Some of the softer Science Fiction has its new technology powered by something different from plain old electricity, nuclear power, phlebotinum, Functional Magic, or petrol. Depending on the series, this can be either for something Powered by a Forsaken Child, or a source that gives power to no (or little) ill effect.
Just to be clear, if the fuel source exists in Real Life, it isn't an example. Mysterious new substances and energy sources also don't count.
Compare Magitek, which is usually fueled this way.
Powered by a Forsaken Child examples:
- Zearth and the other robots in Bokurano require the life force of the pilot after being used. Because of this each team has 14-15 pilots to go through after the others die.
- In Fullmetal Alchemist, the Philosopher's Stones that allows alchemists to bypass the law of Equivalent Exchange are created from the souls of living humans. At one point, Ed uses his own soul to keep from dying. He gets better, though.
- In Kamen Rider Den-O, Kamen Rider Zeronos' Transformation Trinket runs on memories. Every time he transforms, more people forget ever meeting him. Which is bad enough on its own, but it also runs afoul of Den-O's Time Travel rules: if something happens to your past self and nobody remembers that you exist in the present, you don't.
- The Chancels of the Player Characters in Nobilis require the deaths of one hundred human beings (or equivalent sacrifice) to be created.
- In Warhammer 40,000, the Emperor's Golden Throne is powered by 1,000 powerful souls per day.
- And not just any soul. Only the best, most talented psychic souls will do. Fortunately, there's no lack of those for a species who number in the trillions.
- Lifejammers in the Spelljammer D&D setting worked like this (they worked basically like ordinary spelljammers, except draining life-force instead of spells to provide the motive force. Life-force does not replenish as easily as spells...).
- In Deadlands, all "new science" technology works on Ghost Rock, which is.... you guessed it right, dead people's souls.
- The Persona and Shadows of Persona 3 are powered and personify human emotions. Persona themselves are summoned by shooting a character in the head with a gun that fire pure psychological trauma.
- The Mako and Materia of Final Fantasy VII are fueled by the life force of the planet, with mako being especially unhealthy to deal with. Square and SquareEnix in general is a big fan of this. Final Fantasy VIII has Guardian Forces powered by consuming memories, most technology in Final Fantasy IX is ultimately powered by dead people's souls, and Espers are essentially magic through crystalized demihuman souls.
- In game, the explanation for the Guardian Forces is a bit different. They need room inside a person's head to be able to work with them. The neurons they take over happen to be the neurons that keep your memories. Probably more benign than if they'd take your visual cortex or primary motor cortex.
- In Tales of Symphonia exspheres are "grown" on human slaves, at the cost of turning them into big slimy monsters. Lloyd's exsphere contains the soul of his mother
- Breath of Fire IV has a particularly horrific example in the Carronade; aforementioned Carronade is literally a Fantastic Nuke powered by Metaphysical Fuel that is generated via the Cold-Blooded Torture (to the point of suicidal despair and insanity) of those who have close connections with the intended Ground Zero. (Yes, you're reading this right—it's a Fantastic Nuke that not only uses tortured Forsaken Children as its Metaphysical Fuel but explicitly operates on the theory that Love Hurts. In fact, the deeper the love, the deeper the metaphysical radiation poisonong goes.)
- Oh, and the one time where the use of the Carronade was depicted (rather than its aftereffects) was when the Evil Empire literally used the girlfriend of its King in the Mountain and God-Emperor as Metaphysical Fuel for the Carronade because she was his girlfriend and was in love with him (this merely got aforementioned God-Emperor royally pissed off and threw him over the Despair Event Horizon into Woobie, Destroyer of Worlds territory). The Comic-Book Adaptation in particular depicts the latter in especially tragic fashion.
- You build your equipment in Shin Megami Tensei: Strange Journey out of bits and pieces of demons. This can range from the relatively mundane ("Reaper Knife", "Tyrant Glacier") to the... unnerving ("Haunt Rib", "Dragon Eyeball").
- All magic in Don't Starve is powered by actual Nightmare Fuel. An update even introduced an ancient civilization that got destroyed by overusing Nightmare lights.
- Dr Thadius Venture of The Venture Bros. invented a booth that will let the user experience their most intimate fantasies as though reality. Nice guy necromancer Dr. Byron Orpheus discovered to his horror that the machine was powered by the soul of an orphan.
