the events that take place in the second book (A Clash of Kings).
Original gameplay is pretty much intact, except for a couple of small additions that attempt to bring Crusader Kings II closer to the world of A Song of Ice and Fire. For example, generals can have pets (like the direwolves) that will be of great assistance during battles. There is also a new, duel-based system that will let you resolve disputes by sword.
Crusader Kings 2: A Game of Thrones is a very interesting mod, thanks to which you can explore alternative scenarios within the history built by the books (and the series). What would have happened if Robb Stark had captured King's Landing? Or if Renly and Stannis had formed an alliance? Here is your chance to find out!