When Disney acquired Lucasfilm in late 2012 they accompanied the announcement with plans to continue the Star Wars with Episode VII leading an entirely new trilogy. J.J. Abrams was tapped to direct relatively quickly, the first choice of Lucasfilm's new boss Kathleen Kennedy, and an ambitious release date was set for summer 2015. No time was to be wasted.
Abrams and the crew needed more time to do what they needed to do and the film was delayed to holiday 2015 and a few key things happened during development. Harrison Ford sustained a serious leg injury and the writers of the film changed as Abrams and Lawrence Kasdan (The Empire Strikers Back, Return of the Jedi) rewrote the script. How did these happenings alter the story of Star Wars: Episode VII - The Force Awakens?
NOTE: The following post contains MAJOR SPOILERS for Star Wars 7
When Arndt's script was scrapped, according to the trades, Abrams' new story favored older characters and more focus on original characters. That of course ended up being Han Solo and Chewbacca having key parts alongside the saga's new leads. And for Luke, that meant practically no role at all when it comes to screen time, even if he's central to the plot.
Over the weekend, as Star Wars 7 crushed box office records, many details were revealed about the script and its evolution, including which new character was going to be killed off. Much of this came from the film's writing team Abrams, Arndt, and Kasdan hosting a screening and Q&A on Saturday where they talked about R2-D2's seemingly inexplicable awakening and convenient knowledge, and how Luke Skywalker's role was altered to make him the MacGuffin of the film - a plot device the protagonists of a story are after.
Star Wars 7 wasn't always going to be about the search for Luke, specifically. Recall: the question that made J.J. Abrams agree to do the movie was the simple question of "who is Luke Skywalker?" But Star Wars 7 isn't just about the end game of finding out where the aged Jedi is and bringing him back to help the Resistance. It's really about finding what Luke has also been searching for: the original Jedi temple(s). That's likely to be central to the new trilogy and the Luke vs. Snoke conflict.
We learn from Han Solo explaining Luke's absence to Finn and Rey that after his Jedi Academy was ruined by Kylo Ren, that Luke went to search for the first temple of the Jedi. That could potentially explore the prophecy of the prequels about the chosen one who will bring balance to the Force, an idea that's inextricably linked to the Skywalker lineage which began with the miraculous creation of Anakin Skywalker (who has no father).