Detective Nicholas "Nick" Mendoza is the main protagonist and playable character in the single player campaign of Battlefield Hardline. He is a young Cuban immigrant working as a Miami Vice detective who is traveling the country to stop his former partners who have gone corrupt and bring them to justice.
— Mendoza on his father.
He would return home doing the same to his wife and son - abusing them. Until Nick's mother took him from Cuba and immigrated themselves in the United States through Miami, Florida. Nick would see the criminal base on the streets, but his mother kept him out of trouble 
Joining the Miami Police Department
Nick, seeing the crime of Miami and abuse of his father, wanted to become a real cop, he joined the Miami Police Department during the 2000's, passing through the desk with a reputation. Before joining Vice Squad, he lost two friends who were patrolmen six months prior to criminal shootings.  In 2012, Mendoza met and partnered with Detective Sergeant Carl Stoddard who taught him the ropes. As a new "rookie" detective in Miami's Vice Squad, he was under the supervision of Captain Julian Dawes.
Events of Hardline
— Detective Mendoza to Shea Dorsett in the "Prologue".
In July 2012, Detective Mendoza and Stoddard were involved in what was to be a simple drug bust but erupted into a violent shoot out. After checking for any clues, the last surviving suspect, Shea Dorsett returns to find his acquaintances dead and proceeds to run away from the scene. This prompts the detectives to chase him in a Police Interceptor and apprehend him.
After the drug bust, Captain Dawes partners Mendoza with Detective Khai. The two are ordered to locate and bring in Tyson Latchford who is distributing Hot Shot cocaine across Miami. Arriving in the Miami projects, they locate and arrest Brix. They then let him go on the condition that he tells them the location of Tyson's old friend Tap Milstein, to which he agrees.
Upon locating Tap, Nick finds a stash of cocaine on his person, allowing them blackmail TAP into leading them to Tyson or risk arrest. Left with no other choice, TAP leads them to an abandoned school. Before they can speak to Tyson, however, Lawrence Kent and his men kill Tyson's associates. Tap flees as the detectives engage in a shootout.
The duo enter the school, only to find Tyson is at another location, and was contacted via video chat. Nick makes an offer to protect him, but Tyson refuses. Khai puts an IP on the lap top, and the duo go to his location. Before Nick can kick the door in Tyson opens it voluntarily. Tyson begins collecting his things when an armed group attacks the residence. Khai is shot in her shoulder possibly hitting an artery, resulting in Nick and Tyson protecting her from countless thugs. The SWAT Team arrives and kills the rest of the criminals and enter, bringing Tyson into custody.
Captain Dawes then sends the two to secure Leo Ray, who has claims to have information about the drug war currently plaguing Miami. Khai and Nick make it to the Elmore Hotel parking garage. Leo, who expected Dawes to meet in person, insults Dao and leaves with the package. Khai attempts to seize the package and is grabbed by one of Leo's men. She takes him down and starts a standoff between the two groups. Remy Neltz's henchman come and attack Ray (for giving information to the police); Mendoza and Dao dispatch all his henchman, and track down Ray's position. Dao reaches Ray first as Mendoza makes his way toward them, subduing Neltz's men along the way. Dao, angry that Ray did not accept the deal with Dawes and tried to betray them, furiously beats him as Mendoza watches in shock.
Mendoza intervenes, and is forced to take Leo's package with Dao holding Leo to safety. The duo load Ray into an SUV; and defeat some of Neltz's men along the way to Dawes's position. Once there, Mendoza covers for Dao to the Captain who asks about Leo's injuries (telling him that Ray was injured in the SUV) so Dao won’t be reprimanded. Seeing through the lie, Dawes asks Mendoza if he will stick to the story or get everyone on the same page, Nick agrees, leaving the interrogation to begin.
Days later, the duo are informed of the information that Leo possessed over drug bales being flown in and dropped into the Florida everglades. The detectives are sent into the glades to find and tag the drug bales with tracers so the drugs can be tracked down later. While there, they cross paths with Neltz's henchman and find clues of the criminal food chain of airplanes bringing in drugs and cocaine.
