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Elerium in the periodic table of elements.

Elerium, also known as element 115, is the primary energy source for alien technologies. It fuels alien ships and can be recovered from UFO landing and crash sites in XCOM: Enemy Unknown. Elerium also plays a role The Bureau: XCOM Declassified, but is not a player-collected resource.

In-Game DescriptionEdit

Gray MarketEdit

This element is unlike anything ever discovered throughout decades of research and space exploration. As of yet, we have no means of artificially recreating this material, so we should manage our limited supply accordingly.

Gray Market description

Research ReportEdit

It's clear this element is unlike anything found on Earth. The unusual atomic structure of this substance responds to direct bombardment from accelerated particles, resulting in an astonishing release of energy. [...] The potential applications for this element are nearly unlimited. [...] It has the potential to change the entire economic structure of Earth's energy industry. If we were to discover the source of this material, our reliance on fossil fuels could disappear within a decade.

Dr. Vahlen, research report extract


Elerium is acquired by successfully completing missions involving all classes of alien ships. A Small Scout can yield up to about thirty units of element 115, while Battleships and Supply Barges can yield well over a hundred. Quantities are closely related to the number of UFO Power Sources aboard a ship. On Easy difficulty 30 units of Elerium can be recovered per power source. This is decreased to 25 on all other difficulties. When a ship is intercepted and crashes, a minimum of 25% and maximum of 50% of its Elerium is lost. [1]

Gray Market ValueEdit



Elerium is used for projects that have substantial energy requirements. It can generate power for XCOM headquarters, and is required for the manufacture of advanced body armor, weapons, and interceptor armaments. Element 115 is also consumed during a variety of equipment upgrades and research projects.

Selling Elerium may not be advisable as it soon becomes a staple resource. It is used for a total of fifty projects (including those added in XCOM: Enemy Within), second only to Alien Alloys in the number of potential applications.

Click the tabs (above) for complete lists of XCOM projects that require Elerium.

XCOM Facilities
Elerium Generator30 Psionic Labs20 

Quantities listed are base values. Actual Elerium consumption may vary.
EW indicates a project added by XCOM: Enemy Within.


  • The Second Wave option "E-115" (unlocked by beating the game on Impossible difficulty) gives Elerium a half-life of 15 days, resulting in the loss of 4.52% of XCOM's stock per day.


  • Instances where Elerium is referred to as "Elerium-115" rather than "Elerium 115" are an oversight. The hyphen incorrectly indicates an atomic mass instead of the atomic number.
  • In the original UFO: Enemy Unknown (1994) Elerium samples are purple, and it as been portrayed in a variety of colors since.
  • In 1997's XCOM: Apocalypse, which takes place after the events of Enemy Unknown, Elerium has become the de facto power source for human interplanetary travel and military weaponry. It is mined from distant planets and transported to Earth.
  • The use of element 115 as an alien power source is a reoccurring concept in modern science fiction. It originates from a 1980s claim that the element is used as fuel for a "gravity wave generator" that propels UFOs studied near Area 51.
  • Element 115 was synthesized and observed for the first time in a 2003 atomic laboratory experiment. Temporarily named "ununpentium" and finally "moscovium", it is highly unstable and has a half-life of 200 milliseconds.
  • Refined Elerium is exceedingly volatile and apparently hazardous if handled without proper protection, as mentioned by Agent John Kinney when William Carter asked why couldn't they bring the element with them if its so valuable.



  1. DefaultGameCore.ini. Game File. XCOM: Enemy Within (2013).
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