Star Wars has once again retconned the Sith Rule of Two. As seen in Star Wars: Episode I — The Phantom Menace, Master Yoda was deeply troubled when he learned Qui-Gon Jinn and Obi-Wan Kenobi had encountered a Sith. "Always two there are," the diminutive Jedi Master observed.
"No more, no less. A master and an apprentice." It was eventually revealed the Rule of Two had been imposed by Darth Bane a thousand years ago, because he realized a multitude of Sith inevitably led to in-fighting.
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