Those of us who saw all the Star Wars movies as they came out have a unique perspective that won't be repeated. We had a lot of time for the SW universe to gel in our minds as being one way before the prequels and books came out (other than a VERY few books such as Splinter in the Mind's Eye).

At that point, there was nothing about the Rule of Two or midi-chlorians, or other things that became a factor in the prequel. Lucas had talked, though, about Vader betraying Luke's Father and the ensuing lightsaber duel between Vader and Obi-Wan on the side of a volcano even before The Empire Strikes Back came out. So we do know that Lucas had planned out some of the story from the start, as he claims.

But other elements seem to be thrown in. While there are retcon in-universe explanations, it seems obvious to those of us who waited so long to see more of Star Wars that there are some elements that were made up much later and explanations created to fit already filmed situations.

Some elements are understandable. Cheaper FX made it easy for R2 to fly, even though he couldn't fly in the movies that take place 20 years later. Adding an expiring warranty was an easy way to explain that.

But other elements don't always seem to fit with the original ideas, and two specific ones seem to be the Rule of Two and midi-chlorians.

It always felt like Lucas made up the whole midi-chlorian thing so there was some easy and quick way for Qui-Gon could test Anakin for Force sensitivity.

And the Rule of Two seemed to work in the prequel trilogy, but in the original, the Emperor discuss turning Luke to the Dark Side, Vader sees him as a powerful ally (and not in the context as an ally against the emperor). This entire situation seemed to be written and filmed with no awareness of the Rule of Two.

While we may never know, I'm wondering if anyone has any info on when Lucas decided to add these elements to the SW universe. Did he just decide on adding them for the prequel, or is there any evidence (interviews, comments, or anything) that indicate he had these in mind before he wrote The Phantom Menace?

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    The original trilogy doesn't violate the rule of two any more than the prequels do. Even in the prequels the Emperor trains other informal apprentices while Maul was still alive. There's also no real evidence that Vader had the attitude you attribute to him. Commented Dec 5, 2011 at 18:04
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    Sure, Lucas made up midichlorians. But he also made up everything else... :/
    – MPelletier
    Commented Dec 10, 2011 at 2:36
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    @MPelletier: Uh, yeah. Of course, but the point is to find out if they were part of the original concept or if they, like The Rule of Two, were made up later, when he started working on the prequel trilogy.
    – Tango
    Commented Dec 10, 2011 at 5:25
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    There's no need to invent midichlorians to detect force sensitivity. There are plenty of examples of Jedi and Sith remarking that "the Force is strong with this one" about Luke without needing to pull out a blood tester.
    – Oldcat
    Commented Nov 10, 2014 at 18:31
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    No, the answers don't say that. The Force was a woozy 70s mystic idea, right in tune with its time. Midichlorians is a strictly 90s kind of idea, that we measure everything with a caliper. This actually fights against a lot of what Yoda told Luke about the force in the movies.
    – Oldcat
    Commented Aug 18, 2015 at 21:16

4 Answers 4



Midi-chlorians were first conceived by George Lucas as early as 1977.

In this time the first Expanded Universe products were being created, including the ongoing Marvel Star Wars series and Alan Dean Foster's novel Splinter of the Mind's Eye. Lucas sat down with a member of his staff, Carol Titelman, to dictate a number of guidelines for these works, explaining various concepts of his universe.

Amongst them were an explanation of midi-chlorians, which Force-sensitive beings were said to have more of in their cells. (source: The Making of Star Wars: The Definitive Story Behind the Original Film)

However, Lucas did not feel he had the time to introduce the concept of midi-chlorians. The idea would not appear in any Star Wars product for twenty-two years; Lucas chose 1999's Star Wars Episode I: The Phantom Menace as the opportunity to first mention the midi-chlorians, explaining why some were sensitive to the Force while others were not, an issue that he had left unresolved since the original film Star Wars


That Lucas had planned the midi-chlorians as far back as 1977 was hinted at on the DVD commentary of The Phantom Menace, but the details would not be fully revealed for another eight years, coming to light in the 2007 book The Making of Star Wars: The Definitive Story Behind the Original Film, the hardcover edition of which had, amongst its appendices, Lucas' notes for the Expanded Universe authors.

On the other hand, The Rule of Two was a prequel invention:


The character of Darth Bane, and his Rule of Two, were created by George Lucas as part of his backstory of the Sith he developed for the prequel trilogy

The above Wikia statement's original source: starwars.com: "Endnotes for The New Essential Chronology", October 25, 2005 - archive link

The character of Bane and his secret reformation of the Sith order actually come from George Lucas' back-story to Episode I.

