Before filming began, the cast underwent training from real Navy SEALs. They were then brought to the set for a mock battle in full uniform and weapons (loaded with blank ammunition), in which the SEALs played the role of the Taliban. Taylor Kitsch was the best prepared of the cast, as he had previously received physical and technical training from Navy SEALs for his previous two films Battleship (2012) and Savages (2012).
Was made relatively cheaply by writer/director Peter Berg, who labored to make it happen over five years. Involved only a 42-day shoot and $40-million budget. Stars Taylor Kitsch and Mark Wahlberg worked at a discount, as did Berg, for the mandatory Directors Guild minimum salary of $17,000 a week.
The tumbling and falling scenes were filmed on location without CGI enhancement, and necessitated that the stunt performers subject themselves to genuinely hard falls. After one such stunt, Mark Wahlberg's stunt double had to be hospitalized.
Mark Wahlberg later admitted that the shoot was the most physically demanding of his career, as he was in a great deal of physical pain while filming, with three herniated disks, labrum tears in his shoulders and a shattered knuckle. However, due to the presence of Marcus Luttrell and other Navy SEALs on-set, he never complained.
Mark Wahlberg claimed that the real Marcus Luttrell was initially very guarded with him when they first met, and would not make eye-contact during conversation. Wahlberg earned his trust over the course of weeks, before Luttrell was willing to speak candidly.
Gregory Rockwood was one of the crew members awarded the 2004 Mackay Trophy for the "most meritorious flight of the year" by an Air Force person, persons or organization. Jolly 11 and Jolly 12 crew members distinguished themselves by gallantry in connection with rescue operations near Kharbut, Iraq, on 16 April 2004. While supporting of Operation Iraqi Freedom, Jolly 11 Flight launched to rescue a five-person crew of a U.S. Army CH-47 Chinook helicopter that crashed in a sandstorm with near zero-visibility. En route to the crash scene, crews realized their forward looking infra-red and night vision goggles were ineffective. Despite this handicap the crew of Jolly 11 was able to locate the survivors. Both aircraft then made near -ero-visibility approaches relying nearly exclusively on the flight engineers' and aerial gunners' inputs for precision navigation. Following the successful survivor contacts and recovery by the Flight's Pararescuemen, Jolly 11 and Jolly 12 were individually engaged by separate multiple surface-to-air missiles attacks. Using evasive maneuvers Jolly 11 evaded two missiles. Both Jolly 11 and Jolly 12 continued to provide support with defensive fire until the formation was clear of the threat area, saving the lives of five U.S. Army personnel.
Despite Marcus Luttrell's Texan heritage being specified in the film, the real Luttrell advised Mark Wahlberg that he would never be able to imitate a Texas accent, and to not bother imitating his voice.
At the end of Battleship (2012), Taylor Kitsch's character is challenged by a Navy SEAL to come down to Coronado and enter training to become a SEAL himself. Kitsch played Navy SEAL Lt. Michael Murphy in this film.
The trivia items below may give away important plot points.
Before filming began, director Peter Berg visited the families of the dead. The father of Danny Dietz, played by Emile Hirsch, read him an autopsy report detailing the 11 bullets that tore through his son. "He was reading that and crying," says Berg, "and then he said, 'That's who my son was. That's how hard he fought. Make sure you get that right.'"
Despite what the film shows, with Marcus walking around with a limp leg, in real life Marcus Luttrell was paralyzed from the chest down during the battle and was crawling across the ground, drawing a line above him with a knife then crawling across that line and drawing another, for over nine hours.
Though it is not mentioned in the movie, Marcus Luttrell was personally awarded the Navy Cross by then-President George W. Bush. Lt. Michael Murphy would be awarded the Medal of Honor posthumously. Axelson and Dietz were also awarded the Navy Cross posthumously.
Marcus Luttrell makes a recurring cameo as an unidentified Navy SEAL. He makes his final appearance on-board the doomed rescue helicopter. Luttrell said it was very cathartic to portray one of the men who died trying to save him.
To get a genuinely surprised reaction when a mortar explodes behind Marcus after he asks Gulab, "Why are you doing this for me?", Peter Berg ordered the explosion detonated on the count of 2 instead of 3. An unprepared Mark Wahlberg got hit by debris in his face and angrily stormed off set. Berg waited outside Wahlberg's trailer for an hour to apologize, after which Wahlberg returned to finish the scene.
The real Marcus Luttrell described Mike Murphy's death as even more harrowing than what is shown in the film: the mortally wounded Murphy died screaming Luttrell's name, which shook Luttrell, unable to help due to the shower of surrounding gunfire, to the point of dropping his rifle in order to cover his ears; unable to listen to his friend die.
The film deviates from Marcus Luttrell's account of the decision to release the goatherders. In his book of the same name, Luttrell describes Lt. Murphy favoring release of the prisoners but placing the decision up to a vote, with himself and Murphy favoring release, Axelson in favor of killing the prisoners and Dietz abstaining. Luttrell's account was controversial, as military procedure requires the officer in charge to give legal orders, and Murphy's father objected to the notion that his son would abdicate his responsibility. In the film, the mens' respective opinions are reflected according to Luttrell's version of events, but Murphy is depicted as decidedly telling the others "This is not a vote" before giving the order to release the prisoners.
In real-life Mike Murphy and Matt Axelson were college graduates, both with degrees in political science, whose decision to join the military came as a surprise to those who knew them. At the time of his death Axleson was due to return home in four months, at which time he planned to settle down in a new home with his wife.
In the scene right before Shane Patton does his dance, a patch can be seen with Marc Lee's name. Marc Lee served with Chris Kyle and would later be killed in action, as depicted in Kyle's book and movie titled "American Sniper". Marc Lee was also the first SEAL killed in operation Iraqi/Enduring Freedom.