Elerium 115: The Alien Fuel X-COM Makes You Take From the Enemy
Your scientists have cracked the aliens' technology, your engineers are ready to build it, and the whole plan stalls on a shortage of one thing: Elerium 115.
That's the original X-COM in a nutshell: the enemy controls the supply of your best fuel.
The name is no accident, either. A real element 115 exists, and a Las Vegas man named Bob Lazar had been calling it flying-saucer fuel for five years before the game came out.
The game's designer has even said where the idea came from.
We'll get to that. First, what does the stuff actually do?
What Is Elerium 115?
Elerium 115 is the fictional energy source in X-COM: UFO Defense, the 1994 strategy classic also released as UFO: Enemy Unknown. It was designed and programmed by Mythos Games, the studio of brothers Julian and Nick Gollop, and published by MicroProse.
Inside the game, an encyclopedia called the UFOpaedia explains each alien wonder you recover. The community-run UFOpaedia wiki preserves the Elerium entry word for word.
"This element has the unusual property of generating anti-matter power when bombarded by certain particles. This creates gravity waves and other forms of energy."
The entry goes on: "It is not naturally found in our solar system and cannot be reproduced."
In play, that translates into two jobs. Elerium fuels your best craft, the Firestorm, the Lightning and the Avenger, and it's an ingredient in most of the alien gear you manufacture, including the Flying Suit.
Knowing how it works is only the start of putting it to use. You need a supply, and the aliens are the only source.
Why Can't You Just Make More?
The rules are strict: Elerium cannot be synthesized on Earth. Once your researchers understand it, you still can't manufacture a single unit.
The only way to get it is to take it. Elerium sits inside the power sources of UFOs and alien bases, so every successful assault sends whatever survived back to your stores.
That word, survived, matters. The power sources are fragile, and if a UFO's power source was wrecked in the crash, its Elerium went with it.
So the game quietly rewards restraint. A UFO caught on the ground, or a supply ship ambushed near an alien base, tends to hand over more fuel than one blasted out of the sky; the wiki rates an intact supply ship at 150 units.
You can sell it for $5,000 a unit. The wiki's advice on that is one word: don't.
That's the loop the whole game is built on. The official game description puts you "in control of X-COM: an organization formed by the world's governments to fight the ever-increasing alien menace," and the fight runs on what you bring home.
The original player's handbook spells out the cycle: "Successful ground assault missions mean that X-COM scientists can research alien technology. Engineers can then reproduce their superior weapons and spacecraft."
Elerium is the twist in that cycle. Just when a discovery makes you feel unstoppable, it gives you another reason to head back into the field.
Where did a strategy designer get the idea of an alien element with a number attached? As it happens, he's told us.
Where Did the Idea Come From?
Julian Gollop laid out the game's origins in a 2011 NowGamer interview. The project began as a sequel to his tactical game Laser Squad, until MicroProse's head of development, Pete Moreland, asked for something "bigger" and suggested UFOs.
Gollop did his homework. He bought a tape of the old Gerry Anderson TV series UFO, which gave him the idea of a worldwide organization set up to stop an alien menace.
Then came the book that matters here. Bob Lazar is the Las Vegas man who told reporter George Knapp in 1989 that he'd helped reverse-engineer recovered flying saucers at S-4, a hidden site near Area 51, and our Bob Lazar and Area 51 story has the full account.
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"The other thing that was influential was a book by Bob Lazar," Gollop said, "where he describes his experience of working on recovered UFOs in Area 51, and how the US government were allegedly trying to reverse-engineer captured flying saucer technology."
That, he added, "was a major influence on the whole cycle of shooting down UFOs, investigating crash sites and capturing alien technology in X-COM."
In that interview, Gollop didn't mention Elerium itself. But the number Lazar attached to his saucer fuel, 115, is the number on the game's miracle element, and the loop he inspired is the loop Elerium keeps turning.
Which raises the obvious question: is there really an element 115? There is, and it has a name.
Is There a Real Element 115?
Its name is moscovium, symbol Mc. An atomic number counts the protons in a nucleus, so "element 115" simply means an element whose nuclei hold 115 protons.
Scientists could talk about that combination long before they made it. The periodic table's numbering already told them what the target would be, which is how Lazar could name it in 1989.
The first atoms arrived in 2003, when a Russian–American team in Dubna, in the Moscow region, fused calcium and americium nuclei and caught four atoms of element 115. Our real element 115 guide follows the whole discovery, right up to the name it received in 2016.
- Put recognizable images beside the names and symbols of chemical elements
- Make the periodic table easier to explore through a visual presentation
- Build a scientific reference point for reading about unusual materials and elements
So the number is real. Could the real thing refill an Avenger?
Would Moscovium Work as the Game's Fuel?
Not even close, and the reasons are fun. Real moscovium is made a few atoms at a time, and each one falls apart in a fraction of a second.
Nobody has ever had enough to weigh, let alone stockpile. The Los Alamos National Laboratory entry labels its melting point, boiling point and atomic radius as predicted, because there has never been a piece to measure.
Nor has it shown any hint of the antimatter trick. That property belongs to the game's UFOpaedia and to Lazar's story, not to any lab measurement.
If the names are blurring together, here's the quick guide:
| Name | Where It Belongs |
|---|---|
| Elerium 115 | The fictional fuel in X-COM. |
| Element 115 | The scientific label for any nucleus with 115 protons. |
| Moscovium, Mc | The real element's permanent name and symbol. |
| Ununpentium, Uup | Its former temporary name and symbol. |
They're easy to connect in conversation because of the number. The laboratory version won't refill your Avenger, though.
How much of the game's fuel came from Lazar's, then? More than the number.
How Close Is Elerium to Lazar's Element 115?
Put the two descriptions side by side and they rhyme:
- Antimatter: Lazar said bombarding 115 with protons released antimatter; the UFOpaedia says Elerium generates "anti-matter power when bombarded by certain particles."
- Gravity: Lazar's reactor produced a gravity wave the craft amplified; the game's entry says the reaction "creates gravity waves."
- Origin: Lazar said 115 could only form near a supernova or a binary star; Elerium "is not naturally found in our solar system."
- Supply: Lazar said synthesizing it "would be impossible"; Elerium "cannot be reproduced."
Both stories give an extraordinary material the job of explaining extraordinary machinery. Our Lazar and element 115 timeline follows his claim all the way to the discovery.
Gollop's interview settles where the inspiration came from, but not every detail. He credited Lazar's story with the cycle of recovery and research, and left the fuel unmentioned, so the rest of the resemblance is yours to judge.
The real search for an island of stability adds one more twist. Scientists really are hunting for versions of superheavy nuclei that last longer, though extra lifetime wouldn't bring the game's propulsion powers with it.
So why does a made-up mineral work so well in a game?
Why Is Elerium Such a Good Game Resource?
Because it does two jobs at once. It explains the alien machinery inside the fiction, and it hands the player a limit that research can't remove.
Even after you understand the technology, you still have to think about what it costs to use. A successful mission solves tomorrow's supply problem as well as today's fight.
The series knew it had something. The sequel Terror from the Deep swapped in an equivalent called Zrbite, and the 2012 game XCOM: Enemy Unknown brought Elerium back by name.
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Real moscovium belongs to the story of scientists catching atoms before they vanish. Elerium belongs to the far more urgent problem of getting your squad home with the power source intact.
Element 115: The Real Element Behind the Flying Saucer Fuel Story
Bob Lazar and Element 115: How Did He Know?