- "You can't beat me, Bruce, you need me! I’m the villain of your dreams; the shadow within your shadow, the tumor lurking in your soul."
- ―Joker as a villain[src]
- "From the start, John has hung on your every word, bent over backward to please you. Your influence is everywhere in him, even the part of you that is darkest."
- ―Alfred warning Bruce of the "Vigilante Joker"[src]
The Joker is a clown-themed criminal/vigilante operating in Gotham. Initially a patient at Arkham Asylum known as "John Doe", Joker became an ally to Bruce Wayne while he was incarcerated at the asylum. After he was discharged from the asylum, Joker went on to associate with a group of criminals called The Pact, whom he wished Bruce to get involved with. After the group disbanded, the actions of Bruce/Batman affected the Joker, ultimately becoming one of the greatest threats Batman has ever faced.
Nobody truly had an identity for the Joker, with the name "John Doe" that was given to him by the asylum staff. It seemed that John was also unaware of his past and didn't remember his life prior to Arkham, how he got there or even his own name. No one even remembered the day that John arrived and there was no record of him ever being committed to the Asylum. Other inmates were scared of him, particularly Victor Zsasz, who found him unpredictable. However, to staff members, particularly doctors Joan Leland and Harleen Quinzel, John seemed to recover and was one of the more cooperative of the inmates.
While at Arkham, John became obsessed with Bruce Wayne and his activities in the public's eyes. He also began to admire Batman and his war against crime, particular criminals like Carmine Falcone. John kept a scrapbook of information and became determined to learn everything about Bruce. It's possible he deduced that the billionaire was Batman before their first meeting.
John was also aware of Thomas Wayne's actions and the involvement Arkham Asylum. Theses included his murder of the Arkham family and the fate of their daughter, Victoria. During the Children of Arkham's attacks on Gotham, John remained quiet on the information he knew, including the storage of the Children of Arkham's chemicals.
When Bruce was committed to Arkham Asylum, John came to his rescue by assaulting two other inmates that were attacking him. When Leland arrived, John tried to pin the fight on Bruce, claiming that he had fought them off single handedly. He remained present whilst the billionaire was introduced to the staff, accompanying them out of the cell.
During the journey to the lobby, John conversed with Leland, though he kept his eye on Bruce to keep him away from some of the other inmates. He also bullied a number of inmates, including one that tried to use the phone. After they arrived in the Lobby, John forced "Sane Lewis" out of his seat and left to get the television remote from Leland. Before he left, he gave Bruce a key. When he returned, John turned over the TV to the Gotham City News Channel, where he watched various reports about Harvey Dent's actions as mayor.
Whilst watching a report about Vicki Vale's disappearance, John revealed his knowledge of her identity as Lady Arkham, a piece of information that he suspected Bruce also knew. When Bruce confirmed his mutual knowledge, John offered to help set him free, noticing a "darker side" to him. He revealed her past as a member of the Arkham family and the motivations for her crusade against Bruce. John offered to set Bruce free, but asked for a favor in return. Regardless of whether Bruce agrees to it, John started a riot by cutting Zsasz, giving him a "tally mark" and a knife. This lead to the serial killer striking out at another inmate, distracting the orderlies long enough for Bruce to make a phone call. If Bruce does so, John tells him to investigate Vicki's adopted parents, the Vales, and wishes him luck with the investigation.
Some time after the riot, John was returned to his cell, where he caught Bruce leaving with his butler. As he passes him, John either reminds him of the deal or tells him to investigate the Vales, depending on whether he went through with his plan.
When the Children of Arkham instigated a breakout at Arkham, John was among the inmates set free. However, unlike the others, he was not involved in the chaos and simply watched it unfold. After watching Batman defeat Zsasz, John congratulated the vigilante. When the GCPD stormed the dining hall, John remained calm and allowed them to take him into custody.
In the following week, John was discharged from Arkham, being able to manipulate Leland to sign the documents. It was possible that he had organized the attack at Commissioner James Gordon's rallying event. Regardless of his guilt, John watched the event at the Stacked Deck, during which he saw either Bruce or Batman subdue the assailant. Entertained by the events, John promised to either see Bruce again or out-perform the attack.
During his year of freedom, John claimed to have found it hard to readjust to society. However, he also became acquainted with some of the world's most dangerous criminals and formed a group known as the Pact. Due to those connections, John became one of the most wanted people in the world for The Agency and its director, Amanda Waller. After an attack on Wayne Enterprises orchestrated by the Riddler, John decided to invoke the favor from Bruce, though the reasoning behind this remained unknown.
Attending the funeral for Bruce's friend and attack victim Lucius Fox, John talked with the dead man's daughter, Tiffany Fox. Making a number of inappropriate comments and jokes, he gave Bruce a “Get Well Soon” card that he bought and the two took their places in the pews as the sermon began. During that, John asked him to meet and join the Pact as the favor. Mentioning Riddler in the conversation, he gave Bruce information about his operations in the East End of Gotham. As the funeral finished, John decided to leave, leaving some parting words to the billionaire. Bruce can use the opportunity to attach a tracking device to John, which he seemed oblivious to notice.
