History TheDevTeamThinksOfEverything / MetalGear

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[[AC:''Metal Gear Solid'' / ''Twin Snakes'']]
* Psycho Mantis can read ''the player's'' mind by reading memory card data, providing a detailed analysis of the player's proficiency at the game (how good they are at stealth and combat, and how frequently they've saved their game), and suggesting that the player enjoys certain games like, say, ''VideoGame/{{Suikoden}}'' or ''[[VideoGame/CastlevaniaSymphonyOfTheNight Castlevania]]'', [[WebAnimation/AwesomeSeries for instance,]] or ''VideoGame/SuperMarioSunshine'' and ''[[VideoGame/SuperSmashBros Super Smash Bros. Melee]]'' in the UsefulNotes/NintendoGameCube remake. Even better, in the Japanese version, having save data from both VisualNovel/{{Snatcher}} and VisualNovel/{{Policenauts}} unlocks a special message from HideoKojima. If for whatever reason you're unable to use the second controller port, Colonel Campbell will eventually reveal an alternate way to beat Mantis: destroying the busts in the room.
* One of the most famous things in the original ''MGS'' was the box warp. By climbing onto a supplies vehicle and equipping a box from elsewhere in the game, you could be transported to that location.
* Because there's only water at the very beginning of the game, in one ''very'' small and specific place, and where there is literally ''no'' reason to backtrack all the way there once you've found a gas mask, you'd expect the developers to have taken the easy way out and coded the gas mask to simply "slow the OxygenMeter". Nope; try it and it has no effect underwater.

[[AC:[=MGS=]2]]
* If you enter the only place with a mirror on the Big Shell and equip either the Camera or Sniper Rifle (weapons that force you into first person mode and which you won't have the first time you visit), you see that Raiden is properly rendered holding either.
* Shooting the mirror causes it to splinter realistically, and pieces will scatter across the floor. Raiden can still be seen in the shattered reflection. Speaking of that washroom, urinals, hand driers and sinks all work if you get close enough to them.
* There's a point in the game where Raiden is discovered regardless of how good you are, and the whole facility goes onto high alert. If you return (with no purpose in the storyline) to some of the earlier parts of the facility at this point, there are more guards. This is also the only way to get some of the dog tags.
* Speaking of the uniform, you'll notice it's still in your inventory despite being useless now that it's lost the balaclava. Turns out it's not completely useless: if you wear the uniform in an area where you'll leave footprints, the guards will ignore them rather than follow because they match those of their own boots.

[[AC:[=MGS3=]]]
* We're talking about a game series that accounted for the possibility of the player [[GroinAttack shooting guards in the crotch]], and incorporated it into that bit with The Sorrow in ''[=MGS3=]''. "I'm useless now!" [[https://www.youtube.com/watch?v=xaz3O3o4Ndw One player]] went through the game killing every single enemy via GroinAttack just so the Sorrow's river would be full of emasculated guards.
** We're talking about a series that ''also'' accounted for the possibility that the player might have eaten a vulture who had, in turn, eaten human flesh. The victims of Snake's cannibalism-by-proxy also appear in The Sorrow's river, complete with a vulture on their shoulder. ("You ate me!")
** Hell, they've even accounted for the possibility of killing a guard while he's distracted by the Book item. His ghost will be holding the magazine, and he'll be complaining about not being able to see any more of it!
* You can also find a [[NiceHat crocodile cap]] and peek around corners while crawling, causing guards to believe you are some kind of indoor crocodile and ''freak out''.
** Similarly, you might try to use it on the dogs to see their reaction: The dogs will turn tail and flee if you do so.
* If Snake gets a stomach ache from eating rotten food, you can cure him with medicine ''or'' go to the medical screen, spin him around a dozen times, and then exit the screen and watch Snake puke up, fixing the problem. You can also escape the prison cell that way; make Snake vomit, and the guard will come in to check on you.
* It's possible to kill [[ThatOneBoss The End]] just after the cutscene in which he's fully introduced. If you do so, the boss battle is replaced by an encounter with the Ocelot Unit. If you damage but don't kill him after the above cutscene, whatever damage you've dealt to him will still be there when the boss battle actually starts. Should the End die this way, you have to dodge a wheel from his wheelchair when his explosives go off.
** Since The End is using tranquilizer rounds instead of regular bullets, getting hit by his shots reduces Snake's stamina gauge instead. If it's depleted, Snake passes out instead of dying and The End carries him off into the basement of a nearby base.
