I'm playing with ideas for magic in my world. This is the same world as in A corrupted religion, in case you're wondering.

In the world of {PlaceholderWorldName}, people can perform magic, but it isn't your average run-of-the-mill fantasy stuff.

In essence, users can transfer energy. This involves decreasing the energy of a group of particles (source) and increasing the energy of another group (target). The energy can come from themselves (body heat, moving arms, maybe neural electricity?*), or from any other source of energy (moving air particles, or a hot object). No energy is created or destroyed and the type of energy is conserved (kinetic, thermal, etc). The energy is "transferred" from source to target.

Both the target and source need to be close to the user. For simplicity, I'll define that the user must be touching both the source and the target directly during energy transfer to perform a spell (one with each hand). No damage will occur from this, since none of the energy is directly transferred to the hands.

The only magic involved is the selection of source and target, and the transfer of energy. All of the results from spells are purely scientific.

This allows users to use "ingredients" to cause chemical reactions, channel energy from a large source to super-heat a small target, or vice versa to cool. They can also move or suspend objects, and harness things like lightning.

I expect I will have many questions stemming from this, but I will start with the basic one:

What sorts of simple spells are possible using this system, with scientific explanations?

The elements of magic correspond to the following types of energy:

  • Light

By reducing the light emissions of a light source, the user can cause the target to emit light of the same frequency.

  • Thermal

By reducing the heat energy of any object above absolute zero, the user can increase the heat energy of the target relative to specific heat capacity and other factors.

  • Electrical

By reducing the current flowing through a conductor, the user can apply a current to the target.

  • Kinetic

The user can apply a force to a target, given that an equal and opposite force is applied to the source.

  • Sound

The user can reduce the volume of sound emitted to cause the target to emit sound. The waves cannot be altered, so the target will emit the same sound.

P.S: I'm aware that types of energy somewhat overlap, such as sound being the movement of particles in a medium, but for simplicity magic users must use a source of sound to "create" sound, and a source of movement to move things, etc.

(Note: I have missed out some types of energy which I think a traditional fantasy nation would not consider to be "energy" due to an incomplete understanding of science, or other religious explanations being favored by the majority. These include elastic potential, gravity, Electrical energy is from the weather, or static, since technology as far as steam power has yet to be introduced, let alone electricity.)

*On taking energy from yourself, this brings into account the possible limitations on damage to the user's body. This is a topic for a different question and does not need to be solved here.

  • $\begingroup$ What elements of magic you have in mind? Your list is the list of energy, unless I understand the title wrong. $\endgroup$
    – Vylix
    Commented Aug 4, 2017 at 11:24
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    $\begingroup$ I don't understand the distinction between electric, magnetic or gravitational energy and potential energy. As in, what do you think that "potential" energy is, other than the energy of a body in a electric, magnetic or gravitational field? By "thermal" energy you mean heat? What do you mean by transfer of sound energy? Shouting? Is transfer of "light" energy the same thing as illuminating the target? $\endgroup$
    – AlexP
    Commented Aug 4, 2017 at 11:35
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    $\begingroup$ You say that you dislike "potential" energy, yet the explanation below the transfer of kinetic energy speaks of forces... Force and energy are very different things; to give a simple example, a hook keeping a hat one meter above ground exerts a force on the hat, exactly balancing the gravitational pull of the Earth, but it does not transfer energy to the hat al all. $\endgroup$
    – AlexP
    Commented Aug 4, 2017 at 12:09
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    $\begingroup$ @AricFowler Violating the laws of thermodynamics is pretty overpowered. $\endgroup$
    – sphennings
    Commented Aug 4, 2017 at 13:29

9 Answers 9


What it sounds like, and please correct me if I'm wrong, is that you have a mostly real-to-life physics system with two key modifications:

I'm not gonna lie, that's really, really cool (no pun intended). A relatively simple change, but enormous in its implications.

So conservation of energy is still in effect, and a magic user can't actually convert energy themselves. But with this ability the conversion of energy becomes way simpler to be sure. This is one of the biggest issues we have today even: how do we turn, say, the chemical energy of gasoline into the kinetic energy of a car? We answered it with the internal combustion engine, but let's look at it from a magic user's point of view.

When gasoline burns, it gives about 48.7MJ/kg of energy. A modern, top-of-the line internal combustion engine gets about 38% efficiency, which lowers the energy of the gasoline to a functional 18.5MJ/kg of energy. But imagine if you could capture all of it with no loss. A magic user from your world would be able to light gasoline on fire can siphon off 100% of the thermal energy being produced. You now have a way to start a fire, melt through rock/metal, or create a thermal breeze, and your magic user needs 1/3 the amount of combustible material the real world would need.

