The game takes place 4,000 years before the rise of the Galactic Empire. Darth Malak, a Dark Lord of the Sith and Darth Revan's former apprentice, has unleashed a Sith armada against the Republic.
Malak's aggression has left the Jedi scattered and vulnerable; many Jedi Knights died in battle and others swore allegiance to Malak. The game opens with the player's character, whom the player can choose a face and be either male or female awakening aboard a Republic ship under attack by Malak's forces.
After escaping the ship and landing on Taris, the player's character gradually gathers companions and pieces together his or her past while attempting to stop Malak's forces. While taking refuge at the Jedi Academy on Dantooine, The character learns to be a Jedi and the group discovers a "Star Map" and learns of the "Star Forge"–the probable source of Malak's military resources. But the Star Map is ancient and its files corrupted–the group can only access a portion of the map's memory.
The Star Map mentions other planets across the galaxy - Dantooine ,Manaan, Tatooine, Kashyyyk and Korriban, and the group surmises there might be similar Star Maps on those planets that will help them piece together more information about the Star Forge. In searching for these maps, the main character's actions and speech influence whether he aligns with the light or dark side of the Force.