Detective Randall: Energy? Like bio, electric, solar, or what?
Senior Officer: No, Randall. Just. Pure. Energy.
Detective Randall: ...Odd.
Energy is formally defined as the capacity to do work (whilst work is defined as the energy transferred by a force).note Energy is not something you can, for example, pick up and put in your pocket.
But the famous "E=mc2" equation gave us a notion that matter and energy were interchangeable in a certain way, and, as they tend to, science fiction writers went off half-cocked with the idea.
You will therefore find the notion in quite a lot of Speculative Fiction that energy is just another form of matter, rather than simply a property of it— particularly, a sort of warm glowy kind of matter, whose exact properties can be fine tuned to user specifications, and which can be summoned or banished with a button-press.
In this sort of system, you can treat "Pure Energy" as a building material, and make things out of it. Such things would, quite naturally, be of higher quality than anything made out of mundane old matter. In the universe of real physics, claiming something is "made out of pure energy" is flat out nonsensical — it makes as much sense as saying you can make a car "out of pure velocity," or make pasta "out of pure yummy".
If we're feeling generous, we can suppose that they don't really mean to treat energy like a kind of matter, and are actually dealing with highly energized exotic matter, such as plasma, certain created energy sources or Phlogisticated Aether, but they really shouldn't be going around calling it "Pure Energy".
In Elemental RockPaperScissors settings, this enables "energy elements" — Fire, Lightning, Light, and Darkness — to be treated and manipulated the same as "material elements" — Air, Water, Earth, Metal, Wood.
Misinterpreting the law of conservation of energy — "energy cannot be created or destroyed" — to mean that objects made of "Pure Energy" are indestructible is a common subtrope. Of course, if "energy cannot be created", then we're left to wonder how, according to this subtrope, "Pure Energy" came into being in the first place. Or why the same rule doesn't apply to stuff made of Pure Matter (as the actual LoC does). note
- Energy Ball: An orb of the stuff usually used offensively.
- Energy Beings are people made of Pure Energy.
- Ball of Light Transformation, transforming to Pure Energy.
- A Swirly Energy Thingy is a Pure Energy-based Cool Gate.
- Laser Blades are swords forged out of the stuff.
- Sword Beams are beams that shoot out from swords.
- Deflector Shields are usually walls made of Pure Energy.
- Hard Light, when it's just "we turned up the power so high that it became solid" as in Automan, is a solid projection made of Pure Energy.note
- Frickin' Laser Beams are, by and large, simply conventional pistols that fire (slow) bullets made of Pure Energy, rather than being lasers or something similarly hard to dodge.
- Objects made by a Green Lantern Power Ring.
- Power Source to most advanced or magical machinery.
- Frequently a source of Non-Elemental damage.
- A Matter Replicator makes things out of energy.
- One of the brands of Leggs® panty hose was called "Sheer Energy".
- Smax in comic Top 10 can fire energy from his chest. This is later named "The Strong Light".
- A pure energy entity also appears in a Justice League comic from the late eighties. It's handled more realistically than most and a lot is made of the fact that it shouldn't exist. Captain Atom states that "According to what I remember about physics, any uncontained energy should dissipate immediately." and calls in Doctor Fate to make sure there are no supernatural explanations for a physics-defying... thing appearing out of thin air.
- Cyclops releases blasts of "pure concussive force" from his eyes.
- In the W.I.T.C.H. comic Will's element is defined as "Pure Energy" while the rest of the Guardians are a Four-Element Ensemble. In the TV series her element is defined as "Quintessence" which is basically Shock and Awe mixed with Lightning Can Do Anything.
- The Power Cosmic used by a number of Heralds of Galactus (some Heralds like Terrax or Nova and Firelord treat their Power Cosmic more like elementals) and Eternals (including Thanos) treat it as a mysterious energy that can be focused to a more specific more of energy like hard radiation, electricity and etc. The Power Cosmic can also be used to transmute matter.
- In The Avengers (2012), JARVIS says that the barrier around the Tesseract portal generator is made out of pure energy and cannot be destroyed (after Iron Man shoots it and gets hit with the reflected beam).
- In the TRON films and Expanded Universe, the sentient AIs drink the stuff for nourishment. Digitized humans can also benefit from drinking it.
