Similarities between games

The following is a list of similarities between games in the Metal Gear series. The games often have recurring themes, visual motifs and plot devices.

Codec

 * Codec frequencies. Although slightly obvious, Codec frequencies in each game are sometimes shared among similar characters.
 * 140.85 is used for the lead character's commanding officer (or, in the case of Metal Gear Solid: Portable Ops, his second-in-command). The frequency contacts Big Boss in Metal Gear (where it is 120.85); Roy Campbell in Metal Gear Solid: Portable Ops, Metal Gear 2: Solid Snake, Metal Gear Solid/Metal Gear Solid: The Twin Snakes, Metal Gear Solid 4: Guns of the Patriots, and Super Smash Bros. Brawl; GW impersonating Campbell in Metal Gear Solid 2: Sons of Liberty; Major Zero in Metal Gear Solid 3: Snake Eater. In Metal Gear and Metal Gear Solid 2, this character eventually betrays the main character and feeds him false information or gives him self-destructive instructions. In Super Smash Bros. Brawl, Slippy Toad hijacks Campbell's frequency if the player uses the Codec while fighting Falco.
 * 140.96 is used to record mission data (i.e. save the game). In Metal Gear Solid, the Tanker chapter of Metal Gear Solid 2, and Metal Gear Solid 3, after saving the game, the character who the player contacts via the frequency makes small talk about a certain field of interest. In Metal Gear Solid 3, Portable Ops, and the Tanker chapter of Metal Gear Solid 2, the save game frequency is the secondary Codec frequency of the character who saves the player's game. Mei Ling also uses this frequency to talk to Snake in Super Smash Bros. Brawl.
 * 141.80 is used for someone whom the lead character looks up to as a mentor or idolizes (or vice versa) who often ends up having a secret identity. In Metal Gear 2: Solid Snake, 140.38 is used by Master Miller. In Metal Gear Solid, Master Miller turns out to be Liquid Snake (although it should be noted that Master Miller was killed by the time this revelation was made). In Metal Gear Solid 2: Sons of Liberty, Iriquois Pliskin is Solid Snake in disguise. In Metal Gear Solid 3: Snake Eater, The Boss defects to the Soviet Union. In Metal Gear Solid 4: Guns of the Patriots, Raiden has become a Cyborg Ninja.
 * 140.48 is used by anonymous callers in Metal Gear 2: Solid Snake, Metal Gear Solid and Metal Gear Solid 2; they use pseudonyms on the Codec ("#1 Fan", "Deepthroat", and "Mr. X", respectively). They assist the main character via Codec, even though they work against the main character at times.
 * 140.15 is used to contact a female comrade in Metal Gear 2, Metal Gear Solid, and Metal Gear Solid 4.
 * 141.12 is used by Otacon in Metal Gear Solid, Metal Gear Solid 2, Metal Gear Solid 4, and Super Smash Bros. Brawl.
 * 141.52 is used by a female technical adviser in Metal Gear Solid and Metal Gear Solid 2.
 * 142.52 is used to contact EVA in both Metal Gear Solid 3 and Portable Ops.
 * When the main character is fighting with the final boss, the person usually responsible for giving hints of how to defeat the final boss is unable to help.
 * In Metal Gear, Diane does not know Big Boss's weakness when she contacts Snake.
 * In Metal Gear 2: Solid Snake, George Kasler thinks that Solid Snake may not stand a chance against Big Boss due to rumors about him.
 * In Metal Gear Solid, Naomi is unable to be contacted due to being under arrest for illegally editing FOXDIE, and Roy Campbell is detained by Jim Houseman.
 * In Metal Gear Solid 2: Sons of Liberty, Solid Snake/Iroquois Pliskin is unable to contact Raiden due to being busy chasing Liquid. Although Otacon was left behind and was able to tell Raiden a few hints.
 * In Metal Gear Solid: Peace Walker, Huey Emmerich is at a loss of words on how to advise Snake on how to defeat Peace Walker's second form in the briefing files. During the boss battle against ZEKE, there are no briefing files available on how to defeat it.
 * In Metal Gear: Ghost Babel, the entire support group is held hostage by Brian McBride.

