Reaver Movement

Reavers are a cult of humans dedicated to the worship of technology. Unlike the Brotherhood of Steel, Reavers feel technology has an important religious signifigance. While Reavers revere technological instruments and weapons, they were not allied with the Calculator's robots, and were in fact attacked by them. The Brotherhood of Steel rescued them, in exchange for their newly developed EMP (Electro Magnetic Pulse) weapons and technology. The sole reason the Brotherhood rescued the Reavers was because they wanted EMP weapons to help defeat the Calculator's robots.

Appearances in games
Reavers appear only in Fallout Tactics, where they're opponents, and later allies of the Brotherhood of Steel.