** You can save during The End's boss battle, and leave the console off for a week (or setting the system's internal clock ahead by one week). This results in him dying of old age. However, waiting less time than that before reloading the save allows The End to catch Snake while he's asleep and carry him off to the location described above. Killing the End this way has its own cutscene and CODEC discussion (where Snake expresses regret at letting the End die without a final battle, only for Major Zero to set him straight).
* Calling your MissionControl when you're imprisoned and saving the game has Para-Medic tell Snake about a vampire movie, to which Snake will reveal he's scared of vampires. Loading the game causes Snake to have a nightmare, which manifests itself as a demo for a scrapped action game called ''Guy Savage''. Sadly, this was removed from later ports.
* During the short period of time you have EVA in your party, so to speak, you can check her medical history. Turns out she has breast implants, eaten a Tsuchinoko, [[{{Squick}} and]] [[http://en.wikipedia.org/wiki/Proctitis Proctitis(NSFW image on Wikipedia page)]]. Is it possible for Kojima to troll his own series?
** This can be seen as FridgeHorror, if you consider that the proctitis is usually in the midst of electrical burns and other wounds caused by the sadistic pervert DepravedBisexual BigBad. Yep.
** Better yet, if you tranquilize her (which significantly slows down her stamina drain), she'll start talking in her sleep about Snake, The Boss and her dog, and makes several sexually suggestive double entendres.
** If you harass EVA enough times while you're paired up with her, she kicks you in the crotch hard enough to cause an instakill.
* [[http://metalgear.wikia.com/wiki/Metal_Gear_Solid_3_radio_conversations There is a Codec conversation for an absurd amount of elements in the game]].
* You know the torch you find in the cave? You can use it to set foes on fire.
** Also, you might get the idea to use the torch in Groznyj Grad's Underground Tunnel up to arriving at the area to face The Fury. The programmers anticipated this possibility, and added in a few seconds to The Fury's debut cutscene that shows Snake dropping the torch just for that specific scenario.
** The torch is only useful in the cave for a short while: if you wander in the darkness long enough, Snake's eyes will get used to it and the area will slowly get brighter and easier to see in.
* Shoot or stab Ocelot anywhere on the body without killing him. He will possess a bandage on that spot in all future appearances.
** There's a moment during the Virtuous Mission where Ocelot is knocked out on the ground. If you kill Ocelot while he's out cold, you get a Game Over with Colonel Campbell telling you that you created a Time Paradox, and that you shouldn't screw around with the future. The HD re-release even has an achievement called "Problem Solved, Series Over" for doing it.
* If you backtrack to areas you previously visited and called EVA there (more specifically in areas such as Dremuchij, Dolinovodno, Ponizovje, and Graniny Gorki, the four places where you can't call EVA upon the first visit due to either being absent [Ponizovje and Graniny Gorki], or hadn't even met yet [Dremuchij and Dolinovodno]), in addition to giving Snake the info about the location he is currently at, EVA will also ask Snake what he's doing all the way back there and remind him that he was supposed to go to the next destination.
* Various Codec calls and conversations to characters will also be slightly different depending on the player's prior actions. In Rassvet, for example, Snake's response to Zero in regards to the guard level depends on how the player handles sneaking past the guards. If the player evades detection completely, Snake will respond with "No one spotted me." Likewise, if he gets an alert or kills the soldiers, he'll respond with "I managed to get past them." and "I had to kill them... there was no other way. But no one will know we were involved." Also, call Sigint when the flame troops arrive at Krasnogorje. If the player got a bit too triggerhappy with soldiers, Sigint will state that the reason why they are after Snake is because he killed many of their comrades. Likewise, if the player restrained him/herself from killing anyone (except for maybe the Cobra Unit), Sigint will respond with Volgin sending them to torch him as revenge for disposing of The Pain, The Fear, and The End. In addition, Volgin's analysis on his body check on Snake before torturing him will be different depending on how frequent the player seriously injured him/herself gameplay-wise. If the player had very little, if any, (serious) injuries prior to being tortured, Volgin will state "What a beautiful body you have, like a newborn baby. But not for long..." If the player received a moderate amount of injuries, Volgin will state "Hmm... you've certainly seen your share of battles. Consider yourself lucky. I am about to show you what hell is really like." Lastly, if the player received a lot of injuries, Volgin will say "You're a tough one, my friend. A lesser man would be dead by now."
