Unstable Inventor

Every discipline has its heretics. Scholars who, in the course of ordinary inquiry, encounter phenomena the established theories cannot account for. Most file the anomaly away and move on. The Unstable Inventor is what happens when a scholar refuses.

So far, the discipline is one of exactly one practitioner. There are no papers, no peers, no convened symposia. There is a single researcher, a single Instrument, and a growing body of field notes written in an increasingly defensive tone.

Central to the work is scarlet radiation. A faintly glowing, faintly humming emission that manifests around certain artifacts, beneath certain skies, and, increasingly and disconcertingly, around the Inventor themselves. They measure it. They chart its decay curves. They build the Instrument to channel it, and then insist, with increasing strain, that what the Instrument does is not magic. The evidence continues to mount.

The Instrument itself is the Inventor's signature. A handheld device of their own making, part spellcasting focus and part diagnostic apparatus. Through it the Inventor runs Protocols, procedures with reassuringly technical names that in practice embolden allies, unsettle enemies, and suspend the immediate laws of physics in a tidy thirty foot radius. Every Protocol leaves its target faintly irradiated, a residue of scarlet light that lingers far longer than any Inventor can convincingly explain away.

The discipline, such as it is, prizes reproducibility and resents mystery. The life of its sole practitioner is the progressive collapse of both. Each successful experiment narrows the gap between what the Inventor has called an anomaly and what the world has always, unconcernedly, called magic. Whether they will come to peace with this, or double down, or simply keep running the numbers until the numbers run them, is an open question. Their published stance, for now, remains that results are "not inconsistent with magical phenomena." Which is not, they will emphasize, the same thing as saying so.

Scarlet Theorist Spells

You always have certain spells prepared after you reach particular Artificer levels, as shown in the Scarlet Theorist Spells table. These spells count as Artificer spells for you, but they don't count against the number of Artificer spells you can prepare.

Artificer Level	Spells
3rd	chromatic orb, command
5th	enlarge/reduce, mirror image
9th	counterspell, slow
13th	banishment, confusion
17th	hold monster, wall of force

Tool of the Theorist

When you choose this subclass at 3rd level, you gain proficiency with one artisan's tool of your choice. If you are already proficient with every artisan's tool, you instead gain proficiency in one skill or one language of your choice.

Unstable Invention

At 3rd level, you construct a unique handheld device, the Unstable Invention, also called the Instrument. Over the course of a long rest, using artisan's tools with which you are proficient, you craft it to a form of your choosing. Common expressions include a scarlet-threaded clockwork auroscope, a humming phial on a chain, or a pocket loom that weaves light.

The Unstable Invention has the following properties:

Spellcasting Focus. You can use the Unstable Invention as a spellcasting focus for your Artificer spells.

No Infusions. The Unstable Invention cannot accept Artificer infusions. It is already too unstable to tolerate additional enchantment.

Replaceable. If the Instrument is destroyed or lost, you can rebuild it over the course of a long rest, provided you have access to artisan's tools with which you are proficient.

Fracture

Anomaly Protocols

At 3rd level, the Unstable Invention gains the ability to run Protocols, the procedures by which you channel scarlet radiation into measurable effects. Protocols are fueled by Scarlet Charges.

Scarlet Charges. The Instrument has a number of Scarlet Charges equal to your proficiency bonus. You regain all expended Charges when you finish a short or long rest. Once per turn, you may expend an Artificer spell slot of 1st level or higher (no action required) to regain 1 Scarlet Charge.

Preparing Protocols. After each long rest, you prepare a number of Protocols equal to your Intelligence modifier (minimum of 3) from the Protocol list below. Only prepared Protocols can be activated until your next long rest.

Activating a Protocol. You can activate a prepared Protocol by spending 1 Scarlet Charge. Most Protocols require a bonus action to activate; those requiring an action are noted. Unless stated otherwise, the range is 30 feet and the save DC equals your Artificer spell save DC.

Activating a Protocol has two consequences beyond its listed effect:

1. It applies 1 level of the Irradiation condition to the target. (See the Irradiation feature.)
2. It triggers a roll on the wild magic table, as determined by your DM. The Fracture feature may modify or suppress this trigger.

Protocol Die. The die size referenced in Protocol descriptions is determined by your Artificer level: d6 at 3rd level, d8 at 5th level, d10 at 9th level, d12 at 15th level.

Protocol List.

