Mad Geniuses

Necessity is the mother of invention, or so some claim, but sometimes the invention precedes its necessity. Those who craft and reshape the world around them through mechanical means are known as tinkerers. A tinkerer is much more than an artisan; their creations can often subvert and circumvent the barriers of physical laws. They tap into the ambient magical energy that suffuses the planes to fuel their machinations.

Shared among all tinkerers is the ability to craft at impossible speeds and the synchronotic discovery of the Affect Engine, a machine that consumes ambient magical energy and spits out elemental work. Rumored to have been first invented by a master poet tinkerer, the “affect” from its name is said to come from "the passion, tension, and frustration that is enticed by the fire, lightning, and cold it produces."" It is mysterious in construction and function to all but other tinkerers.

The tinkerers' greatest strength is their magnanimous flexibility. Each one can craft at increasingly faster rates and is capable of constructing almost any non-magical object with a coin value. Their role in combat is dictated more by their subclasses than their base class and, depending on their source of inspiration, can fit right alongside anyone on the front, side, or backlines, though seldom overshadowing them. Primarily weapon-based casters, tinkerers will use their magic to empower their weapon attacks or fuel their Power Appliances. Their wide spell selection reflects the kind of wild machinations a mad scientist might be up to. Tinkerers tend towards singular obsessions, careening them towards maddening heights in the pursuit of knowledge and creation.

Quick Build

You can make a tinkerer quickly by following these suggestions. First, make Intelligence your highest ability score, followed by either Strength or Dexterity. Second, choose the guild artisan background. Third, choose a crowbar to use as a power tool (see Power Appliances list.)

Class Features

As a tinkerer, you gain the following class features.

Object Armor Class Table

For Hit Points, consider the suggested values from the DMG’s Object Hit Point table (pg. 247) reproduced below:

Object Hit Points Table

Power Appliance

Affect engines can be incorporated into your constructions. They can supply power or perform some other task. Many examples of Power Appliances, as well as a general guide on their design, are detailed at the end of this document. Work with your DM to expand this list. In general, if a construction with an attached affect engines is destroyed, all attached engines are destroyed with it.

Sparknotes

At 2nd level, you scribe a sparknote containing six 1st-level spells of your choice. Your sparknotes contain the results of your research into the tinkerer spells you know.

Preparing and Casting Spells

The tinkerer table shows how many spell slots you have to cast your spells of 1st level and higher. To cast one of these spells, you must expend a slot of the spell’s level or higher. You regain all expended spell slots when you finish a long rest.

You prepare the list of spells that are available for you to cast. To do so, choose a number of spells from your sparknotes equal to your intelligence modifier + half your tinkerer level rounded down (minimum of one spell). The spells must be of a level for which you have spell slots.

You can change your list of prepared spells when you finish a long rest. Preparing a new list of spells requires time spent studying your sparknotes and calculating the formulas and equations you must make to cast the spell: at least 1 minute per tinkerer level for each spell on your list.

Spellcasting Ability

Intelligence is your spellcasting ability for your spells, since you innovate through study and inspiration. You use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a spell you cast and when making an attack roll with one.

Ritual Casting

You can cast a tinkerer spell as a ritual if that spell has the ritual tag and you have the spell in your sparknotes. You don’t need to have the spell prepared.

Spellcasting Focus

You can craft a scientific instrument through your construction class feature by cobbling together any materials that look sufficient enough to resemble a refracting prism (crystal), puzzle cube (orb), ruler (rod), meter stick (staff), or pointer (wand). You can use a scientific instrument as a spellcasting focus for your tinkerer spells.

Learning spells of 1st Level and Higher

Each time you gain a tinkerer level, you can add one spell of your choice to your sparknotes. Each of these spells must be of a level for which you have spell slots, as shown on the tinkerer table. On your adventures, you might find other spells that you can add to your sparknotes.

Affect Discharge

When you hit a creature with a weapon attack with an attached affect engine, you can expend one spell slot to deal additional damage to the target. The additional damage is 2d6 for a 1st-level spell slot, plus 1d6 for each spell level higher than 1st, to a maximum of 5d6. The damage type is according to the engine type.

If a creature you can see hits with a weapon attack using a weapon that has one of your affect engines attached to it, then you may as a reaction expend a spell slot to deal additional damage like above.

Expertise

At 2nd level, choose two of your tool proficiencies or one of your skills and one of your tool proficiencies. Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies. At 10th level, you can choose two more of your proficiencies in this same manner to gain this benefit.

Field of Study

When you reach 3rd level, you determine your field of study, an affinity for a particular branch of science. Look to the Bombardier, the Mechanic, or the Steam Knight, all detailed at the end of the class description.