* If the player still had the magazine in their possession up to their capture, and then the player calls EVA upon leaving the prison, EVA will mention that she did not throw out any of Snake's equipment, and also reveal that she found out about the magazine, while sarcastically referring to it as a "fine piece of literature" towards an embarrassed Snake.
* If you want to preserve the mousetraps you can find in the Virtuous Mission for Operation Snake Eater, set them somewhere easy to find. They'll still be there a week later in-game and you can pick them up.
* You might be curious about what happens when wearing the Oyama facepaint and getting caught (and possibly other facepaint). The developers included at least one specific line uttered by the guards when caught (in the Oyama facepaint's case, they'll say "What's with that face?" with some amusement.)
* If you leave the transmitter in when you approach the waterfall, Ocelot's soldiers will try to attack you. Also, you get a [[CrowningMomentOfFunny hilarious]] bonus cutscene where EVA removes the transmitter.
* If you decide to, whatever reason, [[ViolationOfCommonSense use the Cigarette Spray]] against The Boss, she'll reel back.
* If you throw a grenade of some sort or shoot an RPG at Grozny Grad while you're on the cliffside you meet EVA at, the base will ''actually notice'' and send a helicopter to attack you!
* Para-medic has two sets of dialogue for every type of wild food in the game. If you haven't acquired it yet, she'll give you the "That area is home to the ___" version, and if you've got it, she'll give you the "I see you've captured a ____" version.
** The conversation will also differ depending on whether you've already eaten said food. If not, Snake will ask about how it tastes, eventually annoying Para-Medic, and if you have, Snake will describe the taste. For some of the foods, this information is actually missing in Para-Medic's handbook.
* Destroying food storages in an area will cause your enemies to suffer from hunger when you return later, affecting their performance. They get so hungry, in fact, that you can [[VideoGameCrueltyPotential throw them meat from a poison dart frog or a tarantula, and they will eat it gleefully... then keel over dead]].
** This also works against The Fear. If his stamina drops too low he try to find something to eat, and there happen to be a lot of poisonous frogs and mushrooms in the area where you fight him.
* Likewise, destroying the ammunition storages will make the guards carry only one magazine of ammo for their rifles. If they empty that clip after spotting you, they'll drop their rifles and chase you with their combat knives.
* Throwing a grenade towards a Gavial when it opens its mouth makes it swallow the grenade and blow up. This is notable because of the two locations that they can be found in, one is an area before you find grenades and the other one places most of them underwater.
* With the Subsistence edition of the game, the player is given the choice to use the original fixed camera or a camera that may be fully rotated around Snake. If you use this camera and look at the right angle at the end of the Virtuous Mission before healing Snake, the player can see The Sorrow's decomposed remains on the side of the river.
* There's a sequence near the end of the game where [[spoiler:the player gains EVA as a party member. You can check her injuries and food history, which has a fair amount of high-class food French and Italian Food, fitting with her background in the KGB. She also has some food that sounds a lot like what people eat in China. Because she's actually a Chinese spy, as we find out at the end of the game.]]
* If you're doing a PacifistRun, the game won't count [[spoiler:Ocelot and Volgin]]'s fights as kills if you drain their HP (as opposed to their stamina), since the former is a recurring character in future entries in the series and the latter is a RecurringBoss who shows up again at the end of the game. In fact, the only kill the game ''does'' force you to make is [[spoiler:The Boss, since terminating her was Snake's mission this whole time]].


[[AC:[=MGS4=]]]
* You can unlock, with some difficulty, the Solar Gun from ''VideoGame/{{Boktai}}''. It's very powerful, but difficult and impractical to use due to its limited ammo capacity and the fact that you can only recharge it manually in sunlight. Sunlight, of course, is a stock vampire weakness and the Solar Gun in ''Boktai'' kills vampires, so naturally, a player might consider using it on Vamp. He has a special animation and response to the shot (which is almost impossible to land due to how insanely fast he is), and fully-charged it can knock him down him in a single hit. Even better: the Solar Gun is technically a non-lethal weapon. Vamp is ''the only enemy in the game'' that can actually be killed by it.
* Similarly to ''VideoGame/MetalGearSolid3SnakeEater'', spinning Snake around on the model viewer/[=OctoCamo=] selection screen will result in Snake vomiting.