Main Character

 * The lead character being captured, and in some cases, tortured.
 * In Metal Gear, Solid Snake needs to be captured in order to locate Gray Fox.
 * In Metal Gear Solid, Snake is captured by Sniper Wolf and then tortured by Ocelot, who threatens to kill Meryl, who Snake had grown close to.
 * In Metal Gear Solid 2, Raiden is captured by Olga. He's then "tortured" by Solidus Snake in a direct recreation of the torture room from Metal Gear Solid. The capture turns out to be a way for both Raiden and Snake to infiltrate Arsenal Gear.
 * In Metal Gear Solid 3, Naked Snake is captured and tortured by Volgin.
 * In Metal Gear Solid 4, Old Snake is forced to go through a microwave hallway, "torturing" Snake by cooking him alive and occasionally shocking him, and in order to proceed through the hallway, the player must rapidly tap the Action button in a manner nearly identical to the torture scene from Metal Gear Solid , except that they cannot "submit" to the torture.
 * In Metal Gear Solid: Portable Ops, Naked Snake begins the game in a cell and is tortured by Cunningham. He is later captured and tortured again.
 * In Metal Gear Solid: Peace Walker, Naked Snake is captured and tortured by Dr. Strangelove.


 * The main character starts off with one mission, however, his purpose is actually something different.
 * Metal Gear - Big Boss had the rookie Snake sent to Outer Heaven, hoping to have him captured and feed misinformation to authorities, underestimating Snake's ability.
 * Metal Gear 2 - Snake is intially sent to rescue Dr. Marv, but later on in the mission, he has to recover the OILIX formula and destroy Metal Gear D.
 * Metal Gear Solid – Snake is sent under the belief that he is to rescue DARPA Chief Donald Anderson and ArmsTech President Kenneth Baker and determine if the Sons of Big Boss have the capability to launch a nuclear weapon, and if so, stop them, but in actuality it was to infect the Sons of Big Boss, and Baker with FOXDIE so the government can recover the Metal Gear REX without risk of damaging it.
 * Metal Gear Solid 2 – Raiden is sent under the belief that he is to quell a terrorist threat on the Big Shell, but it turns out that he is sent to be the test subject for the S3 Plan.
 * Metal Gear Solid 3 – Naked Snake is dispatched under the premise that he is to rescue Sokolov, and later to assassinate The Boss, Colonel Volgin, and destroy the Shagohod, but in actuality, he ends up helping America to steal the Philosophers' Legacy.
 * Metal Gear Solid: Portable Ops - Big Boss is told that he was to try and recruit the Red Army and disillusioned soldiers to his side in order to clear Para-Medic, Sigint, Major Zero, and his own names of involvement with the FOX revolt, but it is later revealed that he was actually supposed to do this so The Pentagon can tarnish the CIA's reputation by having Gene launch the ICBMG into the Soviet Union.
 * Metal Gear Solid 4 – Snake is used to to infect the remaining founding members of the Patriots (except for Zero) with FOXDIE. Snake also destroys the Patriots' AI and brings back Big Boss, a purpose that had been planned for him since his infiltration at Shadow Moses.


 * Eye patches. In Metal Gear 2, Metal Gear Solid 3, Portable Ops, and artwork for Metal Gear Solid and Metal Gear Solid 4, Big Boss is seen wearing an eye patch (although he also appears in Metal Gear, his eye patch is not clearly visible). In Metal Gear Solid 2, Solidus Snake damages his eye and wears an eye patch, but on a different eye. In Metal Gear Solid 4, Solid Snake is seen using the Solid Eye system which he wears like an eye patch over the same eye Solidus wore his.


 * Solid Snake/Raiden/Big Boss landing in a pose near the beginning of the game while disguised in some way, at which point he raises his head and fully reveals himself to the player. This occurs in the cutscene after the player gets to the elevator at the beginning of Metal Gear Solid and The Twin Snakes, at the start of Metal Gear Solid 2 's Tanker chapter after his stealth camouflage fails and when Raiden take the Strut A elevator up to the roof during his half of the game, at the start of Metal Gear Solid 3 after parachuting into the USSR, and in Metal Gear Solid 4 after losing his militia outfit.
 * Drebin and his pet monkey Little Grey parody this landing pose at one point in Metal Gear Solid 4, shattering the drama by belching loudly after posing.