Later, John texted Bruce information about Riddler's East End hideout and suggested interrogating Rumi Mori, an arms dealer the criminal had been working with. After giving the information, John cut off the conversation to take care of other matters. It was unknown whether John was involved with one of the Pact's attacks on Gotham, though it's possible he may have assisted either Mr. Freeze or Harley Quinn.
The following morning, John was either followed or contacted by Bruce, who decided to take up his offer to join the Pact. Found at the Stacked Deck in the middle of "group therapy" with Willy Deever, John finished the session to meet with the billionaire. If Bruce placed the tracking device on him, John reveals his knowledge of it, expressing his annoyance at doing such, but seemingly forgave him for placing it on him. During the conversation, John admitted to having lied about Riddler's involvement with the group, though denied responsibility in his murder. He promised not to have any more secrets between him and Bruce, offering a pinky swear. While John contacted Harley to let her know, Willy tried to attack Bruce. If Bruce choses to subdue Willy, John will record the incident. Regardless, they left to meet the other members of the Pact.
After he received a text from Harley that let him know that she was interested, John told Bruce about what was decided and revealed his feelings for her. Stealing a car, he attempted to hotwire it and introduced Harley when she arrived. At Harley's request, John collected a slushie for her, allowing Bruce time to convince her of his motives. After the diversion, he drove to Wayne Enterprises, where Quinn wanted Wayne to steal the Phalanx Key for their operations. Though they initially promised to stay put, John and Harley followed Bruce to his office, knocking out a security guard and menacing Chairwoman Regina Zellerbach as they went. When they arrived at the secret lab and vault, he looked around at the various tools and gadgets, including an EMP Generator. When Bruce finally got into the vault, John stayed behind with Harley, but later followed when he wondered what went on. Depending on whether Bruce lied to Tiffany at the funeral, the following will occur.
If Bruce told Tiffany the truth about his involvement with Lucius' death, John discovers them in conversation. Tempted to tell Harley, Bruce convinces him to keep quiet. Depending on whether Bruce is able to get Tiffany to hand over the key, John will either take the key to Harley, gaining her ire, or is stunned during an escape attempt. If the latter plays out, he is present whilst Harley threatens Tiffany and forces Bruce to pledge allegiance to the Pact for her safety. After Bruce either accepts or denies, John finds and hands the key to Harley to distract her. As they leave, Harley asks him to bring the EMP generator with them, having decided to use it for their next attack.
If Bruce lied to Tiffany, John will be stunned with a taser as he enters the vault. He is present whilst Harley threatens Tiffany and forces Bruce to pledge allegiance to the Pact for her safety. After Bruce either accepts or denies, he finds the Phalanx Key and gives it to Harley to distract her. As they leave, Harley asks John to bring the EMP generator, having decided to use it for their next attack.
After returning with Harley, John was able to convince the other members to meet Bruce as they prepared to retrieve Riddler's body from the Agency. He contacted Bruce to give him an address to meet, sending some men to bring him to their lair. Whilst Bane and Harley argued whether to induct him into the group, John activated the EMP Generator "accidentally" to prevent the former from killing the billionaire. When Harley tasked Bruce with getting the approval of Bane and Freeze, John was approached for advice to gain their favor. Though he had no idea how to get Freeze's approval, he gave him a bottle of beer to get Bane to talk. When the group voted on whether to grant Bruce membership, John voted for him, resulting either in a tie or a majority vote.
During the attack on the Agency, John remained within the escape vehicles as Bruce and the other members engaged the agents in combat. He helped load Riddler's casket onto the back of the escape vehicle and remained out of combat. John, like Bruce and Freeze, was among the members to flee the scene as the GCPD arrived. Depending on whether Bane or Harley were left behind, he will either help open Riddler's casket or leave to mourn.
Depending on whether Bane or Harley were left behind, John either helps collect the payment for Catwoman or stays in his Ha-Hacienda. When the Pact member returned from the fight, John watched the ensuing confrontation that resulted in Quinn's takeover of the group. When Harley gave Bruce the task of investigating Riddler's hideout to find information about an Agency black site, she suggested that John help him. After he changed into something more suitable, they and Catwoman left to investigate the lair.
After their arrival, John and Catwoman left to investigate the outside for GCPD officers while Bruce checked the back. After they returned, he attempted to break down the fence with a crowbar, only for Bruce to intervene and take over the task to avoid attracting attention. While he investigated the scene, John and Catwoman remained outside and only entered when Bruce was confronted by Harvey Bullock on the scene. When John retrieved the crowbar to knock Bullock out, Bruce either allowed him to do so or dealt with Bullock himself. Regardless, the three entered Riddler's lair and began their investigation.