* Have Snake die in various ways, continue, and then call Rosemary. Snake (or, in the event that Snake was killed via an explosion, Rosemary) will begin the call stating that he got the feeling that he was killed before in the specific manner in which the player died.
* Certain locations in which you can participate in battles between Liquid's PMC forces and local militia change according to how the battle is resolved. You'd usually only spot this by backtracking.
* When [[spoiler: the ghost of Psycho Mantis tries to vibrate your controller again, the game will note if your controller can vibrate. If so, Mantis will scream, "VIBRATION IS BACK!" If not, he'll be flustered that his mind tactics don't work anymore.]]
* Similarly, if you set the controller to something other than 1 during the battle with Mantis (since the same strategy worked on Psycho Mantis in the original [=MGS=]), Snake won't be able to move. Otacon will then call up Snake and tell you that it's not going to work this time.
* Shaking the controller when Rose is talking will cause [[JigglePhysics her breasts to jiggle like Jell-O]].
* If you kill way too many enemies, you will hear Liquid's "You enjoy all the killing!" line from [=MGS1=], and then Snake will throw up. Like the time paradox scene in [=MGS3=]'s HD remake, accomplishing this after the trophy patch unlocks a trophy by the same name.
* Chapter 3 is a mission where you need to tail a man in a town that's under Martial Law, and normally you have to avoid being seen by the guards at all since Snake is wanted and his face will be recognized. However an alternative is to equip a face other than Snake or Otacon's, the Civilian Disguise, and remove all of your weapons. Then all you need to do is let a guard see you and cooperate while he pats you down, ''and the guards will ignore you from there on out so long as you don't whip out any weapons'' since they think you're just an innocent citizen.
** The catch to this, of course, is now the man you're tailing will think you're a civilian rather than a threat, and will ''take potshots at you to scare you off'' rather than try to run from you.
** A cutscene reveals that Old Snake was too being followed...no really you are literally being followed too, ingame! At any point during tailing the rebel, if the player looks back in the opposite direction to where they have been going they can spot the cloaked entity that appears in the later cutscene. Attempting to approach the entity will cause it to disappear.
* Snake's IPod is psychic. If at any point you're playing a song and stumble across something that references the earlier titles, an appropriate song from that game will play (if you've unlocked it, that is).

[[AC:Peace Walker]]
* There's a couple of joke DatingSim missions where you can date either Paz or [[GayOption Kaz]]. Normally, the game prohibits you from taking weapons into the dates, but if you hack the game to allow you to take them, you can kill them. When Kaz [[EverythingFades fades]], his glasses remain and clatter onto the sand.
** You can also use the team command "Say Goodnight" and they will... fall asleep. If you lay on top of Paz, she will dreamily state that "your beard hurts" and codec calls from other characters will imply that you are... umm... [[spoiler:eating her out (Not to mention they're not too happy about you taking advantage of someone who's unconscious.)]] Almost the same thing happens for Kaz, except his line of dialog is [[GayOption "Stop it... I'm not that kind of guy..."]]
* While the Codec lines in ''Peace Walker'' are usually generic or generic for the stage, thus making them hardly worth bothering with for the majority of players, making Big Boss stand on a specific riverbank in a specific stage after recruitment of Huey, the man who will become Otacon's father, leads him to remark that [[FutureShadowing he always gets a bad feeling when he looks out at the water]]. (''VideoGame/MetalGearSolid2'' revealed that Otacon's father committed suicide by drowning himself.)
* The game has two situations prepared depending on how well the CQC quick action cutscene turned out for the player: If the player successfully managed to do the CQC, the player will be able to use the ID card that Snake stole from Strangelove earlier to escape from the cell, although the call with Miller after Snake escapes will be somewhat short. If the player fails, the player can utilize a jigsaw strapped onto him, and after escaping, Miller's codec call will have him reference the Jigsaw.
* Given the Sling Post's obvious resemblance to a club or baseball bat, the player might get the idea to [[BatterUp smash it into enemies]]. The game programmed it for that specific purpose, and doing so will also activate a codec call where Miller will comment that it's not what its supposed to be used for.

