Unlike the Jedi, who have an entire order made up of thousands of representatives, the Sith operate under what is called The Rule of Two. Established in Star Wars Episode I: The Phantom Menace, when Yoda says, “Always two there are. A master and an apprentice.” In canon, this idea is laid out by Darth Bane after the large number of Sith turned on each other, allowing the Jedi to defeat them. Bane laid down the Rule of Two to allow the Sith to operate in secret without the Jedi being able to detect them if they were in large numbers; a solid idea in theory, but one that raised some questions for many fans.
How were the Sith ever able to accomplish their goal, given a built-in rule designed to encourage replacement and usurpation? Is it smart to train one’s own replacement? Can they ever work together? Well, the latest novel, Master of Evil by Adam Christopher, explains exactly how the rule works. Set shortly after the events of Revenge of the Sith, the story explores Vader’s quest to conquer death itself, his original motivation for joining the Dark Side to save Padme. In his journey, he uncovers the secrets of the Sith’s Rule of Two and how a Sith Master keeps an apprentice around to grow their own power, not pass it on.
A Sith Master Needs the Apprentice To Be Powerful
The Sith Rule of Two creates a dichotomy between the master, who embodies the power of the dark side, and the apprentice, who craves that power. Master of Evil expands on this idea, offering greater insight into exactly how the Sith Master-Apprentice relationship works, as an inverse of the Jedi relationship between master and apprentice. The book states:
“The power of the dark side is the truth, but it is not a truth to be shared. Its secrets are to be gathered, hoarded, kept for the self. That is how it is meant to be. The master’s strength and power come from the anger and fear of his apprentice. The master uses that power, absorbing the resentment, fueling the fire, focusing his power and his grip on the dark side. It is the apprentice that makes the master, not the master the apprentice.”
This means that the Sith Master feeds on their apprentice, whereas a Jedi trains their apprentice to surpass them. A Sith Master keeps his apprentice always grasping for power, making them more resentful of being an apprentice, which in turn makes the Master more powerful. They never intended to pass on their knowledge, with it either ending in the apprentice being destroyed and the master needing to find a replacement, or the apprentice somehow usurping their master. How can an apprentice accomplish this if the master draws power from them?
This often leads the apprentice to begin training an apprentice of their own in secret, as they can unite to overthrow a master, as Count Dooku attempted to do with Asajj Ventress before Palpatine ordered her killed. When Darth Maul broke free from Palpatine, he became even more powerful, not only because of his knowledge and experience but because he took on an apprentice of his own, Savage Oppress. This creates a system of resentment and anger that passes on.
The Acolyte hinted at this idea as well, with Qimir possibly being the original apprentice of Darth Plageuis the Wise. Qimir’s intent might have been to overthrow his master when he takes on his own apprentice, Mae. Qimir and Mae’s fate remains unknown (though it is heavily implied that Qimir would be the first Knight of Ren), but eventually Plageuis would adopt Sheev Palpatine as his apprentice, who, in order to become the master, later kills Plageuis in his sleep.
Why Darth Vader Made Palpatine More Powerful
Ultimately, this leads to Anakin Skywalker/Darth Vader. Palpatine was at his most powerful with Vader as his apprentice because of how strong Anakin Skywalker was as a Jedi on his own merits. Beyond that, there are other factors to consider. Vader’s robotic body kept him strained, unable to tap into his full Force abilities (and, logistically, his breathing mask prevented him from stealthily killing Palpatine in his sleep). Vader’s anger with Palpatine, including being unable to save Padme’s life and the revelation that his son was alive, makes his resentment grow and therefore fuels Palpatine’s strength.
This is why Vader needs Luke to defeat the Emperor. He initially offers an alliance, knowing that, together as father and son, they can defeat the Emperor. This might explain why Palpatine is so calm when threatening to turn Luke into his apprentice and replace Vader right in front of him. Either way, Luke’s anger over having to kill his father will make Palpatine strong as his new apprentice, while Vader’s resentment will only grow if he is forced to kill his own son. This additional context contributes even more to the original trilogy’s dynamics.
In the end, Luke and Vader defeat Emperor Palpatine in Return of the Jedi, but not because of Vader’s plan to become the new Sith Lord. Instead, he ultimately acts out of love for his son, robbing the Emperor of his greater Dark Side power. Vader’s last act rejects the Sith Rule of Two and instead embraces the Jedi’s rule of a master passing on their knowledge (and sometimes their life) to save an apprentice, as Qui-Gon Jinn did for Obi-Wan, and Obi-Wan would later do for Luke Skywalker. Luke Skywalker would continue this journey, sacrificing his own life to save and empower Rey.
The Rule of Two might have been great for keeping off the Jedi’s radar for years, but it also led to the Sith’s defeat. A Sith master and apprentice could never be truly united, as opposed to the Jedi, who work together to pass on their knowledge, not hoard it. In the end, the Sith lose because of their own thirst for power.