Having watched the movie Insurgent in theaters, I decided to read the book after the fact and compare them. I was amazed at how different they were. When I went on IMdB and looked at the trivia for the movie, there was a piece that said they decided to go with a completely different plot than the book but it was still in the same world. I've noticed this happening more and more recently. The Walking Dead is drastically different from the graphic novels -- but the writers call it the "same world." Same with Under the Dome. Stephen King didn't want to make the book into a tv show -- he wanted to use the opportunity to create a new plot in the same world. What does everyone else think of this? Do you prefer movies/tv shows stick to the original plot of the book they're inspired by? Or do you enjoy the different plot, as a way to experience the book you love in a different way? Personally, I wish they'd just stick to the damn book most of the time...
There can be lots of reasons for this. Back in the day, when I was a wee lad, one of the strongest restricting factors for film versions of books was time. There was a time, not long ago, when 90 min was THE LAW. Anything longer would be hacked or not shown in "major venues". David Lynch's DUNE is a prime example. The book was far too complicated to make happen within the span of 90 min so the director clearly opted for the same world, but a rather different story. The story is correct in the very broad strokes, but it misses so much. The SyFy Channel rebooted the book as a miniseries staring William Hurt as Duke Leto Atriedes, and I had so much fanboy expectation because there was a real actor at the helm of the story, and they did stick to the actual story, but the story fell flat on its face. Was it because it got a shoddy treatment at the hands of SyFy Channel? Maybe. Was it because Hurt was the only real actor in sight? Maybe. Or, does the story and the intrigue and the level of attention to internal dynamics of certain characters and certain kinds of characters just not lend itself to being reproduced on the screen? I think that's part of it too. When I read Frank Herbert's books, I was able to flesh out the characters myself, and what's more, I was able to mull over the idea of being a kwisatz haderach or a Bene Gesserit Reverend Mother or a Stage Three Guild Navigator or a Mentat or a Face Dancer. I was able to pause and digest these things, put the book down, let the ideas flower within me, and then return to the story with these things more firmly brought to fruition within my mind. Because of that, Frank Herbert's DUNE is also Wrey Fuentes' DUNE, for me, in my read, and yes, the same holds true for any book, but I think some books suffer more from the removal of the respective personal interpretations than other books. </ramble>
If they do a good job with it, I'm not opposed to a TV show developing different plots and story lines in the same world. That's a big if, but if they do it well then you get a whole separate set of stories in addition to the books (which usually beat the show anyway).
I like how the Walking Dead does it. They have some original characters and some tv show creations. People die in different ways, new things happen. It keeps even the biggest fans on their toes, not knowing exactly what's going to happen (same work GoT). I despise Under the Dome. It could just be the horrible acting, but mostly, the sense of urgency is gone. The book was so intense because they were running out of supplies and the air quality was poor. But since they dragged out the timeline in the show, it's just not the same. I really dislike the Insurgent movie compared to the book. Despite the horrible writing, it was intense. There was drama and generally a good plot. And the movie essentially lost all of that. I remember thinking after watching the movie, "why would the creators of the city hide their message in a box that could kill people?" It didn't make sense to me. Well, in the book, there is no box. It's just a file on a computer. I guess there can be benefits and disadvantages to either strategy. Just depends on the story.
Other books->film, though, I'm never sure why they go the routes they go that differ from the original book. In Michael Chabon's The Mysteries of Pittsburgh, two important characters from the book, Arthur Lecomte and Cleveland Arning, are melded into a single character (Cleveland), which drastically changes a lot of the motivations of the MC, Art Bechstein. In the film version, there's a blink-and-you'll-miss-it cameo of the character that should have been Arthur Lecomte, giving one cause to believe that maybe he was part of the film, but later they chose to pour him into Cleveland Arning. *shrug* Who knows....
Also, in Jonathan Safran Foer's Everything is Illuminated, the film version completely omits the mythologized origins of the shtetl of Trachimbrod (ZofiĆ³wka), which robs the film version of its Magic Realism aspects, making other facets of the book that do make it into the film feel random and untied.