Throughout the Metal Gear series, there are scenes that appear after the credits have rolled and usually reveal a plot twist.
This scene is not featured in the Nintendo Entertainment System version.
Metal Gear 2: Solid Snake
Solid Snake, Colonel Roy Campbell, and Holly White are debriefed about the Zanzibar Land Disturbance, with Snake refusing to rejoin FOXHOUND due to him having been cured of his nightmares. He later tells them they don't need to run testing as the cartridge he retrieved was the right one. Snake then plays it on an MSX console, and Campbell confirms that he was right. When Holly still expressed confusion over the matter, Snake explains to her that they were able to confirm it was Dr. Kio Marv's cartridge due to his signature being backwards: VRAM 01K. After a brief discussion about how Dr. Marv was ultimately a victim of a political game, Snake inexplicably disappears from the scene, much to Holly's chagrin.
Metal Gear Solid/The Twin Snakes
Revolver Ocelot makes a phone call to the President, and confirms that he succeeded in his mission to retrieve the Metal Gear REX data, and with the exception of Donald Anderson, whom he deliberately killed while making it look like an accident, no one suspected his true allegiance. He also verifies that the FOXDIE virus is set to act within Solid Snake. Depending on the ending in the original version, he'll also reveal that Liquid Snake had been misled into believing he had been the inferior clone, and that the President himself is actually a product of the Les Enfants Terribles project with the codename of Solidus. Finally, he confirms that they put a woman under surveillance.
This is the first game where the title appears during the conversation. Later games would use the game's logo during this sequence. In the original game, Liquid Snake being the actual superior clone, the revelation that the President was a LET clone, and a woman being placed under surveillance is only in the Meryl Lives ending. In The Twin Snakes, this is included in both endings.
Metal Gear Solid 2: Sons of Liberty
Otacon calls in and informs Snake that he has successfully analyzed the data they had retrieved from Arsenal Gear, and revealed that one of the names of the Wisemen's Committee had in fact been one of their biggest contributors. However, he then tells Snake that, while he did confirm that the Wisemen's Committee had in fact been based in Manhattan, all of its founding members had in fact been dead for at least a century, with Snake expressing shock and confusion.
Although technically not a post-credits scene, something similar was depicted in the trial demo, which after getting to a certain point (either defeating Olga or entering the boiler room, depending on the demo version used), it will show the Metal Gear Solid 2 logo, as well as have some dialogue that would occur later on, specifically Otacon admitted that he had help locating Metal Gear RAY, Ocelot's betrayal of Sergei Gurlukovich, Liquid's return, and Snake apparently meeting a bad end.
Metal Gear Solid 3: Snake Eater
Ocelot debriefs his KGB boss on the result of the mission, confirming the destruction of both Groznyj Grad and the Granin Research Facility. He also informs his boss that the losses were necessary, as well as confirming the CIA had taken care of The Boss as agreed. He states that Nikita Khrushchev is finished and his boss' time has finally arrived. Ocelot suggests that they use their knowledge of the operation and President Lyndon B. Johnson's expectations that they keep a lid on the affair as blackmail for future negotiations with the U.S., before confirming that he'll keep the KGB informed.
After hanging up, he then makes an outbound call to the CIA Director, revealing that he is in fact a CIA agent as well. He also reveals that The Boss completed their mission and that the Philosophers' Legacy is in America's hands, verifying that the microfilm that a Chinese agent stole was a fake. However, he confirms that the Philosophers' Legacy was only half of the total amount, with Ocelot suspecting the KGB had the other half. He also verifies that the Shagohod was destroyed, and that Groznyj Grad had been obliterated by The Boss via the other Davy Crockett they had brought in. He also revealed that he had intercepted the blueprints for a new weapon by Aleksandr Leonovitch Granin and was sending them to the CIA for a potential weapon for America, and inferred that Big Boss may have been partly responsible for it (also letting slip he knew him as John). He confirms that Khrushchev believed their cover story and that the second alert is rescinding on the Soviet's end, and that the Soviets neither realize he was triple-crossing them nor do they even know his true identity. Finally, he verifies that no one knows that he was ADAM, and confirmed that he'll still act as an agent for the new government, and that in the meantime, he'll be at the CIA's disposal.
Unlike prior entries, the end screen shortly after Ocelot hung up changes slightly, where the colors invert (ie, the text goes black while the background turns white). Something similar would occur with Metal Gear Solid: Peace Walker.