[[AC:''Metal Gear Rising: Revengeance'']]
* It is possible to LagCancel out of Raiden's attacks instantaneously by tapping the Blade Mode button, causing Raiden to enter and immediately exit Blade Mode, which both wastes much less time and works on a greater number of attacks than cancelling with the dodge move does. There are some attacks that don't let you blade-cancel out of them, however, because blade-cancelling is an intentional gameplay mechanic on the part of [[Creator/PlatinumGames Platinum]] rather than a glitch or oversight, despite the game leaving it entirely to the player to discover this technique for themselves.
* There are multiple instances in the game where the enemies are threatening detained civilians, who can be saved if the enemies are eliminated quickly and stealthily enough. Once rescued, the civilian will thank Raiden and begin running in the direction of the nearest level boundary. If the player manages to catch up with them before they retreat behind the invisible wall and slashes at them, the civilian will be unharmed but stripped of all their clothing but their underwear. Calling your friends on the Codec immediately afterwards leads to angry, disguested conversations from each character, though the best one has to be Blade Wolf's.
-->'''Blade Wolf''': For all his achievements, man is still capable of such depravity.
* The [[CirclingBirdies stun icon]] that appears over enemies' heads (or the player's) have different words accompanying it, depending on who got stunned. Raiden and all of the cyborg enemies get "BMI ERROR", while Bladewolf and all of the unmanned Metal Gears get "AI ERROR". [[spoiler: Sam simply gets the word "[[ExactlyWhatItSaysOnTheTin STUN]]" over his head due to being an EmpoweredBadassNormal with almost no cyborg enhancements.]]

[[AC:Metal Gear Solid V: Ground Zeroes]]
* The story mission is comprised of multiple objectives which can be completed in any order the player wishes, and the game will rearrange or remove cutscenes to reflect this. For instance, the game expects first-time players to [[spoiler:rescue Chico first, use his intel to locate Paz and then extract her.]] However, if the player [[spoiler:rescues Paz]] before doing this, that portion won't trigger, nor will you [[spoiler:acquire Chico's tape]]. If you decide to [[spoiler:rescue Paz first and then take Paz down to the extraction zone after rescuing her, just like you would normally do with Chico]] the game gives you a unique cutscene between Snake and [[spoiler:Paz]].
** In addition, if you extract all the other prisoners and approach [[spoiler: Chico]] last, the cutscene is changed slightly so that Snake is instead startled by an enemy vehicle noisily approaching their location.
** ''Ground Zeroes''' side missions also have plenty of freedom in how you approach them, and the game reacts accordingly. Probably the best example is "Classified Intel Data", which centres around the revelation that [[spoiler: the tape your mole instructs you to collect is a fake planted by Cipher, and contains next to useless data]]. As it turns out, the [[spoiler: real tape is with the Cipher agent who has bullied the mole into cooperating]]. The game has unique dialog for almost every conceivable combination of objectives. For instance, if you follow the mole's instructions but [[spoiler: shoot out the camera next to the fake tape]] will cause Miller to comment on the cleverness of [[spoiler: the trap.]] However, if you [[spoiler: throw a smoke grenade into the room before grabbing the tape, so the camera can't catch you]], Miller won't even notice [[spoiler: the room was booby-trapped]]. Other ways of completing the mission, such as grabbing [[spoiler: the fake tape]] without talking to the mole or interrogating [[spoiler: the Cipher agent, causing him to drop the real tape]] will have Miller HandWave the ContrivedCoincidence of just how the hell Snake knows what he's doing without making contact with their source.
** It's not uncommon to see [[ChallengeGamer Challenge Gamers]] on Website/YouTube try their hands at a "[[spoiler: Both Tapes]] Run", which nets the player an extra score bonus.
* Shooting your own helicopter with the rocket launcher will cause Kaz to radio the messages "[[DudeNotFunny That's not funny]]."

[[AC:Metal Gear Solid V: The Phantom Pain]]
* D. Horse will not only poop on occasion, but can do so ''[[UpToEleven on command]]''. [[RefugeInAudacity Horse poop can even be placed on roadways, causing vehicles that run over it to skid out of control]].
* With the right upgrades, you can use fulton recovery on objects like a container. If you're standing on it, interacting with the balloon makes Snake grab the cable and immediately exfiltrate by fulton pickup. You can also use it to reach the upper floors of buildings.
** Active Decoy will pop out a balloon model of Snake. If thrown directly near a guard, the pop will blast him away, allowing players to do things like [[VideoGameCrueltyPotential throw guards off cliffs with your decoy]].
