The Rule of Two states that there would be only two Sith at one time, a master and an apprentice, guaranteeing that when the apprentice becomes powerful enough in the ways of the dark side to take the title of master, only then would they be worthy of the title.
Under the Rule of One, the followers of Krayt were taught blind obedience and absolute loyalty to the Dark Lord of the Sith, instead of the plotting and infighting of previous Sith organizations. Similarly to the Jedi Order, Sith Masters trained a single apprentice.
Controversy 1#: Starkiller as Darth Vader's apprentice breaks the Rule of Two. Some individuals are upset about the fact Starkiller is Darth Vader's apprentice. According to the Rule of Two, there's no way that Darth Vader should be training another Sith while Darth Sidious is still alive.
The Rule of Two states that there can no more or less than two Dark Lords of the Sith, with the greater Lord, the Master, ruling the galaxy alongside the lesser Lord, their Apprentice.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
R2-D2 has probably seen more action than all of the sequel characters put together, and has met a long list of Jedi from across time, including master Yoda. R2-D2 has even carried out special missions for the Jedi Council.
After the Sith were decimated by the Jedi Knights of a thousand years ago, Bane enacted the Sith rule of two: there would be only two active Sith at one time -- a Dark Lord to embody the power, and an apprentice to crave it.
The Rule of Two created a powerful dynamic by limiting the Sith to only one master and one apprentice at a time, although not all Sith followed the decree as some took apprentices of their own while still serving a master.
Grand Master Yoda encountered the specter of Darth Bane during the Clone Wars. During the war, Jedi Grand Master Yoda ventured to Moraband on a journey to discover the secrets of immortality. He entered Bane's tomb and encountered a fiery vision of the ancient Dark Lord.
In the Star Wars: The Force Unleashed video game, Darth Vader dispatches Starkiller to kill a number of Jedi who have survived the Great Jedi Purge. Starkiller is initially kept in secret, but he is discovered by Emperor Palpatine, he is seemingly betrayed and killed by Vader.
The Rule of Two states that there would be only two Sith at one time, a master and an apprentice, guaranteeing that when the apprentice becomes powerful enough in the ways of the dark side to take the title of master, only then would they be worthy of the title.
Kota duels with Starkiller After his training was complete, his first mission was to kill a Jedi, General Rahm Kota. Rahm Kota had survived by not using any clone troopers in the Clone Wars, instead enlisting a private militia to help fight him.
As the first Dark Lord of the Sith, Ajunta Pall founded the first Sith Empire and expanded it onto other worlds. The Sith took over the planet Ziost and created it as their capital and as Pall's new home.
According to Star Wars Legends content, the first Sith was a former Jedi Master, Ajunta Pall, who became a so-called Dark Jedi, or “Fallen” Jedi. As the name implies, these Force-sensitives chose to practice the Dark Side, and rejected the Light Side of the Force.
Early life. Darth Plagueis was a legendary Dark Lord of the Sith trained by the Sith Master Darth Tenebrous. At some point during his life, Plagueis acquired the protocol droid 11-4D.
Snoke Is Not a Sith Lord
But the fact that he's a bio-engineered being created by Palpatine explains why his training of Kylo Ren followed the Sith mold so closely, since all along Palpatine was trying to manipulate Ren.
In an early Revenge of the Sith draft, Palpatine confirmed that Darth Plagueis used the Midi-chlorians to start the cell division that created Anakin Skywalker.
"Always two, there are. No more. No less. A Master and an apprentice." — Master Yoda, speaking about the Sith.
C-3P0's memory was wiped at the end of Episode III so if he wasn't told he had no idea that his maker was the future Darth Vader. R2-D2 remembers it all and if I had to guess he is quiet sad about Anakin's turn to the dark side.
Yes, or at least Sidious intended to violate it. He wanted to change it to the Rule of One. He wanted to be the sole Force user in the entire Galaxy, an eternal and immortal tyrant ruling the known universe with no opposition that could pose a serious threat to him.
After the battle, R2-D2 and C-3PO were the sole witnesses to the marriage of Anakin Skywalker and Padmé Amidala in Lake Country. After this Padmé gave ownership of R2 to Anakin while she kept 3PO.
Obi-Wan Was Pretending He Didn't Know R2-D2
The base assumption of why Obi-Wan doesn't remember R2-D2 -- in light of the prequels -- is that Obi-Wan is feigning ignorance in A New Hope to downplay the importance of the droid's arrival.
Obi-Wan Only Says He Never Owned R2
Note that he says nothing about not recognizing R2; his clever dodge gives the impression that they're strangers but doesn't actually deny knowing the little astromech. Thus, there really isn't a "contradiction" in the first place—Obi-Wan was just being his cunning self.