Authors:

Because [writers] Dan Weiss and David Benioff have done such a great job in adapting them, that's what we work with. It serves no purpose to anybody for actors to come onto a set with a well-thumbed copy of the source material and start querying why this or that line has been left out of the script. It's probably been left out for a good reason.

"Game of Thrones, Charles Dance interview: "I treat Peter Dinklage appallingly". Interview with James Lachno, www.telegraph.co.uk. March 31, 2013.
Because [writers] Dan Weiss and David Benioff have done such a great job in adapting them, that's what we work with. It serves no purpose to anybody for actors to come onto a set with a well-thumbed copy of the source