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    Not to be picky, @DVK, but do you know of any documentation before the prequels that specifically mention midichlorians? The reason I'm asking about that is because Lucas has a tendency to retcon his memory and reality just as he does the SW world, so I'm wondering if he's saying he had that back then or if there's anything from that time that states it.
    – Tango
    Commented Dec 5, 2011 at 22:03
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    @TangoOversway - *handwave* - George Lucas always thought what he said in the latest interview. There were no retcons. Commented Dec 24, 2012 at 23:30
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    Well, in the Lucasverse, that's true, but I have been in at least one parallel universe where there is often documentation to show there are differences between the Lucasverse and whatever universe he happens to live in at the time.
    – Tango
    Commented Dec 25, 2012 at 8:29
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    No Chance to tell us about midi-chlorians, not even when Yoda trained Luke on Dagobah?
    – flq
    Commented Aug 18, 2015 at 21:12
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    The Rule of two sounds like a TVTrope term.
    – Zikato
    Commented Aug 19, 2015 at 5:54

In The Making of Star Wars: The Definitive Story Behind the Original Film, there's a quote from a December 1975 discussion, of the in-progress fourth draft, with Alan Dean Foster (who wrote the novelisation).

I'm dealing with the Force a little more subtly now. It's a force field that has a good side and a bad side, and every person has this force field around them; and when you die, your aura doesn't die with you, it joins the rest of the life force. It's a big idea - I could write a whole movie just about the Force of Others.

If you squint a bit, that sounds like midi-chlorians - at least that everyone has the Force in some measure.

The only use of the word "midi-chlorian" itself (there's none of "midichlorian") in this book is (page 353, right at the end) an excerpt from a recording Lucas made, in July/August 1977, to elaborate on backstories for the (sequel) novelisation, comic books, and merchandising:

It is said certain creatures are born with a higher awareness of the Force than humans. Their brains are different; they have more midi-chlorians in their cells.

This is the quote that's fairly universally used as proof that midi-chlorians were an idea way back in 1977. The book is apparently constructed from various LucasFilm archive material, rather than new interviews, so it seems reasonable to assume that the author had access to the actual recordings from 1977.

This book doesn't contain any more information than this - the process Lucas was apparently using was to "role-play" as certain characters, and answer questions about them that one of his staff, Carol Titelman, would ask. The book doesn't contain the question that prompted this answer, but it seems like it would have been something like "can anyone wield a lightsaber, or does it have to be someone strong in the Force?".

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    I'm not clear of the facts in the 1st paragraph. Lucas wrote the novelization for Star Wars (or is credited, and at that time, Foster was well enough known to deserve credit rather than ghost writing). But Foster did write Splinter of the Mind's Eye, which was released later. So the December 12/75 date and Foster doing the novel for the original movie is a little confusing.
    – Tango
    Commented Dec 11, 2011 at 15:18
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    @TangoOversway Foster ghostwrote the novelisation; whether he deserved credit or not, he agreed to have it published under Lucas's name. (e.g. see his comments in this interview: cultfilmfreak.com/alandeanfoster)
    – Tony Meyer
    Commented Jan 28, 2012 at 2:27

The Rule of Two may not have been stated in the Original trilogy but it was hinted at. The Emperor says that Luke can take his Father's place at the Emperor side - implying that Vader would be replaced. Vader himself tempts Luke to join the Dark Side by saying that they could join together to overthrow the Emperor. Then Vader would be the master and Luke his apprentice.

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    Yes, but there are also conversations about having Luke join them as an ally.
    – GreenMatt
    Commented Aug 18, 2015 at 19:48
  • The term “rule of two” might origibate as a PT/TPM construct, but EU Sith of the Vader line always followed it predating TPM. The Emperor had Lumiya on ice; when Vader & Emperor were taken out of service in RotJ, Lumiya & Carnor Jax replaced them with Lumiya as master & Jax as apprentice. Commented Dec 31, 2021 at 18:54


As explained in the above link, Lucas actually hadn't come up with the midi-chlorians in 1977, despite the fact that The Making of Star Wars seemed to say that he had. According to author J.W. Rinzler:

While we were preparing the text for The Making of Star Wars, Lucas added a note to this passage about midi-chlorians, bringing his original words in line with his later thoughts and the events of the prequel trilogy.

So Lucas was playing a little fast and loose with history there. The rest of the passage in question, however, is apparently legit, including this:

It is said that certain creatures are born with a higher awareness of the Force than humans. Their brains are different. 

Lucas, by that point, had at least conceived of an alien race who were all naturally stronger in the Force than humans.

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