* Returning to Mother Base on your birthday (which the game asks for at the beginning) gets you a scene where [[spoiler:Miller, Ocelot and the Diamond Dogs throw Snake a surprise birthday party, including a special song and a birthday cake]]. With Quiet recruited, you get another special scene in which she [[spoiler:shoots open a crate of cigars for him by shooting out the letters "HBD".]]
* [=iDroid=] specific:
** The [=iDroid=] has two audio settings, headphones and speakers. The speaker option makes the music and briefing tapes much more audible and easier to hear, but also does so in-game; since you're using the speakers it becomes diegetic, [[PaintingTheMedium meaning the guards can hear what you're playing]] and will investigate the source of the noise.
** Using the Stun Arm while listening to tapes causes audible static feedback.
** One of the many unlockable tapes in game contains audio of a certain somebody in a porta-john having... [[ToiletHumor bowel issues.]] If you're hiding in a toilet and a guard is coming to use it or searching for you, turning on the [=iDroid=]'s speakers and playing the tape makes the guard respectfully walk away and leave you be. The same goes for animal SFX that are on certain tapes -- playing the goat sound-effect in Afghanistan, for example, will make an inspecting guard think you were just an animal and call off his search.
** Additionally, an Afghan and an African lullaby tape can be found in the respective locations. Playing the appropriate regional tape at night-time will make any guards that can hear it fall asleep at their post.
** There's even special tapes that contain guard voice clips. Playing them in appropriate situations will prompt the other guards to fall for it; playing a recording of someone saying "Enemy eliminated!" in the correct language will make alerted guards assume someone else killed you, and promptly radio in to end the alert.
* In most missions, SequenceBreaking is possible, as you can simply go to the objective before finding out where it is, or reaching an NPC before they reach a specified point. Several missions will have dialogue for this, and at least one, Episode 8, will lampshade your sequence break with Kaz questioning whether you have a "sixth sense".
* The Water Pistol has a surprising amount of detail put into it for a JokeItem.
** Enemies shot by it will be startled.
** Squirting it at electronics will cause them to short-circuit.
** Clothes will be realistically stained at the point you strike them
** Miller has a unique reaction if you try to use it on the Man On Fire.
** It's semi-transparent, just like many real-life water pistols.
** Spraying an enemy in the face causes them to block with their hands, leaving them open to a CQC strike.
** Using it on open flames (like burning barrels or torches) will extinguish the flame.
* Quiet's boss fight can be finished incredibly quickly, as all the player has to do (Rather than either engage in a sniper duel with her or sneak around and use the Silent Pistol to tranq her) is mark her location before calling in a supply drop on her head, which knocks half her stamina out. Do it twice, and the whole fight can be finished in a minute. This only works during mission 12, not during mission 40.
** It is actually possible to use this trick in Mission 40. Quiet's AI is much better and she will notice the airdrop coming in, unless she's too busy trying to shoot Snake. If you wait until the drop is about 10 metres above her, poke your head out of cover and then duck back in again she'll take a shot and get hit by the supply drop before she can react. Although on Extreme it takes five hits instead of two like in mission 12.
* If you destroy the comms equipment in the Eastern Communications Post in Free Roam Mode and then attempt the [="C2W"=] mission from a chopper, [[https://www.youtube.com/watch?v=1Uir3iO3sSc Ocelot will note that the comms equipment has already been destroyed]] [[{{Anticlimax}} and the mission will end instantly]].
* When Ocelot sends you to rescue Kaz, he says that Kaz can probably hold out for three days. If you use the Phantom Cigar to skip three days ahead and then try to save Kaz, he'll die and you'll [[NonstandardGameOver fail the mission.]]
* You can hold up enemy soldiers while they're standing in ankle-deep water streams. If you have them lie down, they'll lie down [[TooDumbToLive face first in the water.]] That's not the Foresight part, though. What is is that if you leave them like that, eventually they drown. And die.
* The first time a player gets attacked at one of their [=FOBs=], a cutscene reflecting on the matter will play on Snake's next return to Mother Base. Miller's response to Snake's question "Who did this?" will depend on whether or not the enemy player left the FOB without getting detected (which would give the FOB's owner to attack the enemy's FOB as revenge):
--> '''Snake:''' Who did this?
--> '''Miller''' ''(if the enemy player was spotted)'': A competitor. We know where they're based, even have a route planned out.
--> '''Miller''' ''(if the enemy player wasn't spotted)'': A competitor. But we don't know who. Can't pin down a route to their base.