 * A member of the terrorists (usually the leader) impersonates Snake/Big Boss to damage his reputation.
 * Metal Gear Solid - it was Liquid, who looks identical to Snake anyway.
 * Metal Gear Solid 2 - it was Solidus, who like Liquid, is genetically similar to Snake anyway.
 * Metal Gear Solid: Portable Ops - it was Gene, who managed to frame Big Boss for stealing the ICBMG/RAXA and organizing a rebellion due to Big Boss's reputation.
 * Metal Gear Solid 4 - Laughing Octopus uses her Octocamo to impersonate Snake while attacking the rebels. One of which is released so that he will tell the others not to trust Snake.

Cyborg Ninja

 * The return of a major character from a former game disguised as a ninja. The character's true identity is initially concealed. First used in Metal Gear 2 with Kyle Schneider, then Metal Gear Solid with Gray Fox and finally in Metal Gear Solid 4 with Raiden. After appearing as herself in the Tanker chapter of Metal Gear Solid 2, Olga Gurlukovich reappears as a ninja in the Plant chapter.


 * A Cyborg Ninja telling the main character to hurry after saving them. Gray Fox says "Hurry, get away!" after saving Snake from REX, Olga says the same thing after saving Raiden. In Metal Gear Solid 4, Raiden says "Hurry!" to Snake after stopping Outer Haven from crushing him.


 * A unit fights the ninja in an enclosed space. In Metal Gear Solid, Gray Fox uses his Stealth camo to surprise a unit of Genome soldiers. In Metal Gear Solid 2, Vamp slaughters a SEAL Team (while Vamp is not a Cyborg Ninja, this scene is meant to replicate what Gray Fox did in Metal Gear Solid) Olga takes on Ocelot and the soldiers in the hall with the hostages. In Metal Gear Solid 4, Raiden intervenes in Snake's fight against the FROGS.

Other Characters

 * A scientist that the main character must rescue: Dr. Drago Pettrovich Madnar (Metal Gear and Metal Gear 2), Dr. Kio Marv (Metal Gear 2), Otacon (Metal Gear Solid), Emma Emmerich (Metal Gear Solid 2), Sokolov (Metal Gear Solid 3), and Naomi Hunter (Metal Gear Solid 4).


 * A scientist that at some point loses bladder control out of fear: Otacon (Metal Gear Solid), Emma (Metal Gear Solid 2), and Sokolov (Metal Gear Solid 3).
 * Some of Snake's teammates are passionate about their hobbies: Otacon (Metal Gear Solid) is a fan of anime, Mei Ling (Metal Gear Solid) is a fan of classical literature and Para-Medic (Metal Gear Solid 3) is a fan of movies. Sometimes, they will reference something from their hobby as advice to the player: Mei Ling will cite proverbs and Para-Medic will try to relate Snake's situation with a movie she saw.


 * Johnny Sasaki and his bowel problems. Metal Gear Solid, Metal Gear Solid 2, Metal Gear Solid 3, Metal Gear Solid 4. Metal Gear Solid 3 's Johnny is the grandfather of the Johnny from the rest of the series.


 * Some one Otacon cares for/loves dies. Sniper Wolf in Metal Gear Solid, Emma in Metal Gear Solid 2, and Naomi in Metal Gear Solid 4.

Quotes

 * The use of the line "It's not over yet." Originally said by Big Boss in Metal Gear 2, this was later said by Liquid Snake in Metal Gear Solid, Olga in Metal Gear Solid 2, Volgin in Metal Gear Solid 3, and Sokolov in Metal Gear Solid: Portable Ops. In Metal Gear Solid 4, Liquid Ocelot uses a variation of the quote in Act 4 in Shadow Moses "It's not over! Not yet!" when he arrives in Metal Gear RAY, and gives the exact quote if, when Snake dies in the microwave hallway, the player chooses "exist". Liquid also uses this line Metal Gear Online if he is on the losing team and is killed just before the end of the match, right before rising again and extending the match for another forty seconds. If one of the Custom AI Weapons manages to reboot itself after having its health depleted, it will also say "It's not over yet."