• Inspiring Reading (bonus action). An ally within range gains one Protocol die. Within the next 10 minutes, they may roll and add it to one attack roll, saving throw, or ability check of their choice.
• Suppressing Frequency (bonus action). A creature within range makes a Wisdom saving throw. On a failure, it must subtract one Protocol die from the next attack roll or saving throw it makes before the end of its next turn.
• Harmonic Shielding (reaction, taken when an ally within range is hit by an attack). Reduce the damage the ally takes by one Protocol die plus your Intelligence modifier.
• Stabilizing Pulse (bonus action). An ally within range gains temporary hit points equal to one Protocol die plus your Intelligence modifier.
• Recalibrating Pulse (reaction, taken when an ally within range fails a saving throw). The ally adds one Protocol die to the saving throw, potentially turning the failure into a success.
• Kinetic Discharge (action). Each creature in a 15-foot cone originating from you makes a Strength saving throw. On a failed save, a creature is pushed 15 feet away from you and knocked prone.
• Magnetic Lock (bonus action). A creature within range makes a Strength saving throw. On a failure, it is restrained until the start of your next turn.
• Gravity Well (action). Choose a point within range. Each creature in a 15-foot-radius sphere centered on that point makes a Dexterity saving throw. On a failure, a creature's speed is halved and it cannot take the Dash action until the end of its next turn.
• Disorienting Readout (bonus action). A creature within range makes an Intelligence saving throw. On a failure, until the end of your next turn it cannot take reactions, and the next attack roll made against it has advantage.
• Kinetic Vector (bonus action). A willing ally within 30 feet may use their reaction to move up to their speed without provoking opportunity attacks.
• Feedback Loop (reaction, taken when a creature within 30 feet hits you or an ally with an attack). The attacker takes force damage equal to one Protocol die plus your Intelligence modifier.
• Diagnostic Scan (bonus action). A creature within range makes an Intelligence saving throw. On a failure, you learn its damage immunities, resistances, and vulnerabilities, and whether it has taken any damage. The information remains accurate to you for 10 minutes.

Irradiation

Every Protocol you activate leaves its target faintly glowing with scarlet radiation. This residue is represented by the Irradiated condition.

When you activate a Protocol on a creature, the target gains 1 level of Irradiation. A creature can have up to 3 levels of Irradiation at once. Activating an additional Protocol on an already-Irradiated target adds another level (up to the maximum of 3) and refreshes the condition's duration.

Irradiation lasts for 1 minute, or until any of the following occurs:

• The Irradiated creature is more than 60 feet from you at the end of your turn.
• The condition is removed by lesser restoration, dispel magic, or a similar effect.
• You choose to end it on your turn (no action required).

Irradiation is not a concentration effect. You may apply and sustain Irradiation while concentrating on other spells or effects.

The effects of Irradiation depend on whether the affected creature is willing or unwilling. A creature that consents to the condition is considered willing; one that does not consent, or would oppose the effect, is considered unwilling.

Willing creature (ally):

• 1st level of Irradiation: +1 bonus to saving throws.
• 2nd level of Irradiation: +1 bonus to saving throws and Armor Class.
• 3rd level of Irradiation: The bonuses from the 2nd level apply. Additionally, once per turn when the creature hits with an attack, the attack deals an extra 1d4 force damage.

Unwilling creature (enemy):

• 1st level of Irradiation: −1 penalty to attack rolls.
• 2nd level of Irradiation: −1 penalty to attack rolls and saving throws.
• 3rd level of Irradiation: The penalties from the 2nd level apply. Additionally, the first time each turn the creature is hit by an attack, it takes an extra 1d4 force damage.

Irradiation does not stack with itself across multiple Unstable Inventors. If a creature would gain a level of Irradiation from another source while already Irradiated, use the higher level.

Refined Instrumentation

Broadcast Theorem

At 9th level, your Instrument's output propagates further, and you gain greater influence over the phenomena it produces.

Greater Protocol Die. Your Protocol die increases to a d10.

Twinned Protocol. When you activate a Protocol that targets a single creature, you may spend 1 additional Scarlet Charge to have it also target a second creature of your choice within 30 feet of the first. The Protocol's effect applies to both creatures, and each gains a level of Irradiation.

Fallout. When an Irradiated creature within 30 feet of you takes or deals force damage, you may spend 1 Scarlet Charge as a reaction to apply 1 level of Irradiation to another creature of your choice within 30 feet of the Irradiated creature.

Controlled Variables. When a wild magic roll would be triggered by something you did, carried, or activated, you may roll twice on the wild magic table and choose which result occurs. You can use this feature a number of times equal to your Intelligence modifier (minimum of once), and you regain all expended uses when you finish a long rest.

Unified Theorem

At 15th level, your understanding of scarlet radiation is comprehensive, whether or not you have admitted as much in writing. The Instrument's effects reach their fullest expression.

Greater Protocol Die. Your Protocol die increases to a d12.

Integrated Theorem. While you are in the Acceptance stance, any Irradiation you apply is no longer limited by distance and lasts until the end of the current combat.

Cite Your Sources. When a wild magic roll would be triggered by something you did, carried, or activated, you may choose any result on the wild magic table instead of rolling. You can use this feature a number of times equal to your Intelligence modifier (minimum of once), and you regain all expended uses when you finish a long rest. This pool is shared with the Controlled Variables feature from Broadcast Theorem. Your DM may elect to grant each feature its own pool instead.