09 January 2022


I remember, way back, when I first read about electro-thermal guns for tanks and I immediately figured the technology would be applied to small arms.

I made GURPS stats for them long before GURPS had them for 3e in Ultra-Tech 2 in 1997.  I wonder if I still have the weapons tables in a folder somewhere...  FuzzyGeff printed several copies for my players and me.

Simply, they use a liquid propellant that's excited by electricity to a plasma state to shove the projectile down the barrel.

I also had dual-propellant guns with two stable chemicals that were hypergolic or would only light when an electrothermal impulse was applied.  4e doesn't even have that!

Electrothermal is a modification to the conventional slugthrowers with 1.5 times the damage and range for double the price.  A fair cop!


  1. Solid propellant is far more stable and energy dense than liquids. Space launch likes liquid because it’s throttleable. You can turn it up or down, or off. It’s not very practical for personal weapons. Too volatile, and not as energetic

    1. In electrothermal the energy doesn't come from the liquid. The energy is from it being inducted to a plasma state and that expansion shoving the projectile down the barrel. Something that is basically inert, inducts to plasma readily and has the proper expansion ratio is what we're talking about.

      Dual propellant guns for tanks have been experimented with. I left the world where I would have access to the results a long time ago. But in the following thirty five years, nobody's adopted one. I think we can call that an indicator that agrees with you.


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