Your choice grants you features at 3rd level and again at 7th, 10th, 15th, and 20th level. Those features include genius sparks.

Instacraft

From 5th level you can use your Construction feature to craft an item with a value of 1 gp or less as an action. You can do this a number of times per day equal to your intelligence modifier.

At 11th level, the value increases to 25 gp. At 18th, 100 gp.

Switch Function

At 6th level, a breakthrough increases the flexibility of your engines. As an action or bonus action, you can change the elemental type of an affect engine you are touching to another type. To use this feature on an engine, the engine must not be performing any task. An engine that is attached to an object, but is otherwise not doing anything, is not considered to be performing a task.

Tireless

Also at 6th level, you can craft for the entirety of long rests while still gaining their benefits. However, you can only craft during long rests for a number of consecutive days equal to your Constitution modifier, minimum 1. For each day beyond that spent crafting during long rests, you end the long rest with a level of exhaustion.

Improved Affect Discharge

At 8th level, you upgrade your affect engines to consistently output bursts of energy. Once per turn whenever you hit with a weapon attack with one or more attached engines, you can cause the attack to deal an extra 1d8 damage of a type according to the engine.

This extra damage increases to 2d8 at 14th level. Additional engines do not increase the damage, but you may choose between damage types when you make an attack.

Intense Concentration

By 14th level, you have developed the ability to repulse attempts to befuddle your mind through brute intellectual force. You add your Intelligence modifier to your Wisdom and Charisma saving throws.

Bombardier

Bombardiers study the development of anti-personnel munitions. Crafting unique ammunition and augments to their engines, these incorrigible engineers forge new ways to wreak melty death upon their foes.

Mechanic

Specializing in mechanical engineering, mechanics push the limits of their Power Appliances. Experimentation on improving the efficiency of the affect engine yields an unintentional but exploitable explosive self destruction. Exceeding the bounds of discovery through ingenuity, these incorrigible engineers wrought creation and destruction in their wakes.

Megarobo

Huge construct, unaligned

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• Armor Class Your Spell save DC (mechanical armor)
• Hit Points 200(16d12 + 96)
• Speed 50 ft.

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STR	DEX	CON	INT	WIS	CHA
20 (+5)	20 (+5)	22 (+6)	4 (-4)	14 (+2)	1 (-5)

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• Damage Resistances poison, psychic; bludgeoning, piercing, and slashing from nonmagical weapons
• Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
• Senses infrared vision 120 ft. (see heat sources clearly) passive Perception 12
• Languages ---

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Designed. All effects targeting the megarobo that trigger physical saving throws uses your spell attack bonus for the saving throw instead.
Magic Weapons. The megarobo’s weapon attacks are magical.
Piloted. All effects targeting the megarobo that trigger mental saving throws target the pilot instead, using the pilot’s mental saving throws in place of the megarobo’s.
Siege Monster. Megarobo attacks deal double damage to objects and structures.

Actions

Unarmed Strike. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 3d4 + 5 bludgeoning damage + 2d8 Improved Affect Discharge damage.

Customize your Megarobo

The types of engines you choose when you activate this feature grants additional benefits. You choose which benefits you want at the moment of transformation. Unless otherwise stated, you cannot choose a feature more than once. Some benefits can be improved by dedicating additional engines to it. These additional engines cannot be counted for other benefits.

Features may have cooldown periods, which mean that a certain number of rounds must pass before you can use the feature again. You reduce cooldowns by 1 at the start of each of your turns. When a cooldown reaches 0, you regain a use of that feature, and the cooldown resets to its original number. “Z Weapons” can be summoned from and stowed in the megarobo using an object interaction.

