HBOIf you thought the attack of the White Walkers last season was a lot, things are about to get turned up on "Game of Thrones." HBO's hit drama has filmed "definitely the biggest" action sequence yet for the upcoming sixth season, writer-producer Bryan Cogman told Entertainment Weekly. "We've always wanted to get to a place — story-wise and budget-wise and time-wise and resource-wise — where we would be able to do a proper battle, with one army on one side, one army on another side," he added. And it sounds like this battle will be closer to the classic wartime scenes you're used to in movies, with CGI kept to a minimum.