[[AC:Multiple Games]]
* Try shooting the '''!''' above a guard's head if you're discovered. It stuns them momentarily.
* If the player tranquilizes the soldiers in the butt, heart, or the crotch, it will instantly knock them out like a headshot.
* In most games you can press a button during cutscenes to zoom the camera in. If you do this when the camera's point-of-view is looking through a set of binoculars or a handheld camera, the various numbers and bars change as well.

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* You can make Snake and Raiden kiss the bikini posters scattered throughout the game (and have people on the other end of the Codec comment on it [and have your character [[InnerMonologue comment]] on ''their'' comments]), get your Codec support mad at you for punching hostages or photographing the [[PantyShot panties]] of female hostages, destroy a huge amount of inanimate objects for the time, and get comments from Snake referencing things you won't find out he did until much later during Raiden's story if you call him at the right times.
** In regards to the posters, you can also knock on them to attract enemy attention like you would with a wall: if you position yourself so that Snake or Raiden taps their breasts, it will cause a "boing" sound, but if you position yourself so that the tap their crotch instead, it'll cause an alert sound and cause an exclamation mark to pop up and alert any enemies if they're nearby.
* There's a bucket of ice in the crew's lounge on the tanker. If you shoot it, not only does the ice fly out, it melts realistically; the cubes closer to one another melt slower than the isolated ones.
* Those ketchup bottles on board the tanker and Strut C of Big Shell? You can shoot at them and cause them to explode, also distracting enemies that way.
* Looking in mirrors:
** If you enter the only place with a mirror on the Big Shell and equip either the Camera or Sniper Rifle (weapons that force you into first person mode and which you won't have the first time you visit), you see that Raiden is properly rendered holding either.
** If you play around with the peeking mechanics in front of that mirror, you'll see Raiden sliding along the ground at lightning speed without any movements other than his breathing. Try it during the boss fight against Fortune and you can, with good timing, actually ''dodge her railgun shots without actually moving''.
** Shooting the mirror causes it to splinter realistically, and pieces will scatter across the floor. Raiden can still be seen in the shattered reflection. Speaking of that washroom, urinals, hand driers and sinks all work if you get close enough to them.

* In the Tanker chapter, you get a camera which is important to the mission, but can be used anywhere. It's not surprising that players might try to take photos of things which aren't important to the mission, and photographing posters, hidden characters, and female soldiers gets you secret replies from Otacon.
* If you take a photo of a poster of a man's chest and arm, Otacon will remark that "that explains a lot."
** Send a photo of the Commandant and Otacon will wonder if you're a fan of his. Send another few and he'll joke about making a panel out of it to put over your bed.
* The box warp returns in the form of a parcel sorting system.
* At one point in the game, you have to find a hostage by calling out to them, [[HollerButton with a button command that stops working after the hostage is found]]. If you then backtrack to the room with a parrot in it, and call out to the parrot enough times (ten or eleven, with no indication that what you're doing is recognized by the game), they learn to say the phrase and add it into their usual repertoire.
** The parrot can learn to say "Enemy sighted, requesting backup" if you get caught too much in that area.
** If you spray a parrot with the coolant, they flap their wings and say "this sucks."
* During the "find the hostage" mission you're dressed in an enemy uniform to avoid suspicion, where Raiden ultimately gets his balaclava torn off in a cutscene. Now let's pretend you snuck in using the [[NewGamePlus Stealth Camouflage]] instead. The game ''specifically'' gives you 10 seconds where you have to de-equip the directional microphone (and by extension get the uniform on as well) before Ocelot approaches, ''just so Raiden is wearing the proper uniform for said cutscene''.
* Speaking of the uniform, you'll notice it's still in your inventory despite being useless now that it's lost the balaclava. Turns out it's not ''completely'' useless: if you wear the uniform in an area where you'll leave footprints, the guards will ignore them rather than follow because they match those of their own boots.
* Plant some C4 in front of sea lice and blow them up while in first person mode: The sea lice will then fly towards the "camera" and splatter against it in a manner similar to insects on windshields of a speeding car.
* At Strut C, before talking to Stillman, go into the men's bathroom, stand in front of a urinal, look at it in first-person, and then call the Colonel. The Colonel will tell Rose to give Raiden some privacy, then Raiden begins to urinate and Rose tells him to let her know when he's done.
* Going into a toilet