- The Tick TV series once featured a race of aliens whose ship ran on fear. Their own fear, given that they're the most timid and cowardly race in the galaxy. Second-most timid and cowardly, that is. They're topped by Arthur, who is by nature so anxious and skittish that when they hook him up as the ship's fuel source, the thing reaches speeds the aliens didn't even realize were possible with their system.
- The monster world in Monsters, Inc. is powered by children's screams. Turns out laughter works much better.
- Gunmen in Tengen Toppa Gurren Lagann are powered by Spiral Energy, which is generated by the pilots' fighting spirit. They can also be powered by more conventional means, since the Beastmen are an artificial race and cannot generate any Spiral energy. However, Spiral energy subverts the "little to no ill effect" part of the trope: since they're literally breaking the second law of thermodynamics by creating energy, using it too much will eventually result in the universe collapsing, an event termed the 'Spiral Nemesis' in-series.
- The titular flying vehicles in Simoun are powered by the souls of their pilots uniting in common goal and desire...which just so happens to expressed by the two pilots kissing.
- In Eureka Seven, Humongous Mecha fly on the thoughts of a giant alien being covering the entire planet.
- The G-Stone in GaoGaiGar is powered by courage!
- "Stealing GGG's will to fight! Turning me and Gao Figh Gar against them! Splitting us up across the world! It's all because you were afraid! Afraid that the G-Stone would transcend the power of the Loud G-Stone! This is the power born from courage!!"
- Compare and contrast: The Character Guardians from Shugo Chara! are powered by their owner's will to change their own personality, the exact opposite of a persona.
- The Lambda Drivers in Full Metal Panic! are powered by the anger of the Humongous Mecha pilot. Good for Determinators and Ax Crazies.
- The Green Lanterns and related corps are powered by the emotions of all living things. The GLC itself is fueled by Heroic Willpower; the others are Unstoppable Rage, Greed, Fear, Hope, Compassion, and The Power of Love. There is a danger for several corps that the emotion they wield will overpower them (for example, the Star Sapphires that use love energy are subject to Love Makes You Crazy).
- "Obsession" might be a better name for it than "Love". It's not just a coincidence that their entity is named Predator.
- The Hitchhiker's Guide to the Galaxy has several.
- The Heart of Gold is powered by improbability.
- The Bistromath is powered by the uncanny mathematics involved in splitting the bill in a restaurant.
- An alien race designed a ship powered by bad news, the one substance in the universe that can travel faster than light. But they never worked very well and no one wanted them around, so people stopped using them fairly quickly.
- The Intention Craft in His Dark Materials is powered by the user's intentions.
- Dwarven asteroid/ships in Spelljammer are made to move by the cumulative determination and work-ethic of their occupants, channeled through magic anvils.
- In Warhammer 40,000, the Orks' vehicles are partially powered by the Orks' belief in them. This leads to red vehicles flying faster simply because they can.
- The ANIMa of Bliss Stage are powered by Intimacy.
- Each of the main character's many Persona in Persona 3 are powered by and reinforced by the strength of related relationships he has.
- The Persona in Persona 4 are powered by the need of an individual to face life's hardships. They only have superpowers when battling enemies, but gaining a persona results in a dramatic change in the character's personality by the time their social link is maxed out ( Yosuke realizes his attempt at heroism was just running away from his guilt, Chie realizes she doesn't have to protect everyone and can also let herself be a girl on occasion, Yukiko at first decides she wants to leave Inaba to avoid the fate of inn manager, but eventually realizes that's what she wants to do, Kanji realizes that it's okay to like supposedly-girl stuff and it doesn't make him gay, and so on....
- The psychic powers each Player has in The World Ends with You are powered by imagination, and those who survive the Game are often recognized as geniuses by other people. The game's resident Mad Mathematician is an incredibly powerful boss, and he is stated to have huge amounts of imagination. Neku was chosen as the Composer's pawn specifically because he had an extremely good imagination: there is literally no pin he cannot use, compared to most other players who can only use one.
- Space Channel 5 has giant lasers and floating platforms powered by "dance energy".
- In an episode of The Simpsons, Ed Begley Jr. designed a go-kart powered by his own sense of self-satisfaction. It worked very well.
- My Little Pony: Friendship is Magic has the Elements of Harmony which are powered by virtues (Honesty, Kindess, Generousity, Laughter, Loyalty and Magic) and by The Power of Friendship.
- It's implied that Sidhe magic in Barry Blair's comic Elflord is powered by Yaoi.