While Catwoman investigated the balcony, John and Bruce searched the lower area of the hideout and uncovered a trap that was left behind by Riddler. Bruce also interacted with John, during which John told him about his distrust for Catwoman and about some of his history. When Bruce was able to solve Riddler's trap, he and Catwoman insisted that John stay behind while they investigated the uncovered elevator. When Catwoman tried to escape with the decryption drive, John only watched as Bruce attempted to stop her and took photographs with his phone. After the battle, John heard Catwoman mention her intention to steal a laptop in Harley's possession and decided to confront Bruce about it, but somewhere else other than Riddler's lair.
After he took Bruce to Café Triste, John ordered them drinks, which included a frappe for himself, and confronted Bruce on telling Harley about the laptop. John pondered telling her to improve her opinion of him but ultimately decided against it. After he witnessed some flirting between Bruce and Catwoman, John asked Bruce for some advice to help Harley notice him. Depending on whether Bruce advices to be himself or manipulate her, he either goes through roleplay potential scenarios with Bruce or uses impromptu Rorschach tests to find out more about the billionaire. When Bruce decided to leave to "attend to another matter", John allowed him to leave and promises to pay for the drinks. Depending on how he answered, he will decide whether to help him steal the laptop. After Bruce left, John noticed the Batsignal shining, leading him to either realize he was actually Batman or finally giving him proof of suspicions.
Deciding to help him, John followed Batman to the rooftop of GCPD Headquarters and got the Dark Knight's attention by making shadow puppets with the Batsignal. After he introduced himself for what seemed to be the first time, John offered to help Batman arrest the Pact and retrieve Harley's laptop. However, John promised only to do so if she was left alone. John and Batman arranged to meet up behind the Stacked Deck if he was successful, which John agreed to do. After that, John took a selfie with his phone and showed it to Batman, with Batman either allowing him to keep it or destroying the phone. If the latter was chosen, John was shocked at that action and expressed his disappointment for losing it.
When Bruce returned to Old Five Points, John talked to him and advised that they used the opportunity to steal the laptop. When Harley came over to check on them, John tried to offer to help her search for the Pact's mole, only to be turned down and dismissed. While Harley and Bruce talked, John slipped into her office in order to retrieve the laptop for Batman. Depending on whether Batman told Catwoman about Gordon's ambush, John either didn't find it (if Catwoman was informed) or was able to steal it (if she wasn't told).
- If the latter played out, John met with Batman and gave him the laptop. While John commented about feeling conflicted about stealing from Harley, he was pleased for having helped Batman and asked for a lesson in throwing a Batarang. If Batman agreed to do so, John received a demonstration on how to do it and was given the opportunity to throw one, unsuccessfully. After practice concluded, John asked to keep the Batarang that he practiced with, something which Batman agreed to. As Batman left, John promised him to stay out of trouble and help him, whenever he needed it.
When Harley discovered that the laptop was missing, John assisted her in investigating the culprits. During the final preparations, John was given Riddler's position as "tech guy." If Harley did not find out about Tiffany or Project LOTUS, John also told her about those. After John learned that Harley had narrowed it down to Bruce and Catwoman, he begged her to let him interrogate Bruce and received some advice on what to do with her. When John finally interrogated Bruce, he worried about what they were going to do and suggested that they pin the blame on Catwoman. When Harley returned, John, who claimed to have finished, told Bruce to tell her who the mole was:
- If Bruce blames Catwoman, John is pleased that he followed his advice and receives praise and affection from Harley for getting the information out of him. He also witnesses the rest of the Pact's attempt to kill her with one of Freeze's devices, but is otherwise not involved. After placing her in one of Riddler's death traps as a temporary cell, he, Bruce and the rest of the gang leave to raid the black-site.
Depending on who was given up as the mole, the following happened:
- If Bruce chose to follow John's advice and blame Catwoman for the theft, he mostly stands by to observe whilst Bruce and the others battle employees of both the Bohdi Spa and SANCTUS. During the raid, he also takes a picture of the group on his phone to mark the occasion. John will also catch Bruce communicating with Amanda Waller, but seems to remain oblivious to it, dismissing the action as him talking to himself. Knowing the Pact have come together to get their hands on the virus, John shares with Bruce his belief that they will disband once they get their hands on it.
- When asked to install one of Riddler's drives, John's supposed misunderstanding causes his position to be given to Bruce. He was amazed at Bruce's actions during the battle, including drawing a turret's fire to allow Harley to destroy it. When Bruce gets separated, John and the rest of the Pact are forced to disable another turret and, as he tries to destroy Project LOTUS, watches as Bane tries to stop him from doing so. When Bane comes close to killing Bruce, John interferes and attacks him, allowing the billionaire to subdue him. When Harley betrays the group, John is shocked by her leaving them behind and flees the scene as the Agency arrives.
After the raid, John fled back to Old Five Points in order to hide from the Agency, only to find their operatives already there. After he hid in a place that they could not find him, John watched as they stole Riddler's blood, from both his corpse and the samples that were collected by Freeze. Eventually, John was discovered by Harley, who returned to retrieve the samples and synthesize a usable version of LOTUS. After he told her what he'd seen, Harley rejected John and gave him a black eye before she fled. With his feelings truly broken, John broke into Harley's Office and drank himself into unconsciousness.
