This is the first episode in the series written by George R.R. Martin, and the first screenplay which Martin has written in almost a decade and a half (although the "Not today" lines and Drogo's fight scene were inserted by showrunners David Benioff and D.B. Weiss). On the commentary track, Martin relates that prior to Game of Thrones, he was never allowed to adapt his own work to the screen, since original authors are supposedly too close to their own material.
Like the novels, the fate of Syrio Forel after his duel with Meryn Trant is left ambiguous. Maisie Williams later asked the show runners David Benioff and D.B. Weiss if Forel could have survived, but they replied "No, he is dead."
George R.R. Martin wrote in a montage of various Northern lords receiving Robb's call to arms, which included a beer-drinking Greatjon enthusiastically reading his letter and Roose Bolton casually flaying a man when the news reached him. This was cut because of the extensive cost of hiring actors to play the lords, constructing sets and CGI-elements like castles.
While walking through the woods with Bronn, Tyrion whistles Beethoven's 6th Symphony (the Pastoral Symphony).
The episode title refers to the lesson about fighting Jon gave to Arya in The Kingsroad (2011): "stick them with the pointy end."