor, or benefitting from a magical protection spell, within 20 feet of that point must make a Constitution saving throw (DC = 8 + your Int mod + your proficiency bonus).
On a failure, they take 10d6 force damage and are stunned until the end of your next turn.
On a success, they take half damage and are not stunned.

Ghoststep Bloom
You release a blast of radiant steam and arcanical static. You immediately become invisible until the end of your next turn and teleport up to 60 feet to a space you can see.
Every creature within 10 feet of where you vanished is blinded until the start of your next turn.
You leave behind a heavily obscured 10-foot-radius fog cloud that lingers for 1 minute or until dispersed.

Null Pulse Detonation
You slam a spike into the ground or an arcanical surface, unleashing a wave of dispelling interference.
Cast Dispel Magic at 6th level in a 30-foot-radius centered on yourself.
All active magical effects of 5th level or lower are automatically ended.
Magical traps are suppressed for 1 minute.
Constructs within range must succeed on a Wisdom saving throw (DC = 8 + your Int mod + your proficiency bonus) or become incapacitated for 1 round as their control cores scramble.