This may or may not be obvious, but Palpatine never fulfilled the Rule of Two.
Sheev Palpatine constantly preaches about the Rule of Two, and acts like he was the ultimate culmination of Darth Bane’s vision. After all, he was the Sith Lord who finally brought down the Republic and wiped out the Jedi. But if you actually look at how Bane designed the Rule of Two versus how Palpatine operated, Sidious wasn't the system's greatest success. He was its ultimate parasite.
Bane created the Rule of Two with a pragmatic goal: ensuring the survival and evolution of the Sith. One to embody power, the other to crave it. The Apprentice studies, grows stronger, and eventually slays the Master.
The Master dies knowing that the Sith have become more powerful than the previous generation. It’s a brutal lineage built on legacy.
Palpatine just cherry picks his shiny toys as he sits on his high chair.
1. He never wanted a successor
Bane’s system relies on the Master accepting their eventual death at the hands of someone stronger. Palpatine had zero intention of ever dying to the hands of his apprentice and passing the torch. He didn't want the Sith to evolve; he wanted to rule forever. His entire long-term plan revolved around body-hopping, cloning, and unlocking absolute immortality.
To Palpatine, an apprentice wasn't the future of the Sith, they were just a temporary bodyguard and an errand boy.
2. He actively crippled his apprentices
A true Rule of Two Master wants their apprentice to push them to their absolute limits. Palpatine, on the other hand, constantly sabotaged his.
He treated Maul like a glorified assassin rather than a rightful heir.
He used Dooku as a disposable political pawn, discarding him the moment a shinier weapon came along.
He bound Vader into a suit intentionally designed to keep him in perpetual agony, deeply vulnerable to Force Lightning, and reliant on life support. Then the instant Vader is beaten down, he tries to get Luke to kill him off so he can make Luke as his new apprentice.
Instead of cultivating a superior dark side user who could one day surpass him, Palpatine made sure Vader was just broken enough to never successfully overthrow him. (Vader does try to overthrow Palpatine once or twice in the comics, but it also ends with Vader being humiliated back into submission. Well up until the final OG film.)
3. He diluted the Dark Side with loop-holes
To prevent his apprentices from growing too powerful, and to keep his own hands on the reins, Palpatine flooded the galaxy with secondary dark side users. The Inquisitorius, Asajj Ventress, Savage Opress(even though he took care of Savage later on)... he built an entire bureaucracy of dark siders. He effectively built a diluted Sith empire behind a thin curtain of "Rule of Two" aesthetics.
Palpatine didn't overthrow the Republic because he was a master of Bane’s philosophy. He succeeded because he was a master politician and opportunist. In the end, his intense ego and refusal to let the Sith outlive him is what destroyed them. When Palpatine died, he left no true Sith lineage behind him, just a power vacuum.
Bane built a torch to be passed down through generations. Palpatine just burned the whole room down so he could be the only thing in it.
