Rank 3: Star Forge
The Star Forge is a very special superweapon because it primarily does not self-destruct. It comes from the Rakata, a people that also developed other innovations such as prototypes of hyperspace drives. They created the Star Forge around 30,000 years before Episode 4. It is an artifact that resembles a space station (you can see an image in the Wookiepedia).
The special thing about it: The Star Forge manufactures items – as the name suggests. It uses the dark side of the Force and the energy from nearby stars. Therefore, anything that the owner of the Star Forge desires can be created. This includes troops, spaceships, entire fleets, and armies. There is no limit; the Star Forge is practically an infinite source, which can be devastating if evil beings use it.
The Rakata themselves perished from this power, using the Star Forge in terrible ways and causing the death of billions of beings. The weapon first appears in the game Knights of the Old Republic, where the great battle occurs in which Revan fights against Darth Malak.