The detectives also find Leo Ray's severed body in one of the outposts, revealing his capture and subsequent torture after being released from custody. After checking another outpost they find a last generation palm pilot and discover that a meeting is occurring at the old water park stadium. After arriving at the stadium via boat, they proceed to eliminate more henchmen and confront Neltz in a boathouse.
With weapons drawn on him, Neltz, who is standing in a boat, informs them he has taken Stoddard’s deal so everything is ok. Before Mendoza can ask further questions Neltz accelerates the boat and pulls out of the warehouse. Mendoza informs Dao that they will call out the helicopter to track Neltz to his destination.
Dao and Mendoza arrive to Neltz's hideout where Stoddard plans to enter with police forces, but Mendoza (who deems this as his case) enters first with Dao and engage Neltz's remaining thugs in a gun fight. Stoddard (on radio) argues of what they are doing, but the duo neglect his responses as they make it to Neltz. Neltz (with millions of dollars) tells the detectives about the deal with Stoddard, who comes in and kills him via gunshot before he can reveal more. Mendoza, stunned, asks of what's going on as Stoddard takes money from the stash, and gives some to Khai. Nick, who is also given money, realizes the corruption goes beyond Stoddard and drops it on the ground and leaves in disgust.
Betrayed by Corruption
Still disturbed about the last case, Captain Dawes calls Nick into his office where Dao is waiting. Dawes clears the air and informs Nick that it was a test to see if they could trust him and that he passed. Nick, believing Stoddard is a crooked cop, goes back to Neltz's warehouse with Khai under orders from Dawes to find any evidence linking Stoddard and Neltz so they can take it to Internal Affairs and have Stoddard arrested. After returning to Neltz's office Nick discovers a safe hidden behind a painting and unlocks it with his police scanner. Inside he finds a recording of Neltz and Stoddard's deal. Nick returns to Khai who is inside a storage container on the ground level, There the two detectives discover a cartoon character that Neltz had been voicing and track it to a warehouse. They arrive and Mendoza goes into the warehouse as Khai follows a van to the palm court mall where the store is that sells the merchandise related to the character Neltz voiced. Upon entering the warehouse, Mendoza sees Stoddard negotiating with criminals. He sneaks through the building and confronts Stoddard who saves his life as Mendoza tells Stoddard he is under arrest.
Mendoza is contacted by detective Dao who is in trouble at Domo Roboto, the store inside the Palm Court Mall connected to Neltz's business. Mendoza and Stoddard escape the warehouse that has now been set on fire by Neltz men. The two officers then respond to the palm court mall, where they have to deal with some more of Neltz men as a hurricane hits the mall. Mendoza and Stoddard make their way through the mall and rescue Dao from a group attacking the store she is hiding in. The trio escape and defeat more criminals.
After leaving, Stoddard is hand-cuffed by Mendoza as Captain Dawes enters the scene. Nick hands Dawes the recorder and tells him of Stoddard's deal. Dawes congratulates Mendoza on finding the last piece of concrete evidence linking Stoddard to Neltz before dropping the recorder and crushing it under his foot. This reveals that he's the brains behind Stoddard and Neltz deal and that he is corrupt. Before Mendoza can react Dao draws her weapon and holds Nick at gunpoint. Dawes proceeds to tell Nick that all the evidence linking Neltz to a rogue Miami detective is vague and that officers will discover thirty three thousand dollars in his apartment, the exact amount from Neltz last transfer. Angered by their betrayal, Dawes tells Mendoza of being "convinced that he was one of the good guys", but tells him "there's no such thing", Stoddard hand-cuffs Nick who is arrested falsely for being corrupt.
Three years later
After being arrested and framed for Neltz's missing money, Nick is sentenced to 3 years in the Federal Detention Center (FDC) prison. On route to another prison, Nick attempts to stops the harassment of a prisoner and is surprised to see Tap Milstein in the bus. Before Nick can question him however, Tap tells him that something big is about to go down and that Tyson is involved. No sooner than Nick is informed of this, they notice Tyson himself driving up next to the bus holding an explosive charge and nodding to Nick as he throws it on the bus. Tap immediately yells to grab on to something as the bus explodes and injures both men.
