Batman: Arkham Knight – A Matter of Family is a story expansion where players control Batgirl, Barbara Gordon, before the events of Arkham Asylum. Set in an abandoned amusement park, Batgirl teams up with Robin to rescue Commissioner Gordon, who has been kidnapped by the Joker.

The DLC introduces Batgirl’s unique combat style, focused on hacking and stealth, and features puzzles, dual-play combat with Robin, and Joker's henchmen as primary enemies. The storyline explores Batgirl’s early crime-fighting career and her relationship with Batman and Robin.