Now lets look at medicine. At our most basic level, all humans are is a series of interlocking chemicals and reactions between those chemicals. Now, if we let the generalization 'chemical energy' apply somewhat ambiguously, then healing spells become quite possible. By simply holding a plant leaf, or a protein bar, or essentially any edible or chemically active material a magic user could channel that chemical energy into repairing damaged tissue. This same principle applies to underwater breathing: all you need is some form of chemical energy and you can break water down to get your oxygen for as long as you want.

How about engineering or construction? Magic user's would be capable of impressive feats of strength: imagine a magical construction site where a boulder or large rock is mounted in a shaft. Whenever something needs to be lifted, the boulder is dropped, a magic user catches it, then slowly transfers the kinetic energy into a huge I-beam to make it lighter.

With thermodynamics out of the way, quite literally anything is possible.


A gun

User holds a tiny, dense object in one hand (even a grain of sand could work), and a bigger, heavier object in the other. User throws big object upwards with ordinary muscle power. When the object falls upon user, user transfers its kinetic energy into the small object. User is unharmed by the (now stopped) falling object, smaller object flies out very quickly. If user catches the big object in the same throwing hand, and is holding more tiny dense objects in the other, user is ready to cast the spell again.

This spell is simple and highly scalable: with an increasingly small and dense target, and an increasingly fast and heavy source, it is possible to give the target speeds amounting to significant fractions of C.


User redirects incoming energy of all types to a pebble or piece of dirt stuck on the underside of their shoe. This can be sustained indefinitely, if user can purposefully avoid transferring the thermal energy of the air that is being touched and breathed.

All conventional methods of warfare would be rendered obsolete by this simple spell; melee, chemical and biological warfare would become the most viable alternatives.

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    $\begingroup$ I'd regard this as a very good answer - except... No. I regard this as a very good answer. +1 . You can study the help center, to further figure out how we work. See you around. $\endgroup$ Commented May 11, 2019 at 2:57

Young mages must be taught to keep their targets large and their sources small. For the world is fragile on the smallest scale...

Take all of the light in a well lit room and focus it into the eyes of your opponent. They will probably never see again.

Focus the warmth of a sunny day into a single grain of sand, add the pressure of the whole sky above you and a mushroom cloud will mark your passing from this world.

There are individual, life critical nerves in every human body which could be scorched beyond function by less electricity than is generated by dragging your feet across wool carpet on a hot dry day.

The secret to living long enough to learn magic, is to think big when choosing targets.

  • $\begingroup$ Perhaps there could a limit on the size, or mass, of the target and source? $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 14:17
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    $\begingroup$ I think that would be wise. A mage's domain (the size of the targets and sources which she can tap) grow in inverse ways. When young and weak, a mage can only tap small sources and target large destinations. As she grows and learns better concentration (for gathering from sources) and how to focus (for isolating smaller targets), she become more powerful and dangerous. $\endgroup$ Commented Aug 4, 2017 at 14:29
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    $\begingroup$ A show of how powerful you are could be the ratio in mass between your source and target! That's an amazing idea! $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 14:30

Magic is weird, because possessing even "modest" magic enables all sorts of miraculous outcomes.

For example, you say that magicians can transfer "light" energy, whatever you believe that to be. Then they could banish darkness from their cities by simply transferring a small amount of luminous energy from the day site of the planet to the night side; the illumination provided by lightbulbs is hundreds of times weaker than the illumination provided by the sun at noon; nobody will notice the slight decrease of the light of the day (not even photographers), and yet it will make a tremendous difference at night.

The transfer of "thermal" energy is even more wonderful. You can make a nice (almost) perpetual motion machine in this way. Just take a plain cylinder with a piston in it, and transfer thermal energy from the ocean (or from the Sun, or from Betelgeuse) to the air inside the cylinder; the air will expand, pushing the piston; evacuate the air, reset the position of the piston, repeat: you have a motor. And refrigerators are even easier, obviously. The magician can extract water from the air in the middle of the desert by transferring thermal energy from the air to Pluto: water will condense and fall as rain.

The transfer of kinetic energy is quite a bit more complicated, and it will play havoc with the physics of your world. You see, in our physics kinetic energy isn't necessarily conserved, but momentum is. Now, imagine that you have a nice moving mass of air, what is usually called wind, and the magician transfers some of the kinetic energy of that mass of air to, say, a ship. The speed of the wind cannot decrease, because of the conservation of momentum, and neither can the speed of the ship increase, for the same reason; yet, somehow, energy is conserved by the particular brand of magic you propose... The consequences are interesting.

Now, both sound and light are waves. They carry energy, true, but they also have a wavelength and a phase. What happens with the wavelength and phase when you transfer the energy? Interesting.