• Coolant. Requirement: 1 cold engine. As a bonus action, you can make the cooldown of one of your megarobo features drop by 2 instead of 1 at the start of your next turn.
• Cryogenic Core. Requirement: 4 cold engines. Increase the duration of the megarobo from 1 minute to 2 minutes.
• Motor Control. Requirement: 1 lightning engine. Your megarobo applies your proficiency bonus to two Strength and Dexterity skill checks of your choice.
• Synaptic Gyros. Requirement: 2 lightning engines. The megarobo can take the dash or disengage action as a bonus action on each of its turns.
• Flamethrower. Requirement: 1 flame engine. As an action, recreate the effects of the spell burning hands as if it were cast with a 3rd level spell slot. Each additional flame engine increases the damage by 1d6. Cooldown: 3.
• Flight boosters. Requirement: 2 flame engines. Gain a fly speed of 40 ft. Each additional flame engine increases the fly speed by 20 ft.
• Fog Machine. Requirement: 1 flame engine + 1 cold engine. As an action, recreate the effects of the spell Fog Cloud centered on yourself as if it were cast with a 3rd level spell slot. Does not require concentration. Cooldown: 3.
• Rocket Fist. Requirements: 1 flame engine + 1 lightning engine. Whenever you make an unarmed strike, object interaction, or grapple attempt, you may increase its range to 120 feet. You may target creatures and objects behind cover so long as you can trace a contiguous, unimpeded line between the megarobo and the target. You must use a bonus action to reel in your extended limbs. Cooldown: 2.
• Z-Bow. Requirements: Any 1 engine + 1 lightning engine + 1 cold engine. Two-handed, heavy. +9 to hit, range: 300/1200 ft., one target. Hit: 19 (3d8 + 5) piercing damage + 2d8 Improved Affect Discharge damage. The megarobo creates its own ammunition. You can make Affect Discharges with Z-Bow attacks, dealing a type of damage according to the chosen engine type.
• Z-Shield. Requirements: Any 1 engine + 1 cold engine. One-handed. +2 AC and resistance to the damage of the chosen engine type.
• Z-Sword. Requirements: Any 1 engine + 1 cold engine. Versatile. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 3d8 + 5/3d10 + 5 slashing damage + 2d8 Improved Affect Discharge damage. You can make Affect Discharges with Z-Sword attacks, dealing a type of damage according to the chosen engine type.

Genius Sparks

Bonus Proficiencies

When you choose this field of study at 3rd level, you gain proficiency with heavy armor, shields, and martial weapons.

Affect Armor

Starting at 3rd level, if an affect engine is attached to armor you are wearing and proficient in, then whenever a creature within 5 feet of you hits you with an attack, that creature takes 1d4 + your intelligence modifier affect engine type damage. If you have multiple affect engines attached to your armor, you choose which damage type to deal.

Additionally, while an engine is attached in this way, you can use any ability through a melee weapon you are wielding that normally requires an engine to be attached to that weapon.

At 15th level, the damage increases by 1d4.

Armor Engine Upgrade

Starting at 7th level, depending on the type of affect engine attached to your armor, you can as a bonus action activate a corresponding feature that lasts for up to 1 minute. You can only use one of these options at a time. Once you use this feature, you can’t use it again until you finish a short or long rest.

• Flame. You gain a 20-foot fly speed.
• Lightning. As an action you can magnetize objects you are holding in your hand or attract and repel magnetized objects and metals up to a distance of 60 feet. The object must not weigh more than 30 lbs. If an object you are attempting to attract or repel is being held by a creature, the creature must make a strength saving throw against your spell save DC, losing grip of the object on a failed save. If the object is being worn by a creature, they automatically succeed the saving throw. You can make improvised ranged attacks with objects you are attracting or repelling. You are proficient in these attacks, the damage die is 1d6, and you use your intelligence modifier for the attack and damage rolls.

Rocket Carriage

Requirements: 1 carriage + 2 flame engines.
Size: huge.
As an action, you may expend a 2nd level spell slot to propel the rocket carriage as if it were being pulled by a dashing draft horse (base speed 40 ft) for 1 minute or until you end it as a bonus action. Maintaining control of the carriage requires an Intelligence (Land Vehicle) check against a DC 10 at the start of each of the driver’s turns, losing control on a failed check. Each attached cold engine increases the duration by 1 minute. Each attached lightning engine reduces the DC by 5.

At Higher Levels. When you expend a spell slot of 4th level or higher, increase its base speed by 10 feet and the DC by 5.

Single Skyrider

Requirement: 10000 gp worth of good quality metal, 3000 gp worth of wood, 6000 gp worth of precious stones, and 1000 gp worth of glass (20,000 gp total) + 2 flame engines + 1 cold engine + 1 lightning engine.
Size: gargantuan.
Weight: 1000 lbs
A metal bird that roars through the sky, its rigid wings mocking the land. Can carry one pilot and one passenger, or 500 lbs. While riding in its cockpit, you may expend a 5th level slot to give it a fly speed of 600 feet for the next 10 minutes.
Wide Berth: the single skyrider cannot make tight turns. To turn 5 degrees to the left or the right, the single skyrider must move 30 feet forward. For example, to turn 45 degrees in one direction, the single skyrider needs to move 270 feet forward. Maintaining control of the skyrider requires an Intelligence (sky vehicle) check against a DC 15 at the start of each of the driver’s turns, losing control on a failed check. Each additional flame engines increase the fly speed by 200.

Each additional cold engines increase the duration by 10 minutes. Each additional lightning engines reduces the DC by 5.

Spell List

Tinkerer changelog

Credits

Tinkerer class authored and formatted by /u/Leuku
Document made using GMBinder
Special thanks to the folks at the Discord of Many Things, QalarValar's guide to homebrewery formatting, GirlGenius for the inspiration,

Previous Work