1.) Sith Apprentice
Requirements: Be picked by the Sith Lord to become a Dark Jedi.
2.) Sith Adept
Requirements: Pass the exams and learn four darkside force powers.
3.) Sith Lord
Requirements: Pass Sith Lord Exam, beat or kill your Master in a fight, learn ten darkside Force powers.
Dark Lord of the Sith
Requirements: Become the most powerful Sith Lord and take control of the Dark Jedi, either by force or fear.