Eventually, John was discovered by Bruce and Special Agent Iman Avesta, who returned in search of Quinn. After he was woken up, John drunkenly introduced himself to Avesta and ranted about his perceived one-sided friendship with Bruce. John blamed Bruce for the advice that he had given him to win over Harley and showed his frustrations about how the Pact had been disbanded. As Bruce tried to get more answers from him, John drew a gun on him and Avesta and was talked into dropping it.
As John attempted to leave, Avesta blocked his entrance while Bruce talked him into telling them about what had happened. Though reluctant to help them find Harley, John was talked into doing so but insisted on doing so alone. Regardless of whether Bruce chose to let John go alone or join him, John left to find Harley by himself. If Bruce insisted that he joined John, John held him and Avesta at gunpoint before he fled and ensured that they did not follow him.
John eventually tracked Harley down to the defunct Bonus Brothers Carnival, where she had stored one of the GCPD's armored vehicles after the attack on the Agency convoy. After he informed Bruce, John investigated the Funhouse where he and Harley had set up a lair and discovered multiple agents there. John murdered the agents, though he claimed it was only in self-defense. Eventually, John was discovered talking to the agent's corpses by Bruce, who came after he was given the lead to follow.
After he was discovered, John claimed that he was attacked by the Agency and, succumbing to something dark building up inside him, had bludgeoned them to death with the nearest object that he could grab. However, Bruce found multiple holes in the story, including a gunshot wound to an agent's back. Depending on dialogue chosen, John and Bruce's "friendship" either improved or decreased. During the conversation, John revealed that he knew that Bruce was actually Batman and deduced it some time ago. If Bruce didn't acknowledge that to be true, John gives evidence to support his claim, including actions that he had taken throughout his time in the Pact. After he revealed that Harley had fled to the Gotham Bridge, John asked Bruce to help capture her before she did anything too drastic. John also asked Bruce whether he believed his story and promised to help if he did. Depending on whether Bruce believed John, the following possibilities happened:
- If Bruce chooses to believe John, he joins Bruce to capture Harley on the Gotham Bridge. Worried that the Agency may kill Harley, he asks Bruce to get involved and stop them from doing so. When Waller shows surprise at his appearance, he simply waves at her as Bruce talks to her. With Waller running out of options, she allows them to try and talk her out of destroying the bridge. As he watches as Bruce struggles to get Harley to stand down, John goes up and tries to talk to her himself. If Bruce lets him take over negotiations, he promises to get her to stand down. As John communicates with her. the two seem to make flirty gestures towards each other, leading Waller to suspect that he will not be successful and orders her teams to go in. Depending on the choices made, the following will happen.
- If Bruce puts faith in John and is able to prevent Waller from interfering, John is able to subdue her and hands her over to the Agency. As Harley asks him why he had betrayed her, he comments that he has been shown how to be good. When Waller asks him to hand over the virus, John refuses to, believing that it should be destroyed. When she tries to kill him, John realizes she is as bad as the Pact and calls her corrupt. He then steals a smoke grenade from an agent, which he sets off, makes an attempt on Waller's life and detonates Harley's bombs. Climbing on the bridge's railing, John promises to bring the Agency to justice before jumping off the side.
- If Bruce chooses not to let John negotiate or begins to suspect he's up to something, he takes the trigger from Harley's hand and demands that they stand down. Chastising Bruce for not trusting him, he calls the billionaire dangerous and berates him for trusting Waller. As he sees Harley being dragged away, John blames Bruce for what has happened and detonates the bombs. Standing on the side of the bridge, he embraces his madness and is praised by Harley for what he has done. He then kisses her and jumps off the bridge, the two disappearing into the night.
- Arriving in the midst of a failed negotiation between Batman and Quinn, John drives his truck into the bridge, indirectly releases Harley's bombs onto the entire bridge and causes Batman to miss an attempt to steal either the virus or the detonator. He then makes his presence known to everyone and admits his loyalty to Harley. Taking the detonator from her, he berates Batman for not helping him and calls what he stands for "a joke". Venting his frustrations, John takes control and sets off the bombs to destroy the bridge. As he watches the carnage ensue, John tells Batman that he could have prevented this destruction and how he has created him. As Harley praises him, John kisses her and jumps off the bridge, disappearing into the night.
After the events on the bridge, John decided to discard the name that he was given at Arkham and adopt a new identity: Joker. The Agency also began manhunts to find Joker and capture either Harley or Batman. Depending on the choices made in the previous episode, the Joker became either an unstable and dangerous ally of Batman or his mortal enemy. Depending on what happened, the following possibilities will occur:
- If Bruce believed that he killed the agents in self defense and trusted him enough to help capture Harley Quinn, Joker becomes obsessed with helping Batman bring criminals to justice and begins assembling his own crew to help him. With Stacked Deck patrons Willy Deever, Frank Dumfree and Lauren deciding to help him, he begins creating his own gadgets and weapons to help him and creates a new costume based around clowns and happiness. Together, the group set up base in the disused Ace Chemical Processing Plant. After several weeks, Joker sends his followers to Riddler's old hideout to attract the Agency's attention.