- Notably Averted with the Star Wars "lightsaber". It's never really addressed on-screen, but various materials reveal that the blade is made from plasma (which is also probably Artistic License Physics, but in a different way).
- In the Alterien series, the Alteriens and the Enhanced can temporarily achieve a higher state in which their bodies are composed of pure energy. This is their most powerful form, but it only lasts for about 2 minutes.
- In the fantasy series, Astral Dawn, the high spirits are composed of pure energy and thought. However, the energy the high spirits and the astral plane are made of is of a higher dimension that conforms to different laws of physics. Simon explained it to Caspian as astral physics or dream physics.
- In the Discworld book Sourcery, a tower is built out of pure magic.
- In Gone, Sam can shoot energy beams from his hands.
- One episode of Blake's 7 features a force wall whose optical properties had been set such that it was indistinguishable from a normal door.
- Star Trek, the original series at least, might as well be the trope namer. The number of times Spock says "Pure Energy" over the course of the series is only rivaled by the number of times he says "Near Earth parallel, captain."
- Dungeons & Dragons:
- Magic missile spells are made of force, which is basically the same thing as "pure energy". Other force effects include the Bigby's line of spells, and a dragon that breathes force energy. It is explicitly noted that force is inherently magical and does not correspond to any non-magical natural phenomenon.
- Weapons with the "brilliant energy" enchantment have their blades or points transformed into pure energy that passes through inanimate objects to damage living things. The good news is that this ignores armor, the bad news is that this makes the enchanted weapons useless against the undead or golems.
- The Prime arcanum in Mage: The Awakening provides several varieties: pure Mana condensed to solid form for easy storage, Non-Elemental Celestial Fire, weapons and armour (and tables and stuff) created from Hard Light, and sentient constructs Made of Magic.
- Warp Energy in Warhammer and Warhammer 40,000. Technically it's psychic energy, composed of the thoughts and emotions of every sapient being, but in practice it is treated as this trope.
- Mega Man Star Force 2 featured Matter Waves. The futuristic society in the series essentially does just about everything using energy waves, such as creating snow for a ski resort, making fountains, and controlling... the... weather. Ignoring all of the completely ridiculous things done with it, however, you still have the Matter Waves, which are basically electromagnetic waves in tangible form. You have Matter Wave Skis, Matter Wave Vacuum Cleaners, Matter Wave MacGuffins, and Matter Wave BUTLERS.
- Despite his true form being a sentient computer virus, Sigma from the Mega Man X series is able to manifest a physical body in the real world while still in his viral form.
- Similarly, Cyber-Elves from the Mega Man Zero series are sentient computer programs given physical form out of energy, and can be upgraded using Energy Crystals.
- Lost Planet has "Thermal Energy", which is harvested by killing Akrid. It's some kind of glowing orange goo that has a large potency. Possibly overlaps with Green Rocks.
- Half-Life 2's Combine Dark Energy Orbs are balls of energy either kept in a stasis and used to power generators, or contained in a capsule which can be used as a weapon, releasing the orb which instantly disintegrates most biological lifeforms it comes in contact with.
- Final Fantasy VI has the boss Atma/Ultima Weapon, which before the battle boasts of being "pure energy, and ancient as the cosmos." It is no pushover. This trope is why beating it by draining all of its MP makes sense; without MP to sustain it, it can't exist. Until it comes back, of course.
- In Might and Magic VI, gold dragons and energy drakes hand out "energy" damage as distinct from fire, cold or electric, and so do "Ancient Weapons".
- In Albion, forcefields found in one dungeon are apparently made of pure energy. Considering that one of the heroes is a scientist, this understandably confuses him. He does manage to conclude that the field appears to be made of electrical discharges, but has no visible power source. He later concludes that information, energy and matter are interchangeable on the eponymous planet, allowing magic to exist.
- In X-COM: Enemy Unknown, the Outsider alien is deemed a being "made of almost pure energy" by Dr. Vahlen. She's just as confused as the rest of us, perhaps lampshading the impossibility of this trope.
- Nothingness gets this treatment in Kingdom Hearts II. In the Kingdom Hearts universe, Nothingness is a form of matter separate from Light and Dark, and inimical to both. It's the substance that the Nobodies are made of, though it also manifests as thorny, vine-like wisps that encircle the elemental attacks of Organization XIII's members (though Xemnas and the Twilight Thorn can use the wisps themselves as an attack). For a straighter example, there's Xemnas's and the Mysterious Figure's/ Young Master Xehanort's Ethereal Blades.
