Quantum Spell-casting (Analogy to explain Vancian magic)

[PhoenixPhyre]

A word of explanation--I'm a quantum chemist by training. As a side-effect (positive? negative? who knows?), I tend to think in physical analogies. The following is the best explanation I've been able to come up with for Vancian magic as implemented in 5e. This is NOT official in any way, and it almost certainly was not the reason for the implementation. It's just a way I found to understand and rationalize it. Caveat--warlocks are weird. Since their abilities come from outside themselves entirely, they don't always follow the rules.


Quantum Spell-casting.
The idea of Vancian casting makes sense—it’s the Pauli exclusion principle/electronic structure theory in action.

In atoms, electrons can be modeled as occupying "orbital shells" of fixed energy (relative to being free). A bare atom that gains an electron loses energy, releasing that energy in the form of light (usually). This is how lightning happens--the extreme electric field rips electrons free from atoms. When they recombine, they give off large amounts of light/heat/sound. Lasers work similarly (but under much tighter control).

The energy of different orbital shells is not linearly related--hydrogen orbitals scale as 1/n2; more complicated systems scale in more complex ways.

The analogy:
Each spell slot is a 1-electron orbital--the meditation/prayer/etc. to regain spell slots is the process of putting the system in a population inversion, creating holes in the lower shells. The deeper the hole, the higher the energy (level). Casting a spell using a certain slot fills the hole corresponding to that slot, releasing the energy to be shaped into a spell.

Slots are different for varying level, but identical for fixed spell level. The difference in energy does not scale linearly with spell level—this explains why a 2nd level slot is not replaceable by two 1st level slots.

Training and experience allow the caster to access deeper (higher level) slots as well as increase the number of holes at each lower spell level. Each level can only hold so many “electrons,” so the total number of slots at any level is capped. Deeper levels can hold fewer slots—just like electrons in an atom.

Spells thus are the patterns used to shape the (otherwise homogeneous) energy coming from expending a spell slot. Different classes learn these patterns differently, thus the differences in casting even though spells are shared between classes. Some learn the skill to "short-cut" the process of restoring a population inversion (arcane recovery and the like).

Rituals use ambient magic to fuel the spell, but thus are slower and require more training to use. Spell scrolls and items that can cast spells store the energy in patterned form (a TV dinner vs a from-scratch meal) but lose flexibility.

Feel free to tell me how badly I've botched the analogy and point out all the corner cases where it doesn't work. Or if it doesn't make any sense at all. Which it doesn't, probably. Quantum mechanics is just strange and you have to be slightly crazy to understand it at all.

[DragonSorcererX]

Your description is really good! You made magic be more sci-fi than psionics... :smallsmile:

[ClintACK]

Nice.

But I doubt you'll persuade any of the chronic "Vancian Magic is Stupid!!11!" crowd.

Prediction: Before page three of this thread, someone will unironically post the claim, "No one has ever come up with a logical explanation for Vancian casting."

Further Prediction: Before page four of this thread, you will be called an "Apologist".

Still, well done. You even make sense of the idea of a multiclass Cleric/Wizard using a shared pool of slots.

[mgshamster]

Casting a spell requires you to move your electron (spell energy) into an excited state, and when the spell energy drops back down, the spell effect is released.

[MrStabby]

And using concentration to cast a spell as a readied action is a metastable state? And a set of casters who cast spells with the condition that their neighbouring caster does the same can form a magic laser?

[Aaron Underhand]

Thank you - I liked the analogy...

In the past I played a lot with a home brewed spell point systems, a base 2n+2 points to cast a spell.

In those universes a x2 spell points wand was both common and useful

Until we met the big-bad with about 180 wands in a toroidal cavern who was building a spell point cyclotron...

In your analogy each person is an atom (or more complex structure) subject to a population inversion. So immediate questions arise about pumping that, and (as already mentioned) a mage-laser.

However I like the possibilities for monsters - that's an energy source to drain/tap into, so a Mage-Wight appeals...

[Sabeta]

I've always imagined Magic as a unique transitive particle. Basically free-flowing ether that operates on a primordial level, and that a magic user can manipulate into the particles and subsequent atoms necessary to produce any effect they want within a localized area.

