The first title, and subsequent massively multiplayer online role-playing game series, was developed by BioWare while the second was done by Obsidian Entertainment per LucasArts' request.

[2][3][4] The series includes "Gray Jedi" who tend to follow their own path as far as the Force is concerned rather than obeying the light or dark side.

The game opens with the player's character awakening aboard a doomed Republic capital ship with no recollection of their past.

After escaping the ship and crash-landing on Taris, the player gradually gathers companions and pieces together their past while attempting to stop Malak's forces.

During the Mandalorian Wars, the Exile served under Revan who ordered the activation of a devastating gravitational superweapon – the Mass Shadow Generator – that caused so many deaths to the point where they stripped themself of all connections to the Force unconsciously to save themself, and was removed from the Jedi Order.

In the end, if the character is light-aligned, the Mass Shadow Generator is activated and destroys Malachor V and the Exile goes into unknown space to find Revan.

These include, for example, Dantooine and Korriban, the locations for the Jedi Academy and the Sith Academy, respectively; aboard the Star Forge space station where the final battle between master and apprentice takes place in KotOR; and war-ravaged Telos and its orbiting Citadel Station.

In The Old Republic, players have access to even more planets, like Ord Mantell, Nal Hutta, Balmorra, Alderaan, Tatooine, Dromund Kaas, Taris, Belsavis, Voss, Hoth, Corellia, Ilum and Quesh, and the moon Nar Shaddaa.

Per request as to have time to deal with other matters, BioWare, the original developer, handed over the job to Obsidian Entertainment.

[1] In addition to technical changes – such as more combat animation and interface scaling – The Sith Lords includes several drastic changes from the original game's features.

[19] Upon its cancellation, the Proteus project's team and elements of its designs were applied to developing Star Wars: Knights of the Old Republic 3.

[21] Concept art from the cancelled Knights of the Old Republic 3 project was published in the book Rogue Leaders: The Story of LucasArts (2008); the artwork includes depictions of Taloraan, Rodia, and a Mandalorian city, as well as a Coruscant vehicle and a new character named Naresha.

[23][24][25] On the remake's development, lead producer Ryan Treadwell wrote: "We’re rebuilding it from the ground up with the latest tech to match the groundbreaking standard of innovation established by the original, all while staying true to its revered story".

[23] Several individuals who worked on the original game are returning for the remake, such as former BioWare developers and Jennifer Hale (reprising her role of Bastila).

[34] Select characters from the series have also made a non-canon appearance in the mobile turn-based role-playing game Star Wars: Galaxy of Heroes, released on iOS and Android in November 2015, also published by Electronic Arts.

[35] The second comic series, titled Star Wars: Knights of the Old Republic, takes places around 3964 BBY, approximately eight years prior to the story of the video game series, and focuses on Zayne Carrick, a Padawan framed for the murder of his fellow Padawans by his masters, who are members of a mysterious Jedi Covenant.

An webcomic series, titled Star Wars: The Old Republic: Threat of Peace, was written by game developer Robert Chestney with art by Alex Sanchez.

A second webcomic series, titled The Old Republic: Blood of the Empire, was written by Alexander Freed, with art by David Ross, and follows the story of a Sith apprentice on a dangerous secret mission set 25 years before the Treaty of Coruscant.

A third series by Alexander Freed and David Ross, titled Star Wars: The Old Republic: The Lost Suns, was released, in printed form, monthly from June 8 to October 12, 2011, by Dark Horse.

Written by Paul S. Kemp, it tells of Darth Malgus, the Sith Lord responsible for the sacking of Coruscant.

Another novel written by Sean Williams called Star Wars: The Old Republic: Fatal Alliance was published on July 21, 2010.

In April 2019, Kathleen Kennedy was asked by MTV News about a potential Knights of the Old Republic adaptation and stated, "Yes, we are developing something to look at.

[36] The following month, BuzzFeed News reported that Laeta Kalogridis had been hired in the spring of 2018 to write a film based on the 2003 video game, and that she was close to completing the first script of a potential trilogy.

Based on 30 professional reviews, Metacritic gave the game an average rating of 85 out of 100,[41] compared 93 for Knights of the Old Republic.

[45] G4TV gave a review of 5/5 and praised the game for "Top notch music and voice acting" and "hundreds of hours of content.

[47] Gamespy gave a review of 4/5, praising the story lines and companion system but criticising the "standard kill and fetch" quests.

"[49] GamesRadar gave the game 8/10 calling it "an extremely satisfying experience that sets the stage for a bright future".