- Phantasy Star Online seems to be a fan of this, given that the game features futuristic energy weapons that are seemingly limitless in use. What plays this trope straight are the rare collectibles called 'Photon Drops' and 'Photon Spheres', which are described as a "High purity crystal Photon" and "Rare super pure crystal Photon', respectively. Photons are what the aforementioned energy weapons and guns are described to put out. Why bits of crystalized energy are so important to a side character is unknown, especially since the standard usable photon weapons have an unlimited amount of energy to function- but he'll be willing to offer extremely rare items and upgrade your equipment for them.
- To make things even weirder, the Photon Spheres and Photon Drops are depicted as any other rare drop when on the ground- a deep-red box probably only slightly larger than someone's head. Even if the model size isn't indicative of the item itself, one has to wonder how somebody is supposed to handle a crystalized form of a substance that is regularly shot out of guns and ejected out of blade handles for the purpose of shredding beasts and frenzied robots alike. Ouch.
- In Axiom Verge, one hidden weapon fires beams of "pure inertia."
- Spider-Man 2 Enter: Electro's final boss is "Hyper Electro" which, as described by Stan Lee in his in-game narration, is Electro "transformed into a being of pure energy". They probably meant to say "pure electricity" although that hardly makes any more sense.
- Sonic the Hedgehog: The energy provided by the Chaos Emeralds, sometimes called Chaos Energy. It can be used to shoot energy blasts, teleport, manipulate time, power electronic devices, and enter Super Mode, among other things.
- The Lazer Collection: Just. Pure. Energy. This disjointed collection of 4chan-esque shorts might be the only instance where the words "pure energy" actually make sense. The "lazers" are just a large wave of light, heat, and concussive force — the purest expressions of energy in a system — expelled all at once.
- Gene Catlow has seen a lot of this after Friendship Island was introduced.
- In The Inexplicable Adventures of Bob, the alien Nemesites claim that just as matter is a form of energy, there are other forms that humans haven't discovered yet, and their Sufficiently Advanced tech can create objects out of it that have weird physical properties.
- In Savage Divinity Heavenly Energy works this way, when harnessed it can be used to create matter and has all sorts of other seemingly impossible uses that defy common sense.
- In The Transformers, Energon, so near as we can tell, is Pure Energy which has been poured into a box for easy storage.
- The late G1 episode, "Call of the Primitives", featured a monster named Tornedron who was described as being made of "pure energy", thereby allowing him to assume many (apparently solid) forms and making him superior to Unicron, a being of matter... riiiight.
- Other incarnations, like Beast Wars, made Energon into a form of Green Rocks that generate a lot of power and have all sorts of funky effects.
- G1 Energon is weird. Any source of fuel can be poured into a cube made of... white outlines... and once inside, it promptly turns into glowy stuff that robots can drink or use to fuel stuff. All the other series (including Beast Wars, which actually follows G1) treat it as a natural resource that can be mined. It still blows up if you rub it the wrong way, though. Interestingly, most if not all weapons made of Pure Energy in Transformers are called "energon weapons". They seem to be quite solid. In Transformers Animated, the shiny parts of a weapon that's mostly made of shiny can hold the solid parts in place. It's... pretty safe to say that it all runs on Rule of Cool.
- At one point, Megatron concocts a scheme to convert tidal power into Energon, so apparently it's possible to fill Energon cubes by generating electricity. Also yes, he does this in a hilariously stereotypically evil way (by nearly crashing Cybertron into the Earth so the tidal forces at play would generate more waves).
- Dexter of Dexter's Laboratory once tried to produce pure energy in his laboratory. In the few moments before his machine crashed, it was depicted as a giant glowing atom (you get a better view of it in his grandfather's Rube Goldberg machine).
- Megabyte in ReBoot once extracted all the energy in Mainframe's core and converted it into a liquid state which was stored in a "transformer". But since this pure energy was unnatural it caused problems when the User loaded a game, including forcing the game to land on the Principal office, corrupting the game and turning Megabyte into a Megatruck.