Metal Gear Solid: Portable Ops
Ocelot receives a call from his employer, with him being surprised at the identity of the employer. He then confirms that he killed the CIA Director and made sure that it passed as a suicide, and implied that the CIA will have a major shakeup on their hands as a result. He then verified that he also collected the full Legacy, and that thanks to his employer's leaking of the ballistic trajectory data to the director implicating him as the target, he went directly into his trap. He also confirmed that Gene's actually launching the nuke had not been part of their plans, and revealed that Snake had been their insurance policy. Ocelot also accused his employer of using him, and cited that he'll no longer serve him. However, after his employer revealed that he had battle data from the Perfect Soldier Project and implied that it involved soldier genes and genomes, Ocelot admitted that he could aid him in his project, although only under the condition that Big Boss join up so they could form the Patriots.
Metal Gear Solid 4: Guns of the Patriots
Otacon tries to hand over cigarettes to Snake, as he had merely forgotten them. However, Snake decides to quit smoking. Snake then mentioned that he was going to make sure he sees the new world he had in effect created with the little amount of time he has left in life. Otacon then requested that he join him, largely so he could witness Snake's last days, although he also admitted that he also didn't want to eat Sunny's prepared meals alone. Sunny then requested that everyone come and see the eggs she had created.
Originally, she was specifically addressing Otacon and Snake to see the eggs, but Hideo Kojima had it changed so it would be ambiguous as to who she was referring to. The change was last minute, as it used the cinematics from the original line.
Metal Gear Solid: Peace Walker
The game features two post-credit conversations, the first after the fourth chapter, and the second after the fifth.
In the first ending, Kazuhira Miller arrives at Big Boss's location and tries to get him to return (implying that he had stayed at Lake Nicaragua for a long time), citing that everyone was waiting for him. Big Boss then stated that he wasn't coming back, and cited that The Boss betrayed him with her final message, as she instructed him never to put his gun down. He then said he was following a different path, and eventually said he will be addressed as Big Boss from that point onward.
In the second ending, Big Boss gives a speech in front of various MSF-soldiers, informing them that they may have to undergo various dirty jobs, even support terrorism, and their actions may lead to them going to hell when they die, before formally renaming the Militaires Sans Frontières as Outer Heaven.
Similar to in Snake Eater, after the post-credit scenes dialogue conclude, the screen will be altered slightly, with the text turning from white to black, although the color of the background's change will vary depending on whether it was the first or second post-credits scene. If the former, the black background will turn yellow. If the latter, it will turn to red.
Metal Gear Rising: Revengeance
Boris Vyacheslavovich Popov contacts Raiden, and confirms that thanks to Raiden's actions and Steven Armstrong's death, World Marshal was put to sale and the Sears Program was eliminated, although World Marshal itself was still in function, especially with the re-emergence of the war economy. Raiden briefly recalled Armstrong's final words to him. Raiden also confirmed that he won't be returning to Maverick, and then cited that he has his own war to fight.
Halfway through, it shows Raiden, in a human-like body similar to his appearance in the opening, walking through a town, with four cyborg soldiers lying in wait to ambush him. As they ready to attack him, Raiden then materializes a container that is implied to contain his sword, and gives a brief smirk as his eyes shine red before the Metal Gear Rising logo appears.
Metal Gear Solid V
Metal Gear Solid V: Ground Zeroes
Skull Face informs Paz Ortega Andrade that, thanks to the failure of his grand experiment, Zero had gone into hiding, with various Cipher agents getting their orders only from proxies, before pointing out that Paz was the exception to the rule as she actually met him in order to meet up with Snake, and thus she knew Zero's location. He then demanded that she tell him his location before telling her that he never knew freedom, and Paz was effectively free. She then asked if this knowledge would aid Big Boss and whether he would kill Zero for her. Although Skull Face inferred that it might help Big Boss survive, he made clear that he won't kill Zero, not for her sake at least. Paz then proceeds to tell him Zero's location after some hesitation. Although technically during the credits rather than after them, the very beginning of the credits has Skull Face sarcastically saying that "Here's to You" was Paz's favorite song, and described the song's message, before telling Paz that her sacrifice won't change things.
This conversation, as well Skull Face's comment about "Here's to You", both can actually be found on Chico's sixth tape.