 * In Metal Gear Solid 2 and Metal Gear Solid 3, there is a line of dialog at the beginning of each game where Snake says "Kept you waiting, huh?" This very sneakily breaks the fourth wall. The line is not used in-game in Metal Gear Solid 4, but Snake does say after the initial 8-minute installation when the game is loaded for the very first time. Also, in Super Smash Bros. Brawl, Solid Snake says the line at the beginning of every match, and in a trailer. During the Subspace Emissary there is a cut scene fairly early on of Snake's Box. Much later in the game Snake is seen emerging from the box, where he then turns to the camera and says "Kept you waiting, huh?" It is also said in the Snake Tales story External Gazer by an alternate universe version of Solidus Snake, when he says to Mei Ling "Kept you waiting, huh?" One of the CO-OPs messages in Peace Walker is "Kept you waiting, huh?"


 * The use of the line "neither enemy, nor friend." This was said by Gray Fox in Metal Gear Solid, Olga as Mr. X in Metal Gear Solid 2, Drebin in Metal Gear Solid 4 and by Kazuhira Miller in Metal Gear Solid: Peace Walker during his phone call to Zero (in this case, he elaborates that he is a business partner.).


 * In Metal Gear Solid/The Twin Snakes and Metal Gear Solid 3, both Snakes are tortured and ask a support member to tell them a story to take their minds off the pain they feel at the time.


 * In Metal Gear Solid, Ocelot tells Solid Snake "You're pretty good" after being defeated. In Metal Gear Solid 3, Naked Snake says this when he first defeats Ocelot. Liquid Ocelot says this when he's beaten by Old Snake in Metal Gear Solid 4, which were also Ocelot's last words before his death from FOXDIE.
 * In Metal Gear Solid 2 and Metal Gear Solid 3, someone says the line "There's room for only one Snake and one (Big) Boss." This was said by Liquid Snake upon his departure in Metal Gear Solid 2, and by The Boss upon her death in Metal Gear Solid 3.

Games

 * A scene that demonstrates the boss characters superiority to Snake. Typically they do this by obliterating a unit of soldiers while Snake watches from the shadows.


 * Battles with an aircraft. In Metal Gear, Metal Gear 2 and Metal Gear Solid they were Hind D choppers. In Metal Gear Solid 2 it was a Harrier II jump jet. In the original Metal Gear, Solid Snake destroys the Hind D with a grenade launcher before it could launch. In the latter three games, the protagonist (Solid Snake in Metal Gear 2 and Metal Gear Solid; Raiden in Metal Gear Solid 2) attacks the flying aircraft with stinger missiles. Naked Snake can evade or destroy Hind A choppers in Metal Gear Solid 3, but these are not mandatory boss battles as they were in previous games. Also, Big Boss has to fight off against a flying platform piloted by Cunningham in Portable Ops. In Metal Gear Solid: Peace Walker, Big Boss must neutralize an MI24A chopper.


 * After the end credits there will be a talking sequence where a major plot twist is revealed. In Metal Gear, Big Boss reveals that he survived. In Metal Gear 2, there is a conversion between Solid Snake, Roy Campbell and Holly White. In Metal Gear Solid, Metal Gear Solid 3, and Metal Gear Solid: Portable Ops, the character doing all of the talking is Ocelot. While in Metal Gear Solid 2 and Metal Gear Solid 4, there is a conversion between Solid Snake and Otacon. In Metal Gear Solid: Peace Walker, Naked Snake states to Miller that he is now going to be called henceforth as Big Boss and not Snake, and after the second ending credits, Big Boss announces the creation of his military nation Outer Heaven.