Nick awakes and is dragged out of the bus by Tap, who un-cuffs him, ordering him to get to the water tower while he stays behind. Upon arriving, Nick interrogates Tyson, demanding to know why he was broken out of prison and how Tap had gotten onto the prison bus with his cuff keys. Before Nick can question him further, Tyson tells him he needs to speak to the contact, handing him a flashlight and telling him to signal at the nearby billboard, which is quickly returned by the contact. As the two proceeded to make their way toward the contact, they are spotted by a police helicopter, prompting them to split up and meet up at the bill board as they avoid incoming law enforcement.
Upon reaching the rendezvous point, the contact is revealed to be Khai Dao, deeply angering Nick at the sight of his former partner. Khai quickly explains to Nick that they need him to take down Dawes. Tyson explains each of their motives such as Dawes putting him out of business and that much like what he had done to Nick, Dawes finally screwed Khai over. Tyson goes on to explain to Nick that he was the best man to take Dawes down as the hated him the most out of the three of them. Left with the ultimatum of going back to prison or accepting their offer, Nick agrees and goes with them.
Khai and Tyson tell Nick of Dawes' new private security network called Preferred Outcomes, made up of mercenaries and military contractors. Khai sends Nick and Tyson to Dawes' associate, Henry Kang, the major crime lord in Los Angeles. The duo sneak into his car dealership and download files as the alarm is tripped. Kang's men arrive, resulting in a firefight between both sides. Nick and Tyson escape and eventually make it to a nearby junkyard where saves Marcus Boone from a car crusher, and collects Kang's files from Boomer's laptop.
A car chase erupts as the trio are pursued by the remainder of Kang's henchmen in the area which concludes with their successful escape. Boomer then informs Nick and Tyson of how Kang was getting drugs into LA, and tells them his headquarters wasn't far from where they are. Upon arriving Nick kills Henry Kang and his henchman, ending his association with Preferred Outcomes.
The group follow another lead on drug kingpin Neil Roark in Los Angeles. Khai and Nick sneak into Roark's estate and listen into his meeting with Stoddard, who tells his associate's why Kang wasn't there (hiding his death). Nick comes up with an idea to steal Dawes' money before he can launder it and uses Khai's phone as a makeshift tracking device by placing it in a briefcase to be taken to where the rest of Dawes's money is being kept. Roark reveals himself on a monitor asking Nick if he knows who he's stealing from and to be knocked out by Khai sooner after. After surviving a brief assault by Roark's men, Khai and Nick make their escape.
Discovering that Dawes' money is being kept in the penthouse of his corporate HQ skyscraper back in Miami and behind an impregnable vault, Boomer calls a former associate of his for a safecracking robot. Nick and Boomer go to the Mojave Desert and meet their contact, Boomer's ex-girlfriend Dune Alpert who directs them to her father Tony for a meeting which turns out to be a set up. Tony then imprisons Nick and Boomer in an abandoned Cold War bunker.
Dune helps Nick and Boomer escape the compound but are ambushed by Alpert's men at a gas station. The duo hold them off and make it to the abandoned airfield as Dune leaves the desert for good. At the airfield, Boomer repairs a plane as Nick retrieves the robot. Alpert appears in a tank and engages them, prompting Nick to pilot the gun of an old and damaged AC-130 Gunship. Nick kills Tony, emerging victorious and escapes with Boomer in the plane.
Preparing to leave for Miami, the group is ambushed at their hideout by Stoddard. After a brief standoff, Nick kills Stoddard and takes a picture of his body and sends it to Dawes as a warning that he's coming his way. After a successful infiltration of the penthouse, Nick holds off incoming waves of Dawe's men as Tyson unlocks the vault. Believing they have cracked the vault, Tyson enters first, only to discover that its booby trapped and pushes Nick out of the way as hidden explosive detonate. With Tyson gravely injured but alive, Nick finds Khai's phone inside a drawer of the desk with a call from Dawes taunting him to come after him and end it once and for all at his own personal island of Santa Rosita.
Next in Line
— Nick, standing in front of Dawes' fortune.
Upon arriving at the island, Nick tells Khai and Boomer to find Tyson a hospital and that he will take care of Dawes himself. Khai disagrees, however, as she knows Nick is walking into a trap and does not want to leave him alone. Boomer interrupts them, saying that if they take Tyson to a hospital, they'll both be arrested and sent to prison. Nick counters by saying Khai knows black market doctors and that the two of them are the only ones who can ensure Tyson survives his injuries. Khai and Boomer unwillingly agree and depart, allowing Nick to proceed on his infiltration of the estate and make his way toward Dawes. Knowing of his presence on the island, Dawes constantly taunts Nick as he gets closer to his location.
