Gotham Knights is an upcoming video game starring several members of Batman's extended team, the Bat-family. The Gotham Knights creative team at WB Games Montreal already has a solid history of creating titles in the Batman universe, as they are the same people who made the Arkham Asylum line of games, though Gotham Knights is set to be in a new timeline separate from that series.
Batman himself is seemingly deceased in Gotham Knights, so the role of the main character falls to four of his closest allies: Nightwing, Batgirl, Red Hood, and Robin. With four different playable characters at work here, and with Gotham Knights set to be a little different based on which one the player chooses, it would be a good idea to cover a bit of the backgrounds and histories of each of them.
Dick Grayson Is Gotham Knights' Nightwing
Dick Grayson was once a member of the Flying Graysons -- a family of trapeze artists who performed in Haly's Circus. Due to trouble between the circus' owner and the Gotham Mafia, Dick's parents were killed during a live performance. Bruce Wayne was sitting in the audience of the performance that night and, seeing a young boy with his life turned upside-down by crime as his own had been, Bruce adopted Dick as his ward.
Knowing that Dick would seek revenge against the Mafia that took his parents from him, Bruce decided to make sure he would be safe. He trained Dick in self-defense and the difference between revenge and justice, eventually leading Bruce to take on Batman's first sidekick, Robin. Batman and Robin fought crime together side by side for many years until Dick Grayson outgrew the Robin name and became Nightwing, a superhero in his own right. Nightwing mostly operates in Bludhaven, another city close by to Gotham, but he still helped out Batman whenever he was needed.
Barbara Gordon Is Batgirl
Barbara Gordon is the daughter of Police Commissioner Jim Gordon, one of Batman's greatest allies over the years. At a young age, Barbara was frustrated by the corruption of the Gotham City Police Department, and when Batman started working outside the law in order to help the city, Barbara found inspiration in the hero's methods and goals. Eventually, she created the persona of Batgirl and started operating as a superhero on her own, but eventually, she caught Batman's eye, and they officially teamed up.
Later, Barbara was shot and paralyzed by the Joker, ending her career as Batgirl. From there, Barbara changed her superhero moniker to Oracle and began to help Batman from behind a computer screen, working as a hacker and information gatherer. Though this new role was very different, it was no less important to Batman's efforts in Gotham.
In recent comic book canon, Barbara has had her paralyzation healed, either by having it explained as a temporary injury or giving her a special state-of-the-art surgery. Because of this, she has returned to her former Batgirl persona.
Jason Todd Is the Game's Red Hood
Very shortly after Dick Grayson retired from the role of Robin, Jason Todd was caught by Batman attempting to steal the tires off the Batmobile. Impressed with Jason's spirit, and seeing a lost, angry boy who needed help to stay off the streets, Bruce brought Jason into his home and trained him to be the next Robin. Unfortunately, sometime later, The Joker kidnaped and murdered Jason.
Jason Todd remained deceased in the comics for many years, until he was resurrected in a Lazarus Pit by Batman's enemy, Ra's Al Ghul. Jason Todd returned to Gotham and took on the guise of a mysterious anti-hero called Red Hood. Jason's methods and goals as the Red Hood made him a more extreme vigilante who was willing to kill, as he hoped to reduce crime and make Gotham safer. Jason Todd and Bruce Wayne eventually reconciled, and Red Hood changed his methods to be more in line with Batman's, making him a vital member of the Bat-family.
Tim Drake Takes On the Iconic Role of Robin
As a young child, Tim Drake was present at Haly's Circus on the night that Dick Grayson's parents were killed. He spoke directly with Dick before the show, and later caught a glimpse of Batman consoling Dick afterward. Years later, Tim witnessed Robin fighting The Penguin using a move for which the Flying Graysons were famous. Tim Drake was incredibly intelligent even at that age, with detective skills that could one day rival Bruce's own with time and training. Therefore, Tim was able to put two and two together, and accurately deduced the secret identities of Batman and Robin at only nine years old.
After Jason Todd was killed, Tim believed that Batman needed a Robin to deal with the grief, and since Dick had already adopted the Nightwing persona, Tim revealed himself to Bruce and offered to take the role. Bruce was impressed but needed Tim to prove himself, which he eventually did. Bruce and Tim worked happily together as Batman and Robin for many years. Though he has since passed along the Robin mantle within the comics, it seems that in Gotham Knights, he is still active in the role.