Hot Blade

A hot blade is an edged weapon that somehow heats up, adding the thermal energy of its temperature to the kinetic energy of its blow to achieve Absurd Cutting Power. When active, it will usually glow visibly (without losing any of its structural integrity, somehow) because Power Glows.

Compare Vibroweapon, which uses extremely rapid vibrations instead of heat to enhance its cutting power. A more advanced weapon is the Laser Blade, where the blade is made of Pure Energy instead of just adding (heat) energy to a physical blade. Hot blades are more common in a Science Fiction setting. Its more fantasy-oriented counterpart is the Flaming Sword; a hot blade retains a touch of Playing with Fire while requiring less Willing Suspension of Disbelief.

Usually used with swords, but other bladed weapons are also seen occasionally. A subtrope of Absurd Cutting Power. Unrelated to the idiom "like a hot knife through butter"... though hot blades may, indeed, cut through things in such a manner.


Anime and manga

Fan Works

  • Optimus Prime from the Transformers movies uses some of these to cut Decepticon's heads clean off.
  • In the first Pirates of the Caribbean film, after Will uses his sword to jam the door of the smithy and cut off Jack's escape route, he grabs a replacement out of the forge. It looks impressively glowy but doesn't last very long; fortunately there are plenty more on the racks.
  • The Hitchhikers Guide To The Galaxy has a throwaway gag about a knife that toasts bread while slicing it.
  • In The Wolverine The Silver Samurai was able to cut Wolverine's admantium-coated claws with a superheated Adamantium sword. Since Adamantium suffers from a Like Cannot Cut Like rule, presumably the intense heat melts the claws off.

  • The Warpsword of Khaine from Malus Darkblade is said to feel like it just came out of the forge, and it burns whatever it hits.
  • In Codex Alera many of the High Lords firecraft their swords, because a bleeding wound can be watercrafted better easily enough, but a cauterized wound is unhealable. Since this causes their swords to shine brightly, they also use them to send signals and challenges that can be seen across the chaos of a battle.

Live-Action Television
  • In Supergirl (2015), Vartox wields a red hot axe that can cut a Kryptonian. Ironically, Supergirl destroys it by blasting it with heat vision until it can't take the strain and explodes.

Tabletop Games
  • Many Warhammer swords (at least in the way they are visually depicted), both Warhammer Fantasy (Archaon) and Warhammer 40,000 (THE GOD-EMPEROR OF MANKIND), even when some flames might flicker depending on the artist, verging into Flaming Sword territory.
  • Mutant Chronicles.
  • Call of Cthulhu supplement Cthulhu Companion, adventure "Valley of the Four Shrines". The East shrine is dedicated to Cthugha, a deity made of fire. A sword found in a secret room can be made to glow yellow-hot, which will do damage to creatures vulnerable to fire.
  • Exalted: A Malfeas charm turns a blade too burning hot to be wielded, forcing your enemy to either drop it or suffer lethal damage. Another version of this charm targets armor instead... and it's not easy taking off your armor during a (heh) heated battle.
  • And of course Dungeons & Dragons is full of these. As well as (among others) lightning and cold versions. Not restricted to bladed weapons, though...

Video Games
  • The Heated Cosmic Knife from the Dead Money expansion of Fallout: New Vegas is this. It's an indestructible Absurdly Sharp Blade that has been heated with a heating pad and apparently retains its heat for a ridiculous amount of time, giving it even more destroying power.
    • There is also the Saturnite Fist in Old World Blues dlc. Just give it to the crazy toaster in Big MT and it will become the Saturnite Fist Superheated which glows red hot and sets enemies on fire. A wonder how you don't burn your own hand while wearing it.
    • The base game has the Thermic Lance.
  • One of the bosses from Chrono Cross uses a Steampunk version (a Nigh Invulnerable, Humongous Mecha), but this is technically a fantasy setting.
  • The (in)famous Pyrotechnic Axes in Arcanum: Of Steamworks & Magick Obscura presumably work this way. They're one of the strongest weapons in the game, assuming you're a melee-based technologist.
  • Strider Hiryu's Cypher uses plasma to achieve this effect.
  • Nero's Red Queen from Devil May Cry 4 has a special mechanism inside it; the sword has a gasoline fuel inside, and the sword can be revved; when doing so, it sprays out the fuel to the blade as well as igniting it, making the blade glow hot red.
  • Though they are not technically swords, the hooks thrown by Spider Splicers in the BioShock games are glowing red hot. They are probably heated by plasmid use on the part of the splicers.
  • The Thermic Lances in X-Com 2 are a combination of Hot Blade and Vibroweapon, and are pretty effective against the Demonic Crabs. note 
  • The Omni-blade in Mass Effect 3, the hologram is so the user doesn't accidentally burn themself.
  • In Metal Gear Rising: Revengeance, LQ-84-series UGs can throw superheated knives that are able to penetrate (and partially melt) stone and metal. Perhaps notably, Sam's sword also has a distinct red blade but isn't a Hot Blade; just an exceptional Vibro Weapon. Sundowner's weapon also seems to count, as visible heat and steam can be seen as he slowly slices across the President's neck in the intro
  • A variation from Half-Life 2: an electromechanical crossbow that launches red-hot rebar rods.
  • Warframe has the Heat Sword, Heat Dagger, and Dual Heat Sword (sword+dagger combo), which do fire damage on some of their special attacks. All of them have visibly red-orange blades with glowing segments.
  • In Super Robot Wars Compact 2, the Alt Eisen carries a "Heat Horn" mounted on its head and functions like the Heat Hawk of the Zaku II. When it's rebuilt and upgraded into the Alt Eisen Riese, the weapon is turned into the "Plasma Horn", with an additional feature of Shock and Awe.
  • Sol Badguy's Fireseal(and it's upgrade, Junkyard Dog) allows him to channel his flame powers better. It also allows him to cut with it, despite the blade part being a blunt rectangle.

Western Animation

Real life
  • Sufi tortures a 16-year-old boy with hot knives in order to "exorcise" him.
  • Heated blades have been used for crude amputations to cauterize and disinfect the wound.
  • Actually not a good idea in real life, even if it were feasible; as any blacksmith or metalworker can attest, steel loses its hardness the closer it gets to its melting point. It'd take some very special metallurgy for the material to both glow white-hot and still be viable as a hard cutting edge.
  • There once was a practice called "Blood Tempering," in which a red-hot blade is inserted by stab-wound and/or anally into a slave or prisoner of war, as it would cool the sword at body-temperature. This supposedly made the blades much stronger, and always killed the stab victim in practice.

Alternative Title(s): Like A Hot Knife Through Butter