  • $\begingroup$ okay, so what if i limited the range to a few metres, or even to within touching distance of your hands? Also, I said that you cannot change the wavelength of the light used, and cannot change the sound that you use (meaning the waveform is preserved). $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 12:10
  • $\begingroup$ You just described a Stirling Engine which runs on the simple principle that one end is hotter than the other. I don't believe anyone has previously accused it of being a perpetual motion machine though. $\endgroup$
    – Separatrix
    Commented Aug 4, 2017 at 12:45
  • $\begingroup$ @Separatrix: All thermal engines work on the principle that one end is hotter. But, you see, the Stirling engine needs a hot source and a cold source. With magic, you don't need a hot source, which means that you can use all the enormous thermal energy of the ocean... $\endgroup$
    – AlexP
    Commented Aug 4, 2017 at 12:54
  • $\begingroup$ It doesn't need a cold source, it just needs a differential. $\endgroup$
    – Separatrix
    Commented Aug 4, 2017 at 13:04
  • $\begingroup$ @Separatrix: A differential temperature is exactly the meaning of requiring a hot source and a cold source; a thermal engine works by moving heat from a hot / warm / warmer source to a cool / cold / colder source and in the process tapping some of the energy flow and converting it into mechanical energy. $\endgroup$
    – AlexP
    Commented Aug 4, 2017 at 13:09

To compare your magic system with other magic systems, I tried recreating classic spells with it:

  • Fireball: Hold some sand or dust (gunpowder works best for obvious reasons) in one hand, then jump, and as you land, transfer into the dust all of your kinetic energy as well as a ton of heat from the surrounding air (or, if there are limits on how much heat can be transferred from air, you'll need a hot coal or something as an additional component). This should launch a sizable explosion.
  • Invisibility: Absorb all the light hitting your body and convert it into identical light leaving your body. If you do it precisely, you will be completely invisible. I suspect that it would take a ton of practice, and maybe only expert mages could do it, while beginners would just seem to glow or turn random colors.
  • Levitation: I don't see why you can't take your kinetic energy from falling and transfer it into a flywheel or even the air around you, thus keeping you hovering in midair. Incidentally, mages should just carry flywheels around with them everywhere, since they can jump a few times to "charge" them and then use the kinetic energy in them as a source for super strength (flywheels also help your range for the fireball spell I mentioned earlier).
  • Fly: A natural extension of the previous spell, but it's quite limited. You can hover in place easily, but actually moving requires you to have a source of large amounts of kinetic energy on hand. The best way I can think of to fly is to start on a high cliff or building, you can jump off and, by funneling energy back and forth from the flywheel, change your direction of motion. An interesting consequence is that you can never fly higher than where you jumped from, since that would require too much energy. However, you should be able to glide laterally for long distances, and have good maneuverability if you can transfer the energy back and forth fast enough.
  • Lightning Bolt: This takes way more electrical energy than is feasible unless you have a car battery on hand as a magical component. Stick with fireballs.
  • Ray of Light: Hold a lens and move all of the light energy hitting you through it. If the mage makes sure that the light goes in straight, it should produce a fairly effective long-ranged attack at the focal point. A more experienced mage might be able to make the light they transfer hit at an angle that changes the range, but I imagine it would take serious practice to be able to use this in battle. Again, Fireball (or the gun trick mentioned by Anonymous) is a more effective battlefield spell.
  • Chill Touch: Among all the awful things a mage could do if they got within touch range of an enemy is simply drain all the heat from their body. Bonus points if you freeze someone to death with a touch and simultaneously use their body heat to shoot another guy with a fireball.
  • Shield: A cool trick for a mage in a tight spot. They can focus on their cloak, transmitting all energy it receives into their flywheels or the ground. This works well for swords and the like, but if they can't dissipate the energy too quickly (a bullet or arrow hits faster than human reaction speed) then for ranged attacks they could use...
  • Control Water: Touch a large source of water. A river or waterfall, whether natural or man-made, is best so that you also have plenty of kinetic energy on hand. Use that to move the water in midair in whatever formation you like, keeping your hands in contact with part of it, and siphon off its energy as it starts to fall to keep it hovering. With this, you can create elaborate shields that will stop most ranged projectiles. If your source of energy is continuous (like a river), you could channel it into the water and make it deform and hit or cut enemies. Basically, waterbending.

Things your magic system probably doesn't do: Teleport, Charm Person, Summon Monster, Transmutation.

Final, unrelated note: if the planet in your setting rotates, DO NOT let your mages siphon energy from it. It makes them way too powerful, and eventually they'll overuse it and the world will stop spinning and it'll kill everyone.


