- "You have done well, my apprentice...for now."
- ―Darth Sidious
A Sith Apprentice was an initiate into the ranks of the Sith Order. Typically some moppet who had a smattering of Force training and had wandered in after proving to be too much of an emo for the Jedi Order to train, they were seldom given any respect. They were essentially the red-headed stepchildren of the Dark Side, and had to prove themselves worthy to become a Sith Lord by engaging in often ridiculous tests of power and/or other Sithy talents and trades. If the person in question passed their tests and lived to tell the tale, they were promoted to Sith Lord.
If an apprentice had not proved worthy by a certain age, but had also not displeased their teacher so much as to be killed just for being an annoying twat, they were given the title of Sith Underlord and generally relegated to doing menial labor, such as destroying minor moons or knocking space stations out of orbit.
In actual practice, apprentice was more a state of being than a formal rank. Apprentices were those who wanted to be Sith, but didn't yet have the gumption, those who were just beginning their journey down the dark path, or those who had bonded themselves to a powerful Dark Lord for some reason or other.