In an interview with Huffington Post in June, Adam Driver was discussing a charity event in which he was involved. Towards the end of the interview, he was asked to expand upon some past comments he had made about Rian Johnson:
I said what Rian had written was remarkable. He created new rules for the “Star Wars” universe and balanced the familiar and unfamiliar very adeptly while respecting that his audience can handle ambiguity.
"New Rules," eh? Possibly a completely innocuous compliment, but it is perhaps of some significance to long-time fans of Star Wars. The nerdosphere is constantly discussing, obsessing, theorizing, and analyzing every minute detail, real or imagined, about The Saga. However, maybe Driver's remark can serve as a warning to fans that they are about to be exposed to some aspects of the mythos most of us were unaware of, at least in any great detail. Such aspects are either recycled from the Legends side of things (the since de-canonized Expanded Universe), or drawn directly from the small-ish but growing list of "new canon" sources. For most casual fans, the numbered films, anthology films, and maybe the animated television shows are most of what we know about Star Wars. Note that while Legends is no longer canon, it is fair game to be mined for ideas for the new canon.
My reaction to TPM's midichlorian / virgin birth one-two punch.
Remember that feeling of getting kicked in the crotch when you first heard Qui-Gon explain midichlorians? MIDICHLORIANS? There was nothing that ever hinted that The Force was anything more than a mystical power to which some people were "lucky" enough to be connected. Now we find out that it's made possible by tiny bugs that live inside all living things, and your Force acuity correlates directly with your bug count. What the hell, man? Then Shmi Skywalker, Matriarch of Galactic Death, lets us know that Anakin's was a virgin birth. Um, okay. While it took 6 more years, it was "clarified" by Palpatine that Anakin was conceived by those wacky Force bugs. See, it all fits nicely. Later in TPM, we are introduced to "The Rule of Two" by Yoda. Again, a new concept to viewers, but at least this could be processed by the typical fan. After all, we only ever saw two Sith, so here was a history lesson as to how the Sith operate. It was new to us, but we could handle this. Besides, you were probably still too alarmed over the midichlorian thing to care about it.
So Driver's comments may indicate that The Last Jedi will reveal some new aspects of Star Wars that were previously unknown to the casual fan. Maybe even hardcore fans had only a passing knowledge of the existence of such notions from either the EU or the new canon, but didn't seriously connect them to the main story.
We will take a brief look at three potential concepts that were hitherto unknown to most casual fans, but may be a part of Rian Johnson's "New Rules".
I. Force Trees
What? Sure, Ben Kenobi told us The Force "is an energy field created by all living things." But that wizard is just a crazy old man. Did he really mean all living things? Like dianogas, and giant space slugs, and...trees? Nah, he probably just meant people. Well, maybe he did mean trees.
Our friends at SpoiledBlueMilk gathered a bunch of information from the new canon that seem to show an effort to bring forward the concept of Force-sensitive trees. Possible instances of such trees can be found in several canon sources. Originally, these instances may have been unintentional, but as SBM lays it out, you can almost retcon them so as to connect the dots and lead right up to The Last Jedi. Here, the interesting theory is that Luke may have saved a piece of a Force-sensitive tree from the grounds of the Jedi Temple on Coruscant (as seen in both The Clone Wars and Forces of Destiny). The tree would have had its lifetime to "absorb" the cumulative Force knowledge of many years of Jedi activity at the temple, and Luke could have then gleaned this knowledge from the rescued offshoot.
Not satisfied with silly cartoons as sources? A similar Force Tree may have been right under our collective noses for the last 37 years. Thanks to a Jedi mind trick from that weasel Yoda, you had always thought it was a cave in which Luke failed his Jedi drivers' test. Maybe it could actually have been the inside of a huge a Force Tree. Watch the scene again. Go ahead, we'll wait.
The bottom line is, if you're watching The Last Jedi and that crazy old man Luke tells Rey to venture into a tree so she can learn some ancient Jedi secrets, be prepared for Force Kale. It could be all the rage, two-plus trilogies after we already thought we knew everything.