The following homebrew adds a modern option to the Rogue class in 5E TTRPGs. All of the core Rogue class abilities can stay rules as written; see the official 5E System Reference Document (SRD v5) for details. Note: This subclass has not yet gone through playtesting.
Gadgeteer
Some rogues rely on blades or bullets; you prefer blueprints and batteries. Gadgeteers are improvisational inventors who hack, tinker, and modify everything they touch. Whether you’re a corporate saboteur, a field engineer for hire, or a rogue scientist kicked out of your own lab, your tools are extensions of your imagination… and your unpredictability. (Think more MacGyver than Tony Stark.)
Level 3: Experimental Engineering
You build and wield prototype tech that no one else dares to handle.
Tinker’s Arsenal. You gain proficiency with Engineering Tools and Hacking Kits if you don’t already have them.
Whenever you take a Short Rest, you can assemble up to two temporary gadgets chosen from the list below. A gadget lasts until you finish your next Long Rest or it breaks after use.
Sample Gadgets (each use is an Action unless stated otherwise):
Shock Glove: Melee attack deals lightning damage equal to 1d6 + Dexterity modifier.
Flashbang Capsule: 10-foot radius; creatures must succeed on a Constitution saving throw (DC 8 + your proficiency bonus + your Intelligence modifier) or be Blinded until the end of your next turn.
EMP Spike: Disable one unattended electronic device or temporarily short out a robot for 1 round.
Microdrone: A tiny flying drone that can scout up to 100 feet away and transmits sound and visuals to your wrist display.
Adhesive Web Projector: Create a 10-foot sticky zone of difficult terrain.
You can swap out gadgets after any Short or Long Rest.
Level 3: Quick Assembly
You’ve learned to build or modify equipment in seconds. As a Bonus Action, you can do one of the following:
Rig Device. Make a Dexterity (Engineering Tools) check to repair, disable, or modify a device.
Deploy Gadget. Activate or throw one of your temporary gadgets.
Improvised Use. Use a simple object (like a canister, wire, or battery) as a makeshift tool or distraction, granting advantage on your next Sleight of Hand or Deception check this turn.
Level 9: Adaptive Schematics
You can instantly recalibrate your tech to exploit weaknesses or counter threats.
Reactive Tinkering. When you deal Sneak Attack damage, you can infuse the attack with an element type (acid, fire, lightning, or sonic). The damage type changes to that element.
Modular Mastery. When you make a Dexterity or Intelligence check using technological devices, you can add your Sneak Attack dice to the roll instead of using them for damage once per short rest.
Level 13: Overclocked Systems
Your devices operate on the edge of meltdown, but that’s where the magic happens.
Overcharge. When you use a gadget or a device with charges or fuel, you can push it beyond normal limits. Roll 1d6:
* On a 1, the device fails spectacularly (GM decides how).
* On a 2-5, it functions normally.
* On a 6, it produces an enhanced effect: damage or duration is doubled, range increases by 50%, or another dramatic improvement occurs.
Backup Power. You can attune to up to four technological or prototype devices simultaneously.
Level 17: Master of Improvisation
You think faster than systems can break.
Instant Blueprint. As a Bonus Action, you can fabricate a temporary gadget from your inventory or scrap. Choose any effect from your Experimental Engineering list or invent a new one of similar scope (GM’s discretion). You can use this feature a number of times equal to your Intelligence modifier per long rest.
Chain Reaction. When you trigger a gadget that affects multiple targets, you can cause a secondary detonation, surge, or overload affecting an additional area within 20 feet.