Nick successfully confronts Dawes who tells him that they are the same, saying Nick was now "more criminal than cop" and that he is the most "ruthless son of a bitch" he has ever known. Nick, agrees before killing his former Captain and exacting revenge. Afterwards Nick finds a letter on the desk addressed to him from Dawes detailing his final thoughts and instructions for Nick on how to find his secret vault below the house. Upon opening the vault, Nick finds it filled with Dawes' fortune which now belongs to him. The scene fades to black as Dawes' voice is heard asking Nick what he'll do with it.
Nick was born in Cuba but later immigrated to America at an early age through Miami with his mother. As such he features the typical appearance for someone his age and ethnicity. He has a beauty mark on the left side of his face and stands at 5'11 in (1.80 m) with a slim figure, having black hair and brown eyes.
As a cop Nick wears police gear with a bullet proof vest with casual button down clothing underneath, black pants with his badge at his side. His hair slicked back, combed neatly, and he is clean shaven. During Case Closed, he wears a MPD parka over his regular attire due to the incoming hurricane.
In Episode 5, he no longer is clean shaven nor does he keep his hair slicked back. He also wears a prison suit until he is saved by Tyson and Khai. Afterwards he wears a black leather jacket, the cuffs flipped, a red shirt and blue jeans. During Episode 8, he wears only a button down shirt and blue jeans in the Mojave Desert. In the final two episodes, he changes into a rogue black jumper suit to infiltrate into Preferred Outcomes and Santa Rosita.
— Khai in Episode 1.
Nick's character development in the game focuses on his transition of being an individual who is eventually hardened and numbed to the harsh realities of life. This is conveyed through his status as a cop to being a vigilante and a wanted criminal by the end of the game.
As a young child, Nick was single handedly raised by his mother after relocating to Miami in an effort to escape his father. Dedicated and determined to serve his cause, Nick enjoyed being a cop (or by his terms a "real cop"). Hailing from a family history of criminals and experiencing a traumatic past from his father's domestic abuse, Nick decided to sever ties with his broken past and intended to rebuild his namesake and image. This resulted in him joining the police forces to ensure that justice was rightfully delivered to evildoers, working tirelessly to clean up Miami from the drug war. To many of his partners or leaders, he was often known as "by the book" and "rookie detective" initiative, but was equally respected for his skills on the field. Serving his badge with utter integrity and honesty, Mendoza was incorruptible and true blue detective, as shown when he refuses to take Remy Neltz's money by Stoddard and Khai. 
Prior to his incarceration, Nick was portrayed as an honest, trustworthy, hard-working, bold, eye-catcher, resourceful and effective cop on the force. He was gullible as shown when he was arrested, shocked by Khai's betrayal. He also was known to get frustrated with Khai's impulsive anger and with Stoddard's cockiness, but cares for their safety (until Stoddard was revealed to be a corrupted cop). Despite his field experience, a major setback that would eventually become his downfall was his idealism of being a good cop. For Nick, this meant that joining a lawful entity or organization to serve and protect the civilians. Unfortunately, it resulted in Mendoza being easily manipulated by his coworkers to do their bidding, whilst being kept in the dark of their acts of corruption. He tended to view the world in shades of black-and-white and lacked the political knowledge to realize that corruption exists even in the force of the good. However, it is worth pointing out at some point in the game, Nick was intelligent enough to question Dawes' motives and intention, only to have his suspicions quickly cleared away by Khai (who was then a corrupted cop), Ultimately, this showed that Nick wasn't naive or innocent, but that he was quick to trust and subsequently allowed the words of others to cloud his personal judgment of a given situation.
— Nick to Dawes in Episode 10.