I've also thought of systems where Magic is a type of particle (I like magic particles) that has the ability to "remember" what it was a part of before, and that casting magic is simply getting space to remember itself in a different form.

[Reynaert]

Casting a spell requires you to move your electron (spell energy) into an excited state, and when the spell energy drops back down, the spell effect is released.

Odd, I would say that preparing a spell moves an electron in an excited state, and casting it moves it back to the ground state (releasing the photon/spell). In the old system that works quite well, in the new system there's the disconnect between preparing spells and having spell slots. Perhaps the spells are some kind of filter that shapes the spell energy?

[mgshamster]

Odd, I would say that preparing a spell moves an electron in an excited state, and casting it moves it back to the ground state (releasing the photon/spell). In the old system that works quite well, in the new system there's the disconnect between preparing spells and having spell slots. Perhaps the spells are some kind of filter that shapes the spell energy?

I think that could work for an older system where practically every spell is prepared. Not all spells are prepared in this system, so I feel that it's more appropriate to excite the electron at the time of casting, like fluorescence.

Or it could be both, and that's the difference between prepared spells and spontaneous spell casting. :)

[Drackolus]

This is pretty good! My complaint with Vancian magic is more of a game design one (I just feel it needlessly complicates the whole thing). Still, I like this explanation.

[JackOfAllBuilds]

I've always imagined Magic as a unique transitive particle. Basically free-flowing ether that operates on a primordial level, and that a magic user can manipulate into the particles and subsequent atoms necessary to produce any effect they want within a localized area.

I've also thought of systems where Magic is a type of particle (I like magic particles) that has the ability to "remember" what it was a part of before, and that casting magic is simply getting space to remember itself in a different form.

I think you pretty much described the Weave of Mystra, in the Forgotten Realms.

Now I'm thinking of magic as wave functions and interference patterns...

[Sabeta]

I like the second explanation a little bit more, even if it's less scientific. (Actually, thinking on it a bit more; the two explanations are not incompatible). It allows you to also rationalize all kinds of game abstractions, for example gaining experience from killing a monster is now absorbing its memories of combat. It can also explain ghosts whose particles simply remember being alive, and so many more fun things.

I am not familiar with the Weave of Mystra though. 5e takes place in the Forgotten Realms doesn't it? I began in 4th edition, but I don't know what module I played. All I know of D&D is pretty much just the Sword Coast. Farthest east I've been is Redlarch I think.

[mgshamster]

I am not familiar with the Weave of Mystra though. 5e takes place in the Forgotten Realms doesn't it? I began in 4th edition, but I don't know what module I played. All I know of D&D is pretty much just the Sword Coast. Farthest east I've been is Redlarch I think.

You can read a bit about the Weave on page 205 of the PHB.

[PhoenixPhyre]

Odd, I would say that preparing a spell moves an electron in an excited state, and casting it moves it back to the ground state (releasing the photon/spell). In the old system that works quite well, in the new system there's the disconnect between preparing spells and having spell slots. Perhaps the spells are some kind of filter that shapes the spell energy?

In the analogy I presented, spells and spell slots are completely different things. Spells are patterns, slots are energy sources. A spell is like a circuit--the spell slot is the generator that supplies the electrical energy.

In the physics, the recovery of spell slots is the part where the "electrons" get raised to excited states. It's actually the holes (where the electrons were) that allow for energy release (as a bound electron has negative potential energy relative to the free state). Hence the population inversion: more electrons are in higher states than in lower states. Casting a spell allows one "electron" to drop into a selected hole, releasing free magical energy that is channeled into a spell circuit.

I envision spells as setting up a resonance condition with the universe around it, causing the effect. This allows comparatively small amounts of energy from the caster to control much larger amounts of energy in the effect (ie fireball). That's why we don't have to worry about spell-casters exploding if they're bumped wrong and the holes spontaneously fill :smallsmile:

Non-concentration spells are fire-and-forget--the resonance is established and the effect happens but either is self-sustaining (aid, mage armor) or isn't persistent (fireball). Concentration spells require active maintenance. Possibly, a creature with two independent brains could focus on two spells at once (4e spellweavers). Would split personalities be enough? Hmmmm...