Not Your Average Pyromancer: A 5e Wizard Tradition

I’m taking a class on thermodynamics, and just finished one on quantum mechanics. The physics is really cool, but what stuck with me was this XKCD comic that conveniently came out a month ago:

Then I thought: you could make a wizard out of this. So here it is. A (sub)class inspired by a class.

Wizard Tradition: Thermodynamics

A woman writes on a slate with a piece of chalk, arranging equations beside a simple graph. Calculations complete, she casts the symbols into the air. The world bursts into flames around her.

A man steps out of the way of a spear thrust. He snaps his fingers and holds his breath. His armored opponent collapses to the ground, gasping for breath.

A professor scrawls on the board as they speak to their class. “Always remember the three laws,” they say. “You can’t win. You can’t break even. And you can’t stop playing.”

You are a diligent student of thermodynamics: the school of heat and work, of paths and histories. Practitioners of thermodynamics have a high mortality rate, for their magic trades in the fundamental forces that govern the world. A “heat mage” uses their spells not to rewrite reality, but to push it forward along inevitable paths.

Level 2: Heat Flow

$$dU = SdT-PdV+ \sum_i^n \mu_i dN_i$$

Your spells are those that govern heat and work. You learn the following spells upon gaining access to the listed spell levels, in addition to the normal spells learned by leveling up. If they are not Wizard spells, they count as Wizard spells for you. Other wizards may not copy these spells from your spellbook; the formulae are too esoteric.

Spells marked with an asterisk (*) are described at the end of this document.

Level 2: Maxwell Demon

$$\displaystyle S = \oint\frac{q_{\text{rev}}}{T}dT = k \ln \Omega$$

You always have the spell Unseen Servant prepared. It does not count against your prepared spells. When you cast the spell Unseen Servant, you may instead order it to sort particles in a 10-foot cube. The servant may not sort particles that are part of a greater whole, such as the atoms and molecules that make up a living creature, nor may it physically change the particles. If you cast Unseen Servant using a spell slot of higher than first level, you may direct the servant to sort an additional 10-foot cube per spell level.

Level 6: Assume Ideal Conditions

$$\Delta N = 0, q = q_{\text{rev}}, PV=NRT$$

You know how to simplify problems in ways that still describe reality. You may add twice your proficiency bonus on Arcana and Investigation checks.

Level 10: Perfect Partition

$$q_{\text{sys}} = -q_{\text{surr}}, w_{\text{sys}} = -w_{\text{surr}}, S_{\text{tot}} = S_{\text{sys}} + S_{\text{surr}}$$

You can magically separate the world into a system and its surroundings. When you cast a spell with that targets an area, you may reshape the area of the spell as you wish, so long as the total area remains the same.

Level 14: Entropic Decay

$$\Delta S_1 < \Delta S_2 \implies 1 \to 2$$

You have learned to reshape your spells purely in terms of entropy. When you cast a spell that would deal fire or cold damage, you may instead change the damage type to force. You may make this decision when you cast the spell.

Thermodynamics Spells

Adiabatic Compression

2nd-Level Transmutation (Thermodynamics)

Casting Time: 1 action

Range: 150 feet

Components: V, S, M (an iron bead)

Duration: Instantaneous

You compress gas by a factor into a small space around the target point, creating an implosion of heat and pressure. Each creature inside a 10-foot sphere must make a Dexterity Save or take 3d6 fire damage + 2d6 bludgeoning damage, or half as much on a successful save.

At higher levels. When you cast this spell with a spell slot of third level or higher, the fire damage and bludgeoning damage increase by 1d6 each per spell level above second.

Isochoric Heating

4th-Level Transmutation (Thermodynamics)

Casting Time: 1 action

Range: 100 feet

Components: V, S, M (a glass vial of mercury)

Duration: Up to 1 minute (concentration)

You alter the temperature within a 30 foot sphere. Choose either heating or cooling: if you choose heating, this spell deals fire damage; if you choose cooling, this spell does cold damage. On the first round, the spell deals 2d6 damage. Every round thereafter, damage increases by 1d6, up to a maximum of 5d6 damage per round. You may choose to move the sphere to another location within range, but this resets the damage counter.

At higher levels. When you cast this spell with a spell slot of fourth level or higher, the radius of the sphere increases by 5 feet per spell level.

Entropic Shunt

5th-Level Transmutation (Thermodynamics)

Casting Time: 1 reaction, taken when a creature you see makes an attack roll or starts to cast a spell

Range: 300 feet

Components: V, S, M (an hourglass filled with water)

Duration: Instantaneous

You target the triggering creature, which must succeed on a Wisdom saving throw or freeze as entropy reverses around it, causing the attack to miss or the spell to be wasted. At the start of its next turn, the target unfreezes and is sickened. While frozen, the target is considered helpless.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, you can target one additional creature for each slot level above 5th. All targets must be within 30 feet of each other.

Pseudokinetics

6th-Level Transmutation (Thermodynamics)

Casting Time: 1 action

Range: 150 feet

Components: V, S, M (an ampoule filled with two distinct gases)

Duration: Instantaneous

You reave though potential barriers, instantly forcing a process to occur in an instant. This can be as simple as lighting a fire or as grand as evaporating a lake, so long as the target can fit within your line of sight. If cast on a creature, the target must succeed on a Constitution Save or it takes 14d6 force damage and suffers one level of exhaustion. On a successful save, it does not suffer exhaustion and takes only half damage.

Quantum Tunneling

6th-Level Transmutation (Thermodynamics)

Casting Time: 1 action

Range: self

Components: V, S, M (a lead pendulum)

Duration: up to 1 hour (concentration)

You destabilize your waveform, stretching it beyond the classical potential barriers and into the aether. While you maintain concentration, you can appear at any point within 150 feet that you can see. Additionally, attacks against you are made at disadvantage because of your truly uncertain position. This is not negated by true sight.

Wavefunction Collapse

8th-Level Transmutation (Thermodynamics)

Casting Time: 1 action

Range: 150 feet

Components: V, S, M (a set of engraved calipers worth 500 gp)

Duration: 1 round or 1 minute (concentration; see description)

You collapse the superposition wavefunction of the target completely, locking them in place across all alternate futures. So long as you concentrate, you may completely dictate the actions of the target. If the target succeeds on a Wisdom Save, the target breaks free of your model after one round instead.