 * Sea insertion is the primary method of infiltration into the enemy stronghold in Metal Gear, Metal Gear Solid, and the Plant chapter of Metal Gear Solid 2.
 * Also, a HALO/HAHO jump was also the primary method of infiltration into the enemy region in Metal Gear 2, Metal Gear: Ghost Babel and Metal Gear Solid 3.


 * A one-on-one fight without any firearms between the protagonist and one of the final bosses in Metal Gear 2, Metal Gear Solid, Metal Gear Solid 2, and Metal Gear Solid 4.


 * A final boss battle where there is a time limit caused by a bombing raid. In Metal Gear Solid, B-2 bombers are sent to destroy Shadow Moses while Solid Snake fights Liquid. In Metal Gear Solid 3, MIGs are sent to bomb the field where Naked Snake and The Boss fight. Although not a boss battle, in Metal Gear Solid 4, Snake has to escape on Metal Gear REX with 5 minutes before the Gekko explode.


 * In one of the final boss battles, there is the added tension that another character may have died or may die as a consequence of the battle. In Metal Gear 2, Solid Snake is forced to fight and kill his former friend and mentor, Gray Fox. In Metal Gear Solid, Meryl will die if Snakes give in to torture (as well as having a dilemna when Snake either allows REX to survive in order to allow Gray Fox to live, or use the newly obtained opportunity to fire the stinger missile into the cockpit of REX, but at the same time, kill Gray Fox in the process). In Metal Gear Solid 2, Sunny will be killed by The Patriots if Raiden fails. In Metal Gear Solid 3, killing The Boss is Snake's mission even though he doesn't want to kill her.


 * A battle against multiple Metal Gear units where the protagonist is armed with only one suitable weapon. In Metal Gear Solid 2, Raiden fights off RAY units using a Stinger missile launcher. In Metal Gear Solid 4, Snake has to fight off waves of Suicide Gekko with the railgun.


 * The final mission is practically a suicide mission. In Metal Gear Solid 2, Snake and Raiden have to defeat all the Tengu Commandos and RAY units on Arsenal Gear. In Metal Gear Solid 4, Snake has to infiltrate the ship Outer Haven which is guarded by FROGS and Gekko. He also has to go through a microwave filled hallway.


 * Often the antagonist is trying to create Outer Heaven, a nation of soldiers, in Metal Gear, Metal Gear 2, Metal Gear Solid and Metal Gear Solid 4. The precursor to it was Army's Heaven in Portable Ops.


 * Often data is stolen allowing the Metal Gear threat to continue even though the current version will be destroyed.
 * Metal Gear Solid - Ocelot steals the Metal Gear REX data and sells it on the black market.
 * Metal Gear Solid 2 - Ocelot's aim in the Tanker chapter is to steal RAY before destroying the tanker itself.
 * Metal Gear Solid 3 - Ocelot stole the Metal Gear plans from Granin, EVA stole the Shagohod data and the Philosophers' Legacy was also stolen
 * Metal Gear Solid: Portable Ops - Ocelot stole the Trajectory Data from the DCI, which contained the Philosophers' Legacy.


 * The main character has a relationship or a connection to the final boss.
 * Metal Gear and Metal Gear 2: Solid Snake - Big Boss.
 * Metal Gear Solid: Solid Snake - Liquid Snake.
 * Metal Gear Solid 2: Raiden - Solidus Snake.
 * Metal Gear Solid 3: Naked Snake (Big Boss) - The Boss.
 * Metal Gear Solid 4: Old Snake - Liquid Ocelot.

Metal Gear Solid 2: Sons of Liberty

 * Someone who is rescued asks to help but gets denied as they would just slow them down. However, they prove to have more mobility than they seem to.
 * In Metal Gear Solid, Otacon has stealth camoflage and provides snake with rations and ammo.
 * In Metal Gear Solid 2, Peter Stillman reveals that he doesn't really have a prosthetic leg and helps defuse the bombs.
 * The protagonist is given fake data to prevent the real data being stolen.
 * In Metal Gear Solid 2, Solid Snake gives Raiden a fake virus, which Ocelot later steals from him. The real virus was supposed to contain the names of the Patriots.
 * In Metal Gear Solid 3, The Boss or Ocelot planted a fake microfilm on EVA, which she believed to contain the records for the Philosophers' Legacy.

