Gadgeteer

This subclass was created by Kibblestasty. If you enjoy this content, consider showing your support by checking out his other content.

Note: A few changes were made to balance this from KT's original version. Your 3rd-level feature, "Pyrotechnic Gadgets," now requires resources to use, as before you could lob infinite aoe sneak attack grenades from within infinite fog clouds that you could see through.  As a result of the new resource limit, shaped charges has been buffed to deal siege damage to buildings if you spend at least one minute planting it.

Swinging from a grappling hook before dropping a smoke bomb, rigging a stubborn lock to blow, or rejiggering traps to spring on those that set them, the Gadgeteer lives by fast paced innovation and thinking outside the box on the fly... sometimes literally.

Specializing tools that let themselves in and out of trouble, they don't fight fair, relying on things that go "boom", "zap" or "whirr". They live on the edge of their own explosions, though often rewriting the story in later retellings that they doffed their darkened goggles as they walked away slowly, omitting the singed seat of their trousers and yelping.

Tinker's Knack

3rd- level Gadgeteer feature

You are proficient with tinker's tools and may add double your proficiency bonus to ability checks made using them.

Grappling Hook

3rd-level Gadgeteer feature

You've mastered both the creation and use of your most important gadget, the grappling hook. As a bonus action, you may target a surface, object or creature within 20 feet. If the target is Small or smaller, you can make a Strength (Athletics) grappling check to pull it to you and grapple it (automatically succeeding against objects that are not being worn or carried unless the DM sets a difficulty for a particularly complicated scenario).

Alternatively, if the target is Medium or larger, you can choose to be pulled to it. This automatically succeeds, but this does not grapple it, though if it is a surface or large object, you can choose to hold onto at the point you grappled if there is something to grab onto. Attacks of opportunity generated by this movement have disadvantage.

Gadget DC

Your gadgets are a combination of innovative mechanical parts and magic. You use your Intelligence for gadget based effects when they refer to a spell attack roll or spell save DC.

Gadget DC = 8 + your proficiency bonus + your Intelligence modifier
Gadget modifier = your proficiency bonus + your Intelligence modifier

Pyrotechnic Gadgets

3rd-level Gadgeteer feature

You gain access to an important arsenal of things that explode. Forgoing some subtlety for firepower, you gain the following options:

Smoke Bomb: As an action, you can use this to cast fog cloud centered on yourself without expending a spell slot. It lasts a number of rounds equal to your Intelligence modifier and does not require concentration. When cast in this way, you can set the radius at 5, 10, 15, or 20 feet. You may only have the effects of one fog cloud up at a time, and any previous fog cloud dissipate upon using this ability again.

Explosive Surprise: As an action you can toss explosives at a point within 30 feet. Creatures within 5 feet of the target point must make a Dexterity saving throw against your Gadget DC or take damage equal to your Sneak Attack damage. If you are hidden from a creature, it makes the Dexterity saving throw with disadvantage. This counts as dealing Sneak Attack damage.

Shaped Charge: As an action, you can place a charge on an object, building or surface within 5 feet. At the start of your next turn, the charge detonates, dealing damage equal to your sneak attack to the object, build or surface it was placed on, and half as much damage to any creature within 5 feet of it. If you spend at least 1 minute placing this on a structure then the explosion has the siege property (double damage to structures) and you may wait for up to one hour before detonating it remotely so long as you are within 100 feet when you do. 

Each of these abilities may be used for free once per short rest. You also have a pool of Crafted Gadgets equal to 1 + your Intelligence modifier + your Proficiency Bonus. You may expend a use of a crafted gadget to use any one of these abilities. You regain all uses of your crafted gadgets after taking a long rest.

Clever Inventions

9th-level Gadgeteer feature

You have thought up some additional brilliant inventions to assist with your adventuring duties.  You may select two of the following, and gain one additional choice when reaching 13th level:

Gliding Cloak

You make a cloak that allows you to glide when falling. When you fall more than 10 feet and aren't incapacitated, you can use your reaction to spread this cloak, reducing your falling speed to 30 feet a round and take no falling damage. While falling in this manner toward the ground under normal gravity, you can move horizontally 2 feet for every 1 foot you descend.

Mechanical Arm

You create a mechanical arm, giving you an extra hand. This mechanical arm only functions while it is mounted on gear you are wearing, but can be operated mentally without the need for your hands. This mechanical arm can serve any function a normal hand could, such as holding things, making attacks, interacting with the environment, etc, but does not give you any additional actions.

Mechanical Familiar

You can create the blueprint for a small mechanical creature. At the end of a long rest, you can choose to create a mechanical familiar based on it, and cast find familiar spell without expending a spell slot. The familiar's type is Construct. This construct stays active until you deactivate it or it is destroyed. In either case, you can choose to reactivate it at the end of a long rest.

Sight Lenses

You create a set of lenses you can integrate into a set of goggles, glasses, or other vision assistance that allow you to see through darkness and obscurement. You can see through fog, mist, smoke, clouds, and non-magical darkness as normal sight up to 15 feet.

Among the Blasts

9th-level Gadgeteer feature

When you successfully avoid damage from an area of effect with your Evasion feature (including from your own effects), you can use your reaction to move up to your movement speed until you are just outside the edge of the effect. This movement does not provoke attacks of opportunity.

Deadly Surprise

13th-level Gadgeteer feature

Your technical expertise expands. The radius of your Explosive Surprise and Shaped Charge becomes 10 feet.

Ultimate Improvisation

17th-level Gadgeteer feature

You can solve a wide array of problems with your Gadgets at a moment's notice. Over the course of 1 minute you can construct a gadget capable of casting any spell of 4th level or lower on the Wizard spell list. This gadget lasts until used, or you construct another gadget (dissembling it in the process).

You can do this a number of times equal to your Intelligence modifier before you must complete a long rest to create additional improvised gadgets with the feature.