- When Batman arrives on the scene, the Joker attacks the agents as they subdue Batman with their stun pistols. Working together, they defeat the group, despite being severely outnumbered. As Joker introduces Batman to his helpers, one of the agents, Roger Harrison, calls the Agency to send an asset in to capture them. As the Agency drops off the package, revealed to be an enhanced Bane, Joker tells his followers to escape whilst he and Batman deal with the criminal.
- With Bane's venom injections now lasting longer and using a tubing system as opposed to the injections, Joker and Batman find it hard to defeat the behemoth. Joker is also shocked as Willy dies trying to stop Harrison, if Batman doesn't react in time or decides to save the Agency operative instead. At Batman's suggestion, Joker either rams Bane in his Jokermobile or drops a smokestack chimney on him. As he confronts Bane, he learns that Waller has incorrectly implicated him for Riddler's death, causing him to lash out in anger. After being called off by Batman, the two leave as more agents arrive.
- Making their way to an alleyway, they are met by Alfred, who has come to help Bruce look after his injuries. Delighted to finally meet Bruce's guardian in person, John offers to help Bruce look after his injury, only to be declined. Whilst Bruce takes care of his injury using a medical kit, John converses with Alfred. After Bruce finishes, he listens to Amanda Waller's demands for both him and the LOTUS virus. Though he contemplates killing her with the virus, Joker ultimately is convinced to hand it over to Bruce to destroy it. Afterwards, he accompanies Bruce as he meets up with Iman Avesta to get blackmail on Waller. Whilst Batman meets the agent, Joker is told to stay hidden whilst he meets with her.
- After watching Batman negotiate with Waller for her to leave and possibly hand him over for an additional demand, Joker, furious at his actions, intervenes and makes his presence known. Believing that he isn't willing to do what is necessary to protect Gotham, he attacks Waller and his former compatriots in the Pact, who have now become assets to the Agency. Fighting both his former friends and agents, Joker and Batman are quickly overwhelmed and surrounded. Believing there are no other options, Joker throws two bombs towards both the Agency and the Pact, hoping that they will force them back or kill them.
- To his surprise, Batman chases after them, successfully throwing one of them to safety whilst he is injured trying to stop the other. Following this, Joker fights his way through the survivors and captures Waller, taking her hostage and fleeing. Though chased through Gotham, he manages to lose his pursuers and takes her to his hideout. Joker and his crew set up plans to force confessions out of Waller about the Agency's involvement in illegal or unethical activities, destroying both her and the organization's credit, and then execute her. With that, he plans to target other organizations, though it is currently not known which ones specifically.
- During the midst of filming, Batman arrives to save her. Joyed that the vigilante has survived, Joker pleads with him to stand by and let Waller die or help him bring down the other criminals in Gotham, using his new and somewhat twisted brand of justice. Batman refuses, causing him to question his friendship and whether Bruce is actually using the Batman identity as a façade. As he attempts to execute Waller, Batman stops him. Sending his gang to fight him, Joker takes Waller to the higher levels of the facility, hoping to get her to confess to Riddler's murder.
- When Batman arrives, having defeated his allies, Joker tries to get Waller to confess to Riddler's murder, believing that she had framed him in order to cover her own tracks. With her refusing, Joker threatens to drop her into one of the vats, only for Tiffany Fox to appear and confess to the murder. Though he initially disbelieves her, the evidence she presents causes him to realize she is telling the truth and he tries to kill her. When Batman steps in the way, Joker decides to attack him, only for him to be tackled over the railing by Waller. Before he falls into one of the vats, Batman catches him with his grappling gun, but Joker uses his own to reach one of the other walkways.
- As he tries to escape, Waller's agents arrive to stop him. Losing faith in Batman and his war on crime, Joker attacks the agents, killing them, and embraces his new identity. With Batman standing in his way, Joker engages the vigilante in a fight, the two evenly matched with their skills and equipment. Managing to gain the upper hand, Joker moves back to try to kill Waller and Tiffany, only for Batman to catch up and stop him. Chased to the control room of the plant, Joker realizes that he is destined to become a "villain" and continues to fight Batman, eventually ending with both of them severely injured.
- Finally defeated, Joker tells Bruce how much he really wanted to be a hero and asked whether he actually considered him a friend. Regardless of what Bruce says, he falls unconscious and is later found by either the GCPD or the Agency. Whilst Batman is taken away for medical aid, Gordon organizes for Joker to be returned to Arkham Asylum. Left alone in his cell, he is left to contemplate his actions. If Bruce revealed to him that he considered him a friend, he visits Joker in his cell, much to the latter's joy. However, if he was told he was an enemy, he decides to become "enemies for life" with Batman.
