Element Zero ("Eezo")

Mass Effect, Mass Effect 2 & Mass Effect 3
When subjected to an electrical current, the rare material dubbed element zero, or "eezo," emits a dark energy field that raises or lowers mass of all objects within it. This "mass effect" is used in countless ways, from generating artificial gravity to manufacturing high-strength construction materials. It is most prominently used to enable faster-than-light space travel.

Eezo is generated when solid matter, such as a planet, is affected by the energy of a star going supernova. The material is common in the asteroid debris that orbits neutron stars and pulsars. These are dangerous places to mine, requiring extensive use of robotics, telepresence, and shielding to survive the incredible radiation from the dead star. Only a few major corporations can afford the set-up costs required to work these primary sources.

Humanity discovered refined element zero at the Prothean research station on Mars, allowing them to create mass effect fields and develop FTL travel.

Mass Effect: Andromeda
Also known as "eezo," the rare material known as element zero generates a field when subjected to an electrical current, which raises or lowers the mass of all objects within it. This "mass effect" forms the basis of modern technology, from weapons and manufacturing, to enabling faster-than-light travel.

Element zero is generated when solid matter, such as a planet, is affected by the energy of a star going supernova. The material is common in the asteroid debris that orbits neutron stars and pulsars, though mining such regions is extremely hazardous and requires significant investment.

Surveys of the Heleus Cluster suggested the region is rich in element zero, which was a deciding factor in the Andromeda Initiative's decision to settle there. Without eezo, the Initiative's technology would quickly become obsolete.