Machinist

Artificer Subclass — Campaign homebrew for Heretics of the Old Gods

Overview

Anyone with training can drive a crawler. A Machinist is the crawler — they built it, maintain it, and know every weld, every jury-rigged component, every noise it makes and what that noise means. In a valley where the Deathwish Run is a career and the racing syndicates and haulage gangs run on rigs held together by the people who understand them, a Machinist is the one who can coax a dying engine through one more run and knows exactly where to source the part that shouldn’t exist.

This mastery is specific. A Machinist’s power lives in their rig — see Rig Rules for the full vehicle system this subclass builds on. Separated from it, a Machinist is a capable mechanic and little more; their expertise is bound up in the machine.

Machinist Spells

You always have the following spells prepared once you reach the levels shown. They don’t count against the number of spells you know.

Artificer Level	Spells
3rd	expeditious retreat, longstrider
5th	cloud of daggers, heat metal
9th	haste, blink
13th	freedom of movement, stoneskin
17th	animate objects, wall of force

Component Slots

Your rig’s component slots increase with your level in this class, as shown on the Machinist Rig table. This is the same progression given in Rig Rules, reproduced here for reference.

Artificer Level	Skirmisher	Hauler	Ruiner
3rd	3	4	5
5th	4	5	6
9th	5	6	7
15th	6	7	8

Features

3rd Level: Vehicle Expertise

You gain proficiency with land vehicles and with tinker’s tools (if you already have tinker’s tools, gain proficiency with smith’s tools instead). Additionally, you can make Resources checks — an Intelligence (Investigation) check to source rig components, as described in Rig Rules. Anyone can attempt to source parts, but without this feature the Resources DCs are 5 higher; you know the scrapyards, fences, and gang caches of the Hellcatch better than anyone.

3rd Level: The Rig

You have built a rig — a crawler-class vehicle, yours, that you maintain and keep running. Choose a frame (Skirmisher, Hauler, or Ruiner) and build it per Rig Rules.

If your rig is destroyed, you can build a new one over downtime with tools, materials, and a fresh frame — though the specific accumulated modifications that made the old one yours are gone.

5th Level: Practiced Hands

Your familiarity with your own machine lets you do something no ordinary crew can: while you are at the helm, you can operate one action station — firing a mounted weapon, working a grapple rig, and so on — using your bonus action, piloting and fighting at once where anyone else would need a separate crew member.

5th Level: Field Repair

As an action while aboard or adjacent to your rig, you can perform an emergency repair drawn from your own kit. Choose one:

• If your rig has wreck points, clear one wreck point. (Wreck points must be fully cleared before a rig can be restored from 0 HP — see Rig Rules.)
• Otherwise, restore 2d8 + your Intelligence modifier hit points to the rig.

You can use Field Repair a number of times equal to your Intelligence modifier (minimum once) per long rest.

9th Level: Overclock

As a bonus action while at the helm, you push your rig past its rated limits for 1 minute. Choose one benefit for the duration:

• +10 ft to the rig’s base speed per segment.
• Advantage on the rig’s control checks and mishap checks.
• The rig’s next ram this turn deals maximum damage.

You can Overclock a number of times equal to your Intelligence modifier (minimum once) per long rest. Each Overclock strains the machine: it takes wear damage equal to your frame’s wear die × the number of times you’ve Overclocked this long rest (Skirmisher 1d6 / Hauler 2d6 / Ruiner 3d6 per multiple). Your first Overclock of a long rest deals ×1, your second ×2, and so on.

15th Level: Indispensable

While you’re aboard, your rig is never quite finished:

• Field Repair becomes a bonus action.
• When you use Field Repair to restore hit points, roll it twice and use the higher total.
• Once per long rest, you can perform an emergency restart: as an action, clear all wreck points and immediately restore your rig to 1 HP, getting it running again. It must be properly repaired within 1 day or it immediately drops to 0 HP and regains any cleared wreck points.