- Using a mole in Wayne Enterprises, Joker is able to falsify documents from Regina Zellerbach that are ordering weapons. Stealing a van, he tells his men to attract the GCPD's attention and, if they do, use an officer as a hostage, hoping to get Batman's attention. The men will eventually capture the detective he and Bruce encountered and, after restraining him, stuff a jack-in-the-box into his stomach. They then leave a weapons crate behind, with the false order from Zellerbach.
- After their informant tells them that Bruce Wayne had arrived to confront Zellerbach during a board meeting, Joker, Harley and their men attack and take them hostage. Using Willy to announce him, Joker makes his appearance, making the board aware of his relationship to Bruce and revealing to his new enemy how they had been replicating the virus. Whilst the gang put on gas masks, forcing one of them onto Bruce, Joker releases the virus, killing the enter board. Whilst Harley makes a video giving a number of outrageous demands, Joker tells Bruce how he had decided to become his ultimate enemy and will not stop until either of them are dead. He then allows Harley to knock him out and spread the virus around the rest of Wayne Tower. During this, he leaves a rag, with clues to lead Bruce to one of the bombs at Divinity Church.
- Whilst Batman deals with the bomb, Joker contacts Gordon, offering him the location of all of the bombs, in return for Batman. Gordon agrees and contacts Batman, asking the vigilante to come to Ace Chemicals. If Batman has stood beside Gordon for at least one of his actions, he tries to call the deal off, only for Joker to knock him out. When Batman arrives, Joker's men attack him and subdue him. When Joker arrives, he kills one of his men to prevent him from killing Gordon and gives him a map of all the locations of the bombs. As the former commissioner leaves to hand it over to the authorities, Joker shoots him in the legs and tells his men to move him to his car.
- With Batman now at his mercy, Joker reveals how Gordon had been only the first of his allies he would "corrupt" and how he knew he was betraying Harley, though admits that he enjoys her "the way she is". Going briefly into deep thought, he quickly broke out of it and told the vigilante how she may just activate the bombs if she is told about what had happened. After Batman referred to him as his given name, Joker electrocuted him into unconsciousness.
- Taking him back to the Bonus Brothers Carnival, Joker removes the Batsuit, replacing it with a tuxedo, and handcuffed him to one of the attractions. During him time unconscious, Joker contacts Alfred, threatening Bruce's life if he refuses to come to the carnival, and captures Tiffany, locking her within the murder mystery room. Whilst Bruce recovers, Joker makes Selina choose between her freedom and Bruce's. Having timed her answer with Bruce's entry to the room, he reveals the choice and forces him to choose whether he would try to escape himself or trust Selina with their only chance of escape. Regardless, he would force them to work together, forcing them to crawl through a tunnel of glass. When Bruce and Selina arrive in the murder mystery room, he forces them to deduce who killed each person presented. After they solve the puzzle, he reveals a trapped Tiffany and that she was Riddler's murderer.
- Afterwards, Joker and Harley present a "family meal" to the group, forcing them to play along by demonstrating Selina's shock collar. After tying them down to their chairs, Joker and Harley offer Bruce a piece of steak with a sharp object in it, which he can refuse. When Alfred arrives with scones, Joker forces Bruce to choose before hitting him with the tray. He also stabs him with a knife, later letting go after it either breaks or is head-butted by an angry Bruce. With everyone in the vicinity, Harley reveals a canister full of LOTUS, which she threatens to set off. However, Joker instead asks for them to play a game of "Never Have I Ever", forcing each other to reveal their darkest secrets.
- With Harley agreeing, Joker gives each of them rules, forcing Bruce to play along for his and his friends' lives. Forcing Alfred and Selina to reveal that they have lied or manipulated him, Joker also forces him to admit he's done the same to him. Whilst he tries to force Tiffany to admit to murder, he is distracted by her threats towards him and Harley. Trying to get Bruce to confess to "John Doe"'s murder, Joker fails to notice the billionaire cut his bonds with the knife he lost. When Harley tries to release LOTUS, Bruce turns her against him by revealing he gave the locations of the bombs to Gordon or his fixation with him. Regardless, he is able to distract her long enough to defuse the bomb and, using a Bat-Stunner hidden within one of Alfred's scones, stuns either Joker or Harley.
- With Bruce and his friends free, Joker and Harley engage them in a fight, during which he briefly incapacitates Selina with her collar. However, Bruce is able to get the controls away from him, freeing Selina and making the fight even. Using his joke weapons and gadgets, Joker is almost able to defeat them, but is forced to flee after Bruce foils an attempt on Selina's life. Chased to and cornered at another area of the carnival, Joker tries to make Bruce admit that he needs him and engages him in a brutal fight. The billionaire ultimately defeats him and continually beats him, causing him to have a catatonic heart attack.
- Realizing Joker is dying, Bruce uses a Bat-Stunner as a defibrillator, eventually reviving him. Surprised that he would actually save him, Joker tries to find out why Bruce had saved him, despite everything he's done. Regardless of the choice, he remembers the night they had shared together at Café Trisle, eventually asking Bruce whether he remembers any good things from their time together. Regardless of the answer, he stabs him with a knife he has, telling him to remember their experiences with the injury he's given him.
