HBO - Game of Thrones SPOILERS INSIDE. you have been warned

[Breand]

That is what causes the Oberyn situation. A non character in the books become so important to the show simply because the main characters aren't getting enough air time.

Again, I think a brilliant move on the showrunners part. Book readers know that Dorne will play a much bigger role as the series goes on, so this was a great way to get viewers a baseline of knowledge about Dorne as the new story lines unfold.