Savage Mass Effect
The Mass Effect, Element Zero and the Mass Relays
When subjected to an electrical current, the rare material dubbed element zero, or "eezo", emits a dark energy field that raises or lowers the 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 orbit 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.
In space, low-mass fields allow FTL travel and inexpensive surface-to-orbit transit. High-mass fields create artificial gravity and push space debris away from vessels. In manufacturing low-mass fields permit the creation of evenly-blended alloys, while high mass compaction creates dense, sturdy construction materials.
The military makes extensive use of mobility enhancing technologies, with mass effect utilizing fighting vehicles standard front-line issue in most military forces. Mass effect fields are also essential in the creation of kinetic barriers or shields to protect against enemy fire.
Mass relays are feats of Prothean engineering advanced far beyond the technology of any living species. They are enormous structures scattered throughout the stars, and can create corridors of virtually mass-free space allowing instantaneous transit between locations separated by years or even centuries of travel using conventional FTL drives.
Primary mass relays can propel ships thousands of light years, often from one spiral arm of the galaxy to another. However, they have fixed one-to-one connections: a primary relay connects to one other primary relay, and nowhere else. Secondary relays can only propel ships a few hundred light years, however they are omnidirectional: a secondary relay can send a ship to any other relay within its limited range.
There are many dormant primary relays whose corresponding twins have not yet been located. These are left inactive until their partner is charted, as established civilizations are unwilling to blindly open a passage that might connect them to a hostile species.