Besides the main story, there are also post-credits debriefings for all of the side missions except for the Intel Operative Rescue mission. Two of the side missions (three counting extra ops) also include two alternate debriefings, depending on the player's actions for the mission:
In Eliminate the Renegade Threat, depending on the manner in which the player deals with Glaz and Palitz, the debriefing is different. If the player kills them, Miller will cite that the war will be over soon with their deaths, although he then noted that Glaz and Palitz carrying a huge amount of fear, deep enough that even death didn't terrify them, causing Miller to question what was going on at the Naval facility. If the player non-lethally extracts them instead, Miller will reveal that they had searched Glaz and Palitz upon their arrival and discovered that they had a prosthetic finger and a glass eye, indicating that they had resorted to self-mutilation after drugs and therapy couldn't help them from their memories, with Miller reflecting that they had been human after all.
In Classified Intel Acquisition, if the player recovered the tape from the watchtower only, Miller will call in and reveal that the tape contained an interrogation, which served as proof that it had been converted to a black site, although he then told Big Boss that the tape they recovered was also supposed to have a full detailed account of the plan, causing him to wonder if they missed a tape. If the player either recovered both tapes or the tape from the bald soldier only, Miller will confirm from the tape that the base's "expansion of refugee camps" had been a lie, and that they were planning to house more prisoners, and uncovered that they had even purchased several transports intended to abduct even civilians, with him wondering if this is what Cipher's "world without borders" was going to be about.
In Destroy the Anti-Air Emplacements, Miller will confirm that the base was wiped out, along with any witnesses to the base. He also said that who hired the bombing run isn't confirmed, although the design of the aircraft made clear that the aircraft were of western origin. Miller also mentioned that the authorization of the black site had come from the top, and also implied his suspicions that Cipher had been responsible for the air raid.
In Jamais Vu, Miller commented that they still don't know exactly what the Body-Snatchers were, although they were hopeful they didn't have anything bigger planned, and remarked it was all like a bad dream.
In Déjà Vu, like in Eliminate the Renegade Threat and Classified Intel Acquisition above, there are two different post-credits scenes depending on how the player completes the mission. If the player doesn't get all seven recreated scenes, Miller will call an unknown contact about how Big Boss managed to complete the mission, only to learn he hadn't found all the scenes in a manner similar to the post-credits scene for MGS1. If the player manages to recreate every scene and pass the quiz, Miller, while posing as Ocelot, will state that Big Boss lives up to the legend, tells him that he is pretty good, and that matches up with the code of the boss (alluding to what Ocelot says if the player does well against him in their boss fight). On a related note, Miller, while posing as and quoting various characters, has the player undergo a quiz relating to the original Metal Gear Solid if the player manages to recreate every scene.
The Phantom Pain
Upon completing the Truth mission, Miller will express shock about learning that Venom Snake was not actually Big Boss, and wonder what they were even fighting for. Ocelot (who presumably told him the truth) then reveals that the real Big Boss was finding Outer Heaven in South Africa. Miller then expresses despair, realizing that he hadn't actually lost everything in the attack, but from learning about Big Boss leaving them. Ocelot then revealed that both Venom Snake and Big Boss will be making a two pronged attack on Cipher and undergoing a new revolution. However, Miller then bitterly states that he'll make Venom Snake stronger as well as train the sons to ensure Big Boss is sent to hell. Ocelot then mentions there can only be one Big Boss, and also warns him that when the time comes and he sides with one of the sons, Ocelot will side with the other, and they will have to kill each other. Miller is content with the idea, and departs, although not before bitterly telling Ocelot that they'd better get used to coexistence before then.
After the credits roll for Chapter 1: Revenge, it shows Eli meeting with Tretij Rebenok and receiving the last remaining English vocal cord parasite sample. Although technically not a post-credits scene per-se, a trailer is also shown for Chapter 2: Race after the credits rolled. It depicts several things, such as the outbreak, Quiet's sacrifice, Eli's treachery, Huey's trial, and Venom Snake discovering the truth of who he is.
In addition, because of the more episodic method of storytelling of each mission, some of the missions feature post-credit scenes that, similar to the Side Ops and Extra Ops from Ground Zeroes, will feature Miller giving a debriefing to the player on the mission, with some either being made available by completing certain objectives, or otherwise expanding on the debriefing depending on how the player completes the mission.