Having being framed by Dawes and Khai for Neltz's missing money on the basis of corruption, Nick was sentenced to 3 year prison term. During the given period, it was implied that he had suffered from a traumatic experience during prison, as he was adamant about not returning to prison again. At the same time, his mother's death during his prison sentence took a toll on Mendoza's personality. His mother's death coupled up with the act of his coworkers of scapegoating him eventually turned him in to a bitter, aggressive individual who had trust issues. He was particularly vengeful against Dawes, who had set him up and ruined his reputation as an officer and tarnished his namesake, which he had worked so diligently to maintain. Especially after being broken out of prison, he became perseverant to Stoddard and Dawes, wanting revenge on the two and pursuing them relentless, as a way for him to seek "justice" and to amend the wrongs. His thirst for vengeance convinced Nick to turn his hatred for Dawes in to a personal matter and subsequently led Nick to being a vigilante in order to serve "justice". Over the course of events that had happened in the game, Nick eventually learns that he didn't have to be a cop to serve justice or clean up Miami. His determination, and final realization that he was more of a criminal than a cop, came to terms and immediate exact of murdering Dawes without hesitation.
His relation with Dawes has a major similarity, the two both change after losing people they cared about, both become more criminals during their change, stealing and killing anyone who stood in their way, but difference is, Dawes was a realist, as Nick was just a victim of being convinced he was one of the good guys.
Nicholas' character development had a few messages that the creators of the game had wanted to deliver to the audiences. Firstly, there is no complete good nor evil, even in the real world. Nick's initial attitude towards his position as a young officer is a reflection of how most people tend to view themselves in actuality - an idealistic individual who attempts to do well and expects everything in society to follow by law when they first set foot in to the modern society. The second message that was intended for the audience was portrayed through Nick's transformation of an gullible cop to a ruthless vigilante, this shows that people eventually realizes that not everything goes by the book (even law) and that dirty tricks are often involved in getting things done from time to time, thereby reiterating the fact that the real world is not black and white, but shades of grey (hovering between what is morally good or wrong, as defined by the individual themselves). Similarly, this was conveyed in Nick's adaptation to the harsh realities of life, realizing that he can no longer be "by the book" in order to serve justice and instead, decides to take actions in to his own hand to deliver his own brand of justice. The third message that was delivered through Nick is the realization of what he had become or transformed in to following his adaptation in to the harsh realities of life, as Dawes had reminded him that he was more of a criminal than a cop.
Relating this into the real world, what it means is that we've all eventually changed and become what we dreaded to be in the first place, we survive in the real world by conforming to the values currently treasured by the society, even if it meant compromising our values and principles and in some cases, committing an act of malevolence in order to survive; in other words, we are no different from the rest. The final message is centered around how we choose to carry ourselves knowing fully well enough that we live in a world full of contradictions, will we carry ourselves in a lawful manner or do we choose to carry ourselves in an evil manner, as reflected in Dawes' final words to Nick, "What will you do?" implying that Nick is free to choose how his fate will end up.
It is worth noting that Nick's stance as a criminal is entirely up to the players to interpret however. Although considered by Dawes to be "more criminal than a cop", it can be interpreted in a way in which Dawes meant using evil to beget evil, thus in that sense, making a Nick "more of a criminal" as he is resorting to unlawful methods to put Dawes' crimes to rest, rather than going through law itself. Since the game ended with a cliffhanger, it is entirely up to the players' imagination to decide if Nick is ultimately lawful good or evil, even after Dawes considers him to be a "realist".
- In the episode Sovereign Land, a character incorrectly refers to Mendoza as Mexican despite the fact that he is Cuban. This is a generalization made by the character, rather than an oversight.
- In Gauntlet, there is a warrant placed on Nick, and when pausing the game, the picture is ripped to fit the level's theme.
- He is clean-shaven until the level Gauntlet, at which point he is seen with scruff.
- Mendoza is from a criminal family, having been stated to be the first legitimately employed member of his family for generations.
- He is the first protagonist in the Battlefield series to speak during gameplay (barring Recker in Battlefield 4 quietly cursing in the beginning of Baku).
- Nicholas' background and story reflects a recurring element commonly employed by most filmmakers in detailing a film about law and corruption.
- As with how Nicholas Mendoza was portrayed, most films often portrays their main character as an earnest individual who is set up or framed for an uncommitted crime, eventually escaping or released from prison and is determined to clear their name by exacting revenge on a particular person. In the process of the story, most of the character usually lose their loved ones and/or being left with nothing. This usually serves as a drive or motivation for many characters to be a changed person and seek out revenge.