- Joker is later captured by the GCPD or the Agency and transferred back to Arkham Asylum. Within his cell, he plays with a doll replica of Bruce. Depending on the choices made, Joker either plays with it, pretending the billionaire has visited him, or burns it, promising to see Batman again.
During his first meeting with Bruce at Arkham, Joker seemed to be very unpredictable. He appeared bored with the order that was imposed by the staff and enjoyed chaos when it occurred. He seemed to find both the Children of Arkham's actions and Harvey Dent's wavering sanity entertaining. Joker also seemed to enjoy harmless pranks, including giving a key that didn't unlock anything to Bruce, just to see whether he tried it. According to Leland, Joker also had issues with rejection, something that was confirmed if Bruce decided not to go through with their "favor" of meeting his friends.
While he was free, Joker seemed to find it hard to adjust to freedom and seemed drawn to chaos, which led to his involvement with the Pact and falling in love with Harley. Joker also seemed to have little confidence in himself. Despite putting on a show of obliviousness and incompetence, Joker was extremely intelligent, was aware of the actions around him, and even deduced that Bruce Wayne was Batman. It also seemed that Joker had a habit of giggling when he was nervous.
Up until his identity formation, Joker displayed a contrast between a cunning, capable individual and a desperate, vulnerable wallflower. At Lucius Fox's funeral, he gave Bruce a "get well soon" card, seemingly out of obliviousness, yet subsequently mentioned his association with Riddler, knowing that he was searching for the criminal. With that, it was difficult for Bruce at times to discern whether his associate was genuinely reaching out to John or goading him. Even though John offered to retrieve Harley's laptop for him, he contrastingly proceeded to offer the same to Batman.
If Joker became a vigilante, he became overtly passionate for his crusade for justice and even exhibited frequent recklessness on multiple occasions. However, when Batman cornered him in the office, he softly confessed that this may have been a ruse in order to gain his admiration. If Joker became a villain, his personality became extremely sadistic, not shying away from disturbing acts and manipulating others to get what he wanted. Despite this, he seemed to still care about Bruce and was unable to commit himself to letting him die.
Regardless of Joker's fate, it was gradually revealed that John was always drawn to violence and chaos, whether it was for malicious purposes or for misguided lust for justice. Depending on Bruce's choices, Joker could become the most deranged and evil of his enemies or one of the most flawed, desperate to prove a point to Batman.
- Mannequin Head Bombs
- Joy Buzzer
- Utility Belt
- Grapple Gun
- Gas Pellets
- LOTUS Bombs
- "The welcoming committee has really gone downhill around here, hasn't it?"
- "You gotta be more careful, Bruce. Some of these guys bite."
- "Now THIS is good television!"
- "I’ve been watching you for a while now, Bruce. And I can tell there is something darker in you."
- "I know what you really are."
- "Ask the Vales. Ask her parents."
- "He sure does clean up well. See you soon, Brucie."
- "Oh boy, it's going to be hard to top that! But I'll give it a shot."
- "So sorry, really, it's - it's such a shame. At least he went out with a BANG, right?"
- "I told you I'd see you again, didn't I? You and me, we're two threads in the same stitch."
- "I'm going to need that favor you owe me."
- "I have this enemy. Calls himself 'The Riddler'."
- "You know, I miss this. This trust, between us."
- "So, that rude know-it-all really got what was coming to him!"
- "Who-am-I? Who-am-I? You're a rotting, stinking corpse, that's who you are!"
- "A tracker, Bruce? Really?"
- "Why Bruce...seems like you hated him even more than I did. Maybe YOU pulled the trigger. Wouldn't that be a gas?"
- "Okay, okay, here we go. I enjoyed...the lights. They had a hum to them...felt like a blanket, fuzzy even. I miss that on the outside. I-It doesn't feel...as real here, you know? Out here, chaos seems to rule the day. It's loud and--uneven. But you, Harley...you thrive on it. I can learn from that, because I thrive on you. You're my light outside of Arkham."
- "You got some real nerve, you know that, buddy? Remember the café? "Just [be yourself/manipulate her], John!" Then I stuck my neck out for you. Way out! Bane nearly ripped my head off! And for what? She flew the coop! And I have nothing! You steered me wrong at every turn! Every bad piece of advice... Everything blew up in my face!"
- "Wow, I completely redecorated, didn't I?"
- "You forget, I know you, Bruce. The real you. Always hiding behind some kind of mask. Playboy, businessman, criminal... Bat."
- "We’re two threads in the same stitch, remember?"
- "Don't struggle, Harley. They think you're a fighter, they're gonna put you in the hole."
- "Bruce showed me how to be good, Harley. In a way you never could."
- "[You say you're all about justice!/Justice?!] Justice is a joke! [You tell me what's “just” about MY life/There's nothing "just" about MY life]! I lost half of it in an asylum, to a [sickness/condition] I couldn't control- [but now, I'm in control!/and my biggest crime outside was trying to make a pal, and you betrayed me. You tell me, Bruce, what's "just" about that!?]"
