In the last episode of Game of Thrones season 6, we saw King Tommen Baratheon forbidding Trial by Combat throughout the seven kingdoms, which of course was a huge setback for Cersei as she was really counting on it. Showrunner David Benioff explains:
“This moment is a grievous blow for Cersei because she’s been counting on trial by combat really since the end of season five. This was always her ace in the hole, the Mountain was never going to lose a trial by combat there’s no one out there who could beat him. And then Tommen takes it away from her and knowing really what he’s doing. He might be a weak King, but he’s not an idiot, he understands that this move is going to mean that she’s probably not going to fare that well in this trial. So it’s a pretty devastating moment for Cersei, and you see that in her reaction, and partly because it just bodes so ill for this coming trial, and partly because it’s her own son who’s really betrayed her.”
Check out more in the video below.