Star Wars: 12 Stupid Decisions From The Prequels That Actively Ruin The Originals
10. The Rule Of Two
It's a common misconception that the notion of Sith (as opposed to Jedi with a Dark Side affiliation) wasn't introduced until the prequels. Now that's completely wrong; it wasn't spoken on screen until then, but not only was it present in the Expanded Universe during the nineties, it also featured in Lucas' early draft for Star Wars. Besides, isn't Darth just an amalgam of Dark Lord of the Sith?
But while the existence of a Sith Order opposed to the Jedi was established from the off, many of their more specific traits weren't introduced until later. And although most of the alterations are fine (they all have red lightsabers because it's a "bad colour), some have a negative effect on the originals.
Take the Rule of Two. From The Phantom Menace onwards it's established there can only ever be two Sith, a Master and an Apprentice, but the constant focus on it turns the entire finale of Return Of The Jedi into a mess of allegiances.
Both Vader and Sidious know in broad terms that to turn Luke one of them will have to die, yet they both are clearly working together. It's as if they envision a situation where all three of them can work together, which was fine until the Two gumbo got involved.