Is there a reason why the writers of game of thrones are deviating so much from the books in the later seasons?

People who are A Song of Ice and Fire fans are making a really big deal about how much the show is "deviating" from "the real story". Those people must not watch very many TV or movie adaptations of books or comics, because that's always what happens.

There are two canons. There is the Song of Ice and Fire canon, and there is the Game of Thrones canon. Consider yourself really lucky that there are only two -- fans of comic book adaptations often have to deal a lot more. For example, with the upcoming Justice League movie, there's going to be three currently active canon versions of Flash or Green Arrow. I think we're up to 6 "primary" Spider-Man canon worlds, and I've lost count of how many Batman origin stories are canon. Even when the show/movie stays close to canon, they deviate, often in significant ways (there is no Tom Bombadil in the Lord of the Rings movie canon, and no Peeves in Harry Potter movie canon).

There are a lot of reasons why a TV show would deviate from the source material, and Game of Thrones is hitting almost all of them:

• Often, book material just doesn't translate to the screen; this is particularly true when there is a lot of internal monologue going on, or a lot of people thinking about events that happened off-screen. This is why Game of Thrones had to invent some minor characters -- to give them an excuse to show events or hear people talking that the novels only reveal through the first-person narrator's thoughts.


• TV shows have a fixed amount of time to tell their story. A book can be as long as the author wants, only limited by what the readers are willing to buy. And fantasy readers in particular have shown themselves willing to buy really big books (looking at you here, Wheel of Time and Stormlight Archives). There's just no way to include every character and every plotline from the novels on the show.


• TV shows have different pacing; it's possibly for a good author to hold the readers attention with very slow-burn build up to something important, and Martin is good at doing that. He can spend a lot of time putting the pieces in place for some intrigue plot. On a TV show, that would not come across nearly as well. So, plot lines often have to be condensed, dialog shifted around in time, etc.


• TV shows have to be produced on a tight schedule, based on the demands of multiple parties (the network, the production company, the actors, etc.) Thus, when the show and the books are both on-going, it's inevitable that the show will out-pace the books. The Game of Thrones writers saw this coming, and started planning what was going to happen when they were the ones writing the original material.


• People who have read the books can, on occasion, get a superiority complex about "knowing all this stuff already". That leads to people who are fans of the show getting worried about "book spoilers" (this is a real perception, real or otherwise; someone on M&TV yesterday told me he never comes to SF&F to ask about Game of Thrones because people here can't help spoiling things from the books.) If the show doesn't follow the book directly, then there's nothing to spoil. That tends to make things fun both book readers (who no longer know what's going to happen and get to find out anew), and non-book readers (who no longer have to fear someone revealing every minor detail of the upcoming season)