Universe Overview

Mass effect as a term refers to a phenomenon utilizing a special element that is the key to much of the technology of the Mass Effect universe.

Element Zero (atomic number 0, atomic symbol Ez), colloquially referred to as eezo, is the key to everything. The basic idea is this: it is an element with zero mass that, when subjected to an electrical current, produces a 'mass effect' field. A positive current increases mass and a negative current decreases mass of all objects within the field. Mass effect fields can be used to create homogeneous alloys or super dense construction materials, artificial gravity, faster than light travel, practical and hand held mass driver weapons, and countless other applications.

The Mass Effect universe is divided into two rough partitions; citadel space and terminus systems. Citadel space is dominated by the Citadel council, and the races involved in this pact abide by the citadel's laws and cooperate with it's administration. The Terminus systems exist outside of the Citadel's jurisdiction and comprise of multiple governments and unofficial self-governed bodies that generally do not get along with each other very well. This lack of cooperation is what keeps the Terminus systems from going to open war with the Citadel.