User blog comment:Draevan13/Differences between books and series/@comment-5385005-20120808162633

The biggest issue in any adaptation is how well they replicate the story. Season 1 told a story about conflicting values just like Game of Thrones did and Season 2 told a story about conflicting loyalties just like Clash of Kings did. So, they have done well so far. Season 3 is a story about Conflicting Love and Hate: let's see how they do there!

Plot details have changed, but those are just trees in the forest of story. In some cases, they have been necessary: for example, if you are going to elevat Robb Stark to a protagonist (he's a secondary character in the books), then you have to change his plot-line, as it does not feed the story in the books. But I cannot imagine trying to do the TV series without recreating Robb Stark as a protagonist.