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Dark Jedi is the name given in the Star Wars universe to fictional characters attuned to the Force and adept in its dark side. They exist by that name only in the Expanded Universe, including video games such as Star Wars: Knights of the Old Republic and the Jedi Knight series; the term is never used in any of the six Star Wars films. By Episode I, Lucas had established the specific term for the "Dark Jedi" as Sith.

Dark Jedi is a label to a specific archetype of characters in the Star Wars Expanded Universe defined as Force-attuned beings that meet two requirements: They do not hold themselves to the dogma of either the Jedi or the Sith, and they use their Force abilities for less than virtuous acts that would normally be looked down upon by the Jedi Order. As it has been mentioned, the concept of Dark Jedi is not endorsed anywhere within either movie trilogy. Dark Jedi in the Expanded Universe typically refer to students of Luke Skywalker's Jedi Academy who have fallen to the dark side. Dark Jedi are also extremely common in the Knights of the Old Republic series in league with the Sith Empire and are often fallen Jedi from the Mandalorian Wars. Dark Jedi also appear in the Jedi Knight series of Star Wars video games, where Kyle Katarn uncovers Imperial plots linked to Dark Jedi. In Jedi Outcast, Katarn faces an entire army of Dark Jedi, cloned and lightly trained force users who follow the main antagonist. Dark Jedi have distanced from Sith in more modern Star Wars media. They are not sworn enemies of the Jedi Order and do not consider destroying it a priority as Sith do. Dark Jedi do not always appear in pairs with a master and apprentice and often work alone.

Because the term Sith was never spoken in the original trilogy (although Darth Vader was described as "Lord of the Sith" in the published screenplay), early Expanded Universe products usually considered the "evil Jedi," those who joined the dark side of the Force, as "Dark Jedi." In his novel series The Thrawn Trilogy, author Timothy Zahn labeled Sith Lord Darth Vader and Emperor Palpatine as Dark Jedi, and the term "Sith" was never mentioned in the series until later reprints of the novels.

Dark Jedi use the Force for their own ends while attempting to utilize both sides of the Force, owing no allegiance. They do not exclusively bond themselves to either the light or dark sides of the Force. While a Dark Jedi can use Jedi and Sith Force arts with ease, they rarely obtain the mastery of either side. Palpatine trained many Force-sensitive beings in the ways of the dark side of the Force, but most were never initiated into the rites and secrets of the Sith. Force-sensitive individuals seem to arise spontaneously and may become adept at the Force without Jedi or Sith involvement. It is true, however, that many notable Dark Jedi have received at least some Jedi training.

Dark Jedi has not been a contender in any CBUB matches.