Metal Gear Solid: Portable Ops
Portable Ops contains some references to other games in the series.
 * The relationship between Big Boss and Gene is similar to the one between Solid Snake and Liquid Snake. Gene is the end result of the Successor Project, a project designed to infuse a soldier with The Boss' genes (also a precursor to the Genome Soldier project). Gene even goes so far as to call Big Boss "brother."
 * One of Gene's telepathic quotes during his and Big Boss's climatic battle was almost an exact quote to The Boss's speech during their first encounter in Operation Snake Eater.
 * In Metal Gear Solid, Solid Snake has to take down his former unit, FOXHOUND. In Portable Ops, Naked Snake has to take down his former unit, FOX.
 * Both Portable Ops and Metal Gear Solid feature Frank Jaeger as a ninja who has been experimented on by the enemy's unit as part of a secret project. In both games, Frank is partly insane and determined to kill the player character until he comes to his senses near the end.
 * In Metal Gear Solid 3 there is a backwards interrogation where Volgin reveals information about the Legacy that Snake did not know. In Portable Ops, Cunningham unintentionally implied that he is actually working for the Pentagon while threatening Snake and his men.
 * The music in general is similar to music from Metal Gear Solid 3, and two specific songs are remakes of songs from Metal Gear Solid 2. The track "Sad Man's Theme" is a remake of "Peter's Theme" and "Evasion" is a remake of "Countdown to Disaster."
 * Big Boss' last action in this game is to salute his comrades. This is similar to his last action in Metal Gear Solid 3 and Metal Gear Solid 4, where he salutes The Boss' grave.

Metal Gear Solid 4: Guns of the Patriots

 * The scene in Act 1 where Snake tries to kill Liquid is similar to their meeting in the Tanker in Metal Gear Solid 2.
 * Snake has to sneak past a large group of soldiers.
 * He hides behind some boxes where he can see Liquid who is in an elevated position.
 * Liquid steals a piece of technology and as a consequence of this Snake and the soldiers are put at risk.
 * Once Snake reveals himself, Liquid makes a speech.
 * Liquid uses a vehicle to escape.
 * Someone comes in and saves Snake from the situation.

Metal Gear Solid: Peace Walker

 * The plan for Big Boss's mission in Costa Rica is similar to Raiden's participation in the Big Shell Incident. Both were ostensibly to remove a threat (the Sons of Liberty in Metal Gear Solid 2, and the Peace Sentinels in Peace Walker), both had initial hints of the true purpose being to mold them into a new legendary hero [Solid Snake for Raiden, and Che Guevara for Big Boss], but were actually intended to achieve far more sinister purposes [testing out AI machines to consider dominion over humanity as well as to sway Big Boss back to The Patriots or frame him if all else fails, and testing whether the Patriots could control human society]).
 * The Militaires Sans Frontiere's main base, the Mother Base, bears a strong resemblance to the Big Shell.
 * Similar to Metal Gear Solid 2, the apparent main instigator of the event is also a disgraced member of the government because of his involvement in a mission (in Metal Gear Solid 2, this was Solidus Snake, a.k.a. George Sears, the former President of the United States who resigned due to it becoming public knowledge that he was involved in the Shadow Moses Incident, and in Peace Walker, this was Hot Coldman, the former CIA Director who was removed from this position and exiled in the guise of becoming the Station Chief of Central America's CIA branch for his involvement in the Virtuous Mission and Operation Snake Eater).
 * In both Metal Gear Solid 2 and Peace Walker, an agent of the Patriots mentions taking a Metal Gear back while hijacking it (Ocelot told Scott Dolph, and shortly thereafter Sergei Gurlukovich, that he intends to "Take [RAY] back [to the Patriots]" and Paz Ortega Andrade tells Big Boss that she's taking Metal Gear Zeke back). Coincidentally, both Metal Gears had their codenames derived from a codename for the Japanese Mitsubishi A6M Zero line of fighters.