Simple transfer-energy spells

  • Death touch: stopping the heart of any person by transfering its kinetic energy to the rest of their body in uncontrollable spasms. A trained magic user would be however able to prevent that.
  • Kinetic wrestling: boxing magic users could use energy transfers to trip an opponent trying to hit them, by transfering the energy of attacks to the surrounding air in bursts.
  • Alchemical transformation: realign the target's chemistry and create new chemical bonds as desired by burning the source. Using a single object/material as source and target would allow one to modify it by burning off surplus material and transferring the created energy to the core of the object.
  • Crafting weapons/items: by transferring the chemical and thermal energy between parts of an object one could burn and dissassemble while hardening or cooling other parts to create weapons, extra energy could be drawn from the ground or air.
  • Light: transferring heat from one's body to a small piece of wire would cause it to begin to emit light, although this would only be a heat transfer.

For a "scientific" explanation this kind of magic would require the energy for the "energy transfer" to actually be powered from some occult source, a kind of nation-wide energy bank, accessed for instance by creating energy conduits such as magic circles, or wearing garments/tattoos allowing one to draw from this common resource. What you are describing by the way is the magic system in the Fullmetal Alchemist world.

  • $\begingroup$ I've never played Fullmetal Alchemist... maybe I should. By the way, death touch requires you to touch their heart and cutting them open would do the job for you anyway? $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 14:40
  • $\begingroup$ @AricFowler Since you can feel a persons heartbeat and the kinetic energy of the heart is directly pushing against the circulatory system, my assumption was that one would be able to transfer energy from source as a whole object. But if not, then one could definitely immediately stop blood flowing through veins closest leading to explosive bleeding. Guess this is up to the original author to decide. $\endgroup$
    – 8DX
    Commented Aug 4, 2017 at 14:47
  • $\begingroup$ agreed. perhaps that's why mages don't like to be touched, and wear clothes that cover their skin... $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 14:54
  • $\begingroup$ @AricFowler I didn't realise you were the author, but Fullmetal Alchemist is primarily a manga and two anime series and explores these principles a lot, although it seems to allow for much more dramatic exchanges of energy than your system (with experts on specific types such as "fire alchemists", "iron alchemists"). en.wikipedia.org/wiki/Fullmetal_Alchemist $\endgroup$
    – 8DX
    Commented Aug 4, 2017 at 15:07
  • $\begingroup$ oh right, i've only heard of the Square Enix games before $\endgroup$
    – Aric
    Commented Aug 4, 2017 at 15:18

Basically Anything Because...

You'd Violate the laws of Thermodynamics

You'd violate the second law, because you'd be able to move heat from a cold object to a hot object without an sufficient input of energy.

By violating the second law, you can do an infinite amount of work. Simply create a heat engine. A heat engine is something that does work from heat flowing from a heat reservoir to a cold reservoir. You can set the world as your cold reservoir, and continuously move energy from the cold to the heat reservoir.

You'd also violate the conservation of energy

Here is an interesting thing to do. Remember that the conservation of energy only applies to within a inertia reference frame. You can use this to create energy.

In your stationary reference frame, have 2 very large blocks side by side not moving, with a middle lane in between them where you can run, and where you can touch both at the same time. Currently, they have 0 kinetic energy.

Run in between them. In your new moving reference frame, you are actually stationary, while the blocks are moving toward you, meaning they have kinetic energy. Move the kinetic energy of one block to the other completely. Now, in your moving reference frame, one block is stationary, while one is moving past you much faster. Stop running.

Now, in your stationary reference frame, Both blocks are moving in different directions, and their total kinetic energy is non zero.

Ultimately, it depends on your understanding of Science

But basically, you can do anything. Even if you say you can't transform the type of energy, you actually can. Attach a piece of string to the Earth, and hold on to it. If the sun is directly above you, transfer the gravitational potential energy you have with respect to the sun to the Earth. What this means is that you will be moved closer to the sun (aka, you are now flying). If the energy transfer/second is not infinite, this means you are now moving upwards at a certain velocity. Aka, you now have kinetic energy (and I'm pretty sure you created it out of nowhere too). By transferring gravitational energy with respect to the billions of celestial objects, you can basically have free flight.

You can kill someone by transferring their biochemical energy elsewhere. You can transmute things by transferring nuclear potential energy. You can probably collapse a building by moving gravitational potential energy of the ceiling to the floor. Just like how you can fly, you can lift things. You can create a vacuum, by transferring heat energy out of air, and thus making them into liquids. You can move the mass energy of one object to another, with unknown consequences.

Ultimately, you can do almost everything. I haven't thought of a way to destroy the Earth yet, but I'm pretty sure it's doable.


Just wanted to add, windy storms will probably be a mage's best friend. They are basically giant reservoirs of free kinetic energy. If a mage encounters an army during a storm he could just transfer a tiny bit of the energy in the wind into the ground below their feet to make it explode.

Also by moving all of the thermal energy, you could freeze everything in one area while incinerating another.


Stand on a boulder as it's being pushed off a short drop. Direct the kinetic energy into literally anything else you're touching. Maybe take all that energy from the big rock and channel it into a small rock. Big rock goes slow, small rock goes fast.


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