- "Well, do what you have to do, old friend. Because now... The stitch is broken."
- "You could have prevented everything, instead you made me into this."
- "You corrupt pigs...you're supposed to stand for justice! But you're liars, and you're murderers, and you're so...GODDAMN RUDE!!"
- "You and me, we're gonna hunt them down together...you're all going to pay for your crimes! Batman and I, we're going to bring you all to justice! It's going to be so much fun!"
- "Sorry I'm late! Almost missed my own debut!"
- "You and me, Batman. Fighting crime! Together!"
- "Well I don't like the sound of that. She's going around telling lies. Pinning murders on me. She has to pay for what she has done!"
- "We know what you did, Waller! You're gonna regret- Sorry, sorry."
- "We’re taking the Batmobile? We're taking the Batmobile!"
- "I've seen a lot of AWFUL people since I left Arkham. But you, you're the worst! And you are going to get what you deserve!"
- "You used Batman! Blackmailed him into doing your dirty work!"
- "We've heard your excuses. You didn't mean for people to get hurt. Collateral damage, yadda, yadda, yadda. But there's one crime that can't be excused. You killed the Riddler! And then you tried to pin it on ME!"
- "If there’s one thing I learned by watching you...violence solves A LOT OF PROBLEMS!!!"
- "You both use that word "Justice" as an excuse. So you can do whatever you want!"
- "Murder is wrong.. Trust the system.. Violence isn't the answer... People just pick and choose what they believe! And you're no different!"
- "I believed in you Batman, like I never believed in anything, and it was all a lie!"
- "I was such an idiot. I was so busy looking at you. Admiring you. Wanting to be like you. Be loved by you. I lost myself. But not anymore!"
- "I guess that's it. I really wanted to be a hero, you know? But, I just...can't."
- "I know you used me. I know I should hate you. But I don't because I had such a great time with you, Bruce. Did you ever.. did you ever think of me as your friend? Like a true friend? Someone you actually care about?"
- "You.. are one messed up guy."
- "I wanted us to be friends, Bruce. But you ruined it. Now we get to be enemies. You thought Riddler was bad? Penguin? Lady Arkham? None of them knew you like I do. I know just how to press those buttons."
- "I want you to look at that scar and remember those good times."
- Joker's relationship with Bruce Wayne instead of Batman is similar to Jeremiah Valeska from Gotham, who serves as the show's version of the character.
- The name "John Doe" is a term given to male individuals whose identities are currently unknown. This was chosen to keep the Joker's past mysterious. In The Telltale Series, the credits listed John as "Joker". In The Enemy Within credits, he is listed as "John" until What Ails You, with "Joker" being used in Same Stitch.
- In DC Comics, Batman frequently has an unrelated villain who calls herself Jane Doe; the female iteration of the "John Doe" name.
- During the Vigilante Joker path, Joker mentions that the aliases he considered using included Birdman and Hawkman. The former was usually used in a name for characters in fiction, including several parodies of Batman, while the latter was a reference to the DC superhero of the same name.
- Joker's relationship with Bruce/Batman in The Enemy Within was similar to Harvey Dent/Two-Face's in the first game; friendly but changed to antagonistic, depending on the choices made by the player.
- Joker's house at Old Five Points was called the "Ha-Hacienda," a reference to his name for the various hideouts that he used in both comics and other media. In addition, the interior and death traps in his hideout in the Bonus Bros Carnival were very reminiscent of his lair in Batman: The Killing Joke.
- Some of Joker's behavior suggested that he may have suffered from Borderline Personality Disorder (BPD), with him suffering from intense mood swings, bouts of violent anger when he felt frustrated or humiliated, paranoia, and hallucinations. Joker's obsession over his interpersonal relationships, an extreme fear of abandonment, and whipping himself up into hysteria out of the very idea that Bruce would be angry with him also seemed to imply that may have been what he suffered from.
- In The Enemy Within, there was a role reversal in the traditional Joker/Harley Quinn relationship. While in most media, Joker was the dominant one and steered Harleen Quinzel toward becoming a criminal. Their relationship presented the polar opposite, with Harley the one in control and "John" being submissive and becoming the criminal Joker through her influence.
- In both endings to City of Light, "John" was shown with red lips while he watched the assassin's failure on the news. However, those were absent in The Enemy Within until his transformation into the Joker in either What Ails You or Same Stitch.
- Villain Joker's outfit is an amalgamation of variations used by the 1989 Batman film and The Dark Knight. The supposedly missing eye-brow could possibly be a reference to the version in Suicide Squad.
- According to director Kent Mudle, John/the Joker is bisexual. Telltale decided to lean into this during production of The Enemy Within and the team had purposely written homo-erotic subtext into his dialogue with Bruce.
- It is questionable how Joker was legally kept at Arkham Asylum, especially if there was no record of him being committed there.
- Joker's model is used for Tiffany Fox at the end of The Enigma, likely to direct blame for Riddler's murder towards him.