Batman: Arkham City is an action-adventure stealth video game developed by Rocksteady Studios and released in 2011 for for the PlayStation 3, Xbox 360 and Microsoft Windows. The sequel to 2009's Batman: Arkham Asylum, the story follows Batman as he works to discover the truth behind Arkham City, a super-prison comprised of Gotham City's slums.
Batman: Arkham City, like its predecessor, is a third-person perspective action video game that incorporates elements of stealth and predator tactics. The player takes control of Batman as he traverses Arkham City. Batman can use his cape to glide through the city, as well as his grapnel gun to reach high ledges.
The game uses an improved version of the "Freeflow" combat system from Arkham Asylum, in which Batman can move quickly between enemies, stringing attacks together until all enemies are unconscious. Most of Batman's gadgets can be used in a quickfire setting, adding to Batman's increased move set: he can now attack aerially, counter multiple attacks simultaneously, catch objects thrown during combat before throwing them into enemies, stun enemies to the ground, and deliver a focused beatdown attack.
The game incorporates more puzzle elements; the use of Batman's "Detective Mode", which highlights elements such as enemy skeletons and clues on-screen, is used to perform forensic analysis at crime scenes, such as tracing the origin of a sniper round. The player also has access to a criminal database that tracks the major villains across the city that is used within Detective Mode and the forensic puzzles. However, Rocksteady's art director David Hugo stated that the use of Detective Mode will be changed to an "augmented reality mode", as they found players had completed Arkham Asylum using Detective Mode all of the time. Challenges from the Riddler will also be present, but it will require additional effort to locate these, such as through interrogation of men loyal to the Riddler.
Batman: Arkham City takes place approximately one year after the events of Batman: Arkham Asylum. Quincy Sharp, the former warden of Arkham Asylum, has taken credit for stopping the Joker and used that notoriety to become mayor of Gotham City. As neither Arkham Asylum nor Blackgate Prison are in any condition to hold inmates, Sharp buys out a large section of Gotham's slums to create "Arkham City", a city-wide superprison to hold every inmate from Arkham and Blackgate. Inside the city, prisoners are given free rein as long as they do not attempt escape. Placed in charge of the facility is Arkham psychiatrist Professor Hugo Strange, who uses the TYGER mercenary group to control the city. Alongside the inmates, Strange has thrown several others into the city, including reporters and people who assisted in the city's construction. Bruce Wayne holds a press conference to protest against Arkham City only to be arrested by TYGER. He awakens inside the city to Strange privately revealing that he knows of Wayne's identity as Batman, and his plans to begin something called "Protocol 10".
Wayne is released into the city, and is quickly abducted by the Penguin and his thugs. Escaping with ease, Wayne has his suit sent into the city and transforms into Batman. Upon hacking the TYGER communications, he learns that Two-Face is about to execute Catwoman, and goes to rescue her in hopes that she will provide answers as to Strange's motives. While Catwoman is unaware of Protocol 10, she informs Batman of Strange's rumored cooperation with Joker, just before she is nearly shot by a sniper rifle. Batman traces the bullet back to an abandoned church, where Harley Quinn is holding the city's volunteer medical team hostage. He saves the hostages before using the remotely operated sniper rifle to track Joker to the Steel Mill, and heads there to interrogate the Crown Prince of Crime.
Before reaching the Joker, Batman saves a kidnapped doctor, discovering that Joker is dying from the effects of TITAN, which he injected himself with during the incident at Arkham Asylum. When Batman attempts to confront Joker, he is knocked out and infected with the Joker's poisoned blood. When Batman comes to, the Joker reveals he has sent his infected blood to every hospital in Gotham, forcing Batman to cooperate in finding the cure. The Joker says that Mr. Freeze was developing a cure but has been out of contact for some time. Deducing Mr. Freeze would set up base in the coldest section of Arkham City, Batman checks the old Gotham Police Station, where he discovers that the Penguin has kidnapped Freeze and is holding him at his base in the Museum. Batman heads to the museum and evades all of the Penguin's traps, eventually saving Mr. Freeze and a team of GCPD officers sent in by Commissioner Gordon. After fighting the undead Solomon Grundy, Batman incapacitates Penguin, who is locked up in a museum display case by Freeze in retaliation. Mr. Freeze informs Batman that he needs a restorative enzyme to finish the cure, which Batman suspects can be found in the blood of Ra's al Ghul, head of the League of Assassins. Locating members of the League in the ruins underneath Arkham City, including Ra's daughter Talia (whom Batman has a complicated romantic history with), Batman fights Ra's and takes some of his blood. During the search, Batman discovers that Strange is giving weapons to Joker's gang. In the meantime, Strange has Sharp arrested and thrown into Arkham City. Saving Sharp on his way back to Freeze, Batman learns that Strange was behind Arkham City's conception and is working with powerful individuals.
Batman brings the blood to Freeze, who completes the cure but demands that Batman first rescue his wife Nora from Joker. When Batman attempts to take the cure, Freeze attacks him. After a long fight, Batman defeats Mr. Freeze, only to discover that the cure was stolen by Harley Quinn during the fight. Freeze provides Batman with a weapon prototype to help him get the cure back, and Batman promises to find Nora in return. As Batman breaks into the Steel Mill to find Joker, who appears to have been cured, Batman is informed by Oracle that Strange has tricked the city council with the weapons he provided Joker. Claiming that Joker is planning a mass attack on Gotham, Strange receives permission to activate "Emergency Protocol 10". Batman eventually reaches Joker and fights him and his thugs for the cure. However, Strange activates Protocol 10 during the fight, causing part of the Steel Mill to collapse, trapping Batman under the debris. The Joker is about to kill him when Talia arrives and convinces the Joker to spare Batman in return for immortality. The Joker departs with Talia, leaving Batman to die.
Batman is rescued by Catwoman and realizes that Protocol 10 is the systematic execution of every inmate in Arkham City. He attempts to go after Joker and Talia, but Oracle and Alfred force him to stop Strange first. Batman reaches Wonder Tower, Strange's base, eventually reaching the control room and shutting down Protocol 10. Strange begins ranting that Batman's efforts will not stop him, but is fatally stabbed by Ra's al Ghul. Ra's reveals that he and Strange were working together, and Arkham City was Strange's chance to prove his worth and candidacy as Ra's successor. In his last breath, Strange triggers the Wonder Tower's self-destruct sequence, resulting in the deaths of him and Ra's. Batman heads to the theatre to fight the Joker, who is stabbed in the back by Talia. It is then revealed that Talia had stolen the cure off of Harley Quinn and that the cured Joker was actually Clayface. The real Joker shoots Talia, killing her and Clayface grabs the cure before attacking Batman. Batman defeats Clayface and takes a portion of the cure, but Joker then stabs him in the arm, causing him to drop the last of the cure. As Joker dies, Batman admits that he would have given him the cure, causing the Joker to die laughing. Batman carries Joker's body out of Arkham, where the GCPD are waiting to enter the city. When Gordon asks him what happened, Batman places the Joker atop a police car, walking off silently.