All Monsters in "Engineer"

Name	Level
Artillerist	3
Demolitionist	4
Driver	2
Dynamo	8
Gadgeteer	6
Gunsmith	1
Juggernaut	13
Mechanic	1
Rocketeer	6
Toymaker	3

Engineer

Source NPC Core pg. 42
Although relatively uncommon across much of Golarion, the frequently eccentric but undeniably brilliant minds who create elaborate devices of clockwork, gunpowder, and steam often loom much larger in the public eye than their numbers would suggest.

Engineering Device Malfunctions

When making an attack or activating an ability granted by a mechanical device that has been poorly maintained or is of shoddy construction, an engineer must attempt a DC 5 flat check after making the relevant attack roll or skill check. On a failure, the action is lost and the device misfires spectacularly (roll on the Device Malfunctions table). A device misfire doesn't affect the amount of time that must pass before some abilities can be used again.

Device Malfunctions

d6	Effect
1	Fizzle The device jams or short-circuits. If the triggering action was an attack, it retroactively becomes a critical failure. The engineer must use an Interact action to reset the device before it can be used again.
2	Backfire The device violently explodes, disabling it and dealing 1d6 bludgeoning damage for every 2 levels the engineer has in a 5-foot burst centered on the device. The device is broken until the engineer Repairs it.
3	Off-Target If the triggering action was a targeted attack, the attack instead targets another creature (other than the engineer) within 10 feet of the intended target, determined randomly by the GM. If no such target exists, the attack misses.
4	System Reset A burst of feedback momentarily shuts down all the engineer's devices. The engineer can't use attacks or abilities granted by any personal engineering device, potentially including movement speeds, until the start of their next turn.
5	Overheat The overstressed device generates a wave of intense heat. The device burns the engineer for 4d6 fire damage and 2d4 persistent fire damage, with a basic Reflex save. The DC is equal to the engineer's Fortitude DC. The engineer can Release the item before rolling to improve their degree of success on the save by one step.
6	Delayed Reaction The device fails to function, having no apparent effect. At the start of the engineer's next turn, the device automatically activates. The GM chooses any target or area at random.

Brigh

On Golarion, science and magic coexist, and many engineers worship Brigh, the deity of clockwork, invention, and time. She's often invoked when an inventor needs inspiration or is on the clock and needs the next few hours to go slower. Often, engineers engrave small icons of Brigh's religious symbol—a mask in her likeness.

Crossover Ancestry NPCs

Several of the NPCs elsewhere in NPC Core can fit well in this group: Goblin scavenger (level 4), kobold trapper (level 2)

Firearms

Multiple engineers use firearms, technology that's present in relatively small numbers on Golarion. These are uncommon, simple, and martial weapons, so many player characters can use them. If you want to avoid putting the items in their hands, swap out the firearms with crossbow or similar weapons. More firearms and the gunslinger class appear in Pathfinder Guns & Gears.

Gadgets For PCs

Since engineers often carry unique gadgets, your player characters will likely want to salvage and reuse those items. If you want to do this in your games, you can either let them use the items primarily as written or convert them into consumable gadgets. In any case, these items are typically unstable when salvaged, usable once to a few times or subject to misfires.

Mechanical Allies

Often, engineers are accompanied by mechanical creatures of their own creation, like clockwork hounds or mechanical birds. To build encounters including such creatures, you can either adapt an existing construct (such as an animated object) or change an animal's trait to construct and give it immunity to bleed, death effects, disease, doomed, drained, fatigued, healing, nonlethal attacks, paralyzed, poison, sickened, spirit, unconscious, vitality, and void. You might want to reduce its HP slightly to compensate.

Misfires

Firearms that are improperly maintained or subjected to unusual strain can misfire. If a creature attempts to fire a firearm that was fired the previous day or earlier and hasn't been cleaned since, it rolls a DC 5 flat check before making its attack roll. If it fails this misfire check, the weapon misfires and jams. The attack is an automatic critical failure, and a creature must use an Interact action to clear the jam before the weapon can be reloaded and fired again. Once a creature has spent at least an hour cleaning a weapon, no one needs to roll for a misfire for that weapon until the next day unless an effect says otherwise.