Game Of Thrones fans are obsessed over the differences between George R.R. Martin's 'A Song Of Fire And Ice' and HBO's 'Game Of Thrones'. Casting for a show based on a novel is never easy as it limits the stretch of the imagination. David Benioff and D.B. Weiss said that the only character they found it easy to cast was King Robert Baratheon's role when they came across Mark Addy's audition, which they said was the first video in an archive of auditions they clicked on. Aside from that, the only character still left on the show that didn't have to audition at all was Peter Dinklage as Tyrion Lannister. Let's take a look at how well they cast these Game Of Thrones actors!