I want to use Teslapunk weapons in my semi-realistic science fantasy RPG that behave somewhat like flamethrowers, in the aspect that they fire out a branching arc of raw electricity. It would obviously use batteries, cells, or something else instead of traditional fuel that flamethrowers use.

How would these compare to flamethrowers? According to AlexP, batteries have a much lower energy density when compared to gasoline. I would think that death by electrocution would be more humane in terms of pain than that of death by burning. I'm not fluent when it comes to electricity in scientific terms, so it's maybe far worse than a simple flamethrower.

I was inspired by this thread here, that asked about plasma and laser based weaponry.

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    $\begingroup$ The energy density of the best available batteries is about 8 to 20 times smaller than that of gasoline (depending on whether it is computed per volume or per mass), so it is not obvious at all that "batteries/cells would last longer than the fuel of a flamethrower"... And you may want to explain a bit what a "cone of electricity" is supposed to be. $\endgroup$
    – AlexP
    Mar 23, 2019 at 21:18
  • $\begingroup$ It basically fires out a branching arc of electricty, that zaps anything in its path. $\endgroup$ Mar 23, 2019 at 21:25
  • $\begingroup$ Assuming room-temperature high-power superconductors and ultrastrong material, you can easily reach the same energy density than gasoline for batteries. Of course, those two techs will have somewhat game-changing impacts elsewhere, so use those carefully. $\endgroup$
    – Eth
    Mar 25, 2019 at 10:21
  • $\begingroup$ You have misconceptions about flame throwers. Targets suffocate usually long before they burn to death. Additionally a large number of enemy combatants surrenders when encountering a flame trower, as it has a strong psychological effect. google.com/amp/s/taskandpurpose.com/bring-back-flamethrower/amp $\endgroup$ Mar 26, 2019 at 5:51

5 Answers 5


Are handheld flamethrower like electrical weapons realistic? No not at all. Flamethrowers have a simple purpose, they're area denial weapons. The fill a trench or bunker, making it impossible for the enemy to remain there. Even if you block the flames it burns away the local oxygen. Your electrical weapons will completely fail at this job. So what's left is a short range weapon that can kill in a wide path. There it will compete with a shotgun (with a duckbill barrel).

It serves no practical purpose unless it's about overloading some sort of mechanical contraption. If it's about killing people they're not realistic. Electrocution isn't more humane then burning alive. I'd argue it's the other way around. Electrocution cramps up your muscles. Either you get a heart attack or you cook from the inside out. It's not a pleasant way to go.

Now neither is burning alive but something that happens rather fast with burning alive is your nerves burn away. Within seconds the outer layer of nerves is destroyed beyond having the ability to signal pain. While it's utterly distressing to smell yourself burning. To feel your skin tighten and crack. It doesn't hurt as much, the painful period has already passed.

Regardless of that your weapons lack a realistic purpose. They're cool but not realistic.

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    $\begingroup$ They likely won't even compete with a shotgun. The current will take the past of least resistance, if you assume the weapon is at a meter height, for everything more than a meter away the shortest path is directly into the ground. $\endgroup$
    – Whitecold
    Mar 24, 2019 at 8:32

I agree with most of what Mormacil said but differ on a few points.

With enough power (Volts*Amps) then it could instantly kill someone, so it would be humane. The effects would be as, if not more, grisly than a flame throws since with enough power you could vaporize their innards causing them to split open like a potato in the microwave.

For a Tesla weapon to be useful, there would need to be a strong magnetic field to confine the electrons to travel in a specific direction. Otherwise, the arc generated by the weapon would seek the nearest ground potential -- read as dirt, water, walls. But with a helical magnetic field radiating from the weapon towards the target, the electrons in the arc would be confined by a Lorentz force.

This would also provide means of defending against the weapon, powered iron would cause the magnetic field to be distorted in wild ways, making the aim unreliable.

Conductive fluids like salt water sprayed in the air would attract the arc and dissipate some of its energy be being turned into steam, rendering the arc less dangerous.

Any conductive and grounded metal would act as a lightning rod and pull the arc towards it. So a shield or a suit of armor that was grounded would protect the wearer until the metal got too hot as the arc melted a hole through it. But, thick enough and sufficiently grounded metal could last indefinitely.

And lastly, as pointed out in previous answers, battery technology used in laptops and cell phones would not have the power density required for a dangerous weapon. But, a fuel cell and one-use chemical batteries used for missiles generate tremendous power for the length of the weapon's flight time -- 20 minutes to 2 hours. These kinds of batteries are called primary cells.

It is not unreasonable to think that either of these power sources could be used. Fuel cells would require refueling. And chemical batteries only last for a specific time period after activation. Activation, in this case, means mixing the chemicals. Both aspects provide interesting limitations for gaming.


This probably should be a comment instead of an answer but if you go by the "flame throwers are area denial weapons" logic, we can assume you want a battery powered area denial weapon instead of a literal electric flame thrower and that is doable. And such weapons are in use or testing IIRC even.


A microwave frequency laser. When it hits something with lots of water, human body for example, it makes the water heat up. This causes the nerves in the skin think you are on fire. So this is actually surprisingly close to electric flame thrower in that it fairly effectively simulates one with good energy efficiency and low collateral damage.

Still the good energy efficiency still doesn't really allow "hand held" weapons and it is fairly easy to protect yourself from as the microwaves will not penetrate lots of cheap and easily obtainable things.

IIRC this has been tested but I do recall seeing the actual results.

IR lasers

These are used to blind people. Add small rotating mirror, camera, processor, and a program that directs the laser at moving targets within the field of view and you have an area denial weapon. I think modern software fairly reliably recognizes the eyes even.

I've been toying this idea for a while and I think it might be a feasible short range weapon. Being blinded is very distracting and the energy needed is fairly low. So using one when assaulting or receiving an assault might make sense.

Again the low powered nature means it is fairly simple to protect your eyes if you are expecting this and have the time and resources to prepare. And you would not carry it in your hand, your hand would carry a gun, this toy would strap onto your shoulder.

Blinding lasers are used by military forces but in far longer ranged and non-automated version not the fancy smart short range version here.


Electric weapons basically won't work as you describe (like a flamethrower). Electricity requires a conductive path to its target. (Even static electricity, like lightning bolts, which create their own path to the "nearest" oppositely-charged point.) A weapon that just creates a high, lightning-like charge is most likely to hit you :-)

So you have two possibilities. Either you use a Taser-like mechanism that shoots a thin wire to the target, or you make it a contact weapon like a cattle prod or stun gun.


Combine your electrical charge weapon with a particle beam.

The problem with a bolt of electricity is that it will seek the quickest path the ground in the vicinity. That might be your target, or a tree, or you. How to make sure that your target is the quickest path to ground for the electrical charge, which is presumably coming from your backpack of batteries?

First shoot a proton beam at your target. Protons can be calibrated to drop their energy at a specified distance from discharge. This makes them useful for radiation therapy too.


On the contrary, the proton is a heavy and charged particle that gradually loses its speed as it interacts with human tissue. It is easily controlled and delivers its maximum dose at a precise depth, which is determined by the amount of energy it was given by the cyclotron (via acceleration), and can go as far as 32 cm. The proton is very fast when it enters the patient’s body and deposits only a small dose on its way. The absorbed dose increases very gradually with greater depth and lower speed, suddenly rising to a peak when the proton is ultimately stopped. This is known as the Bragg peak. The behavior of the proton can be precisely determined and the beam can be directed so the Bragg peak occurs exactly within the tumor site. Immediately after this burst of energy, the proton completely stops to irradiate.

Air is a great insulator. In a bolt of electricity, the electrical charge must ionize the air into plasma so that it becomes conductive. In this weapon, your plasma beam ionizes the path and then the charge is happy to take it.

One might protest that if you have a proton shooting particle beam, you could shoot your enemies with that. This particle beam only needs to ionize a hair-thin pathway through the air. Using the beam to deposit energy in your target comparable to an electrical bolt will take a long time, and even then, it might just result in your target getting sick later in the day, or developing cancer some years later.

A cool side effect of this approach - there are free sources of charge to be had. If your target is insulated from the ground but you charge it up with your device, eventually charge might arc across from your charged target to something else in its vicinity. Or you could pull charge down from the sky as a real lightning bolt. One could use the proton ray conduit for exactly this purpose, opening a path between sky and target. The proton ray is invisible and would need to be big to keep the path charged up (or many working in concert) but real naturally occurring lightning bolts are pretty awesome.

That said, you could defend against those too with a portable lightning rod - perhaps a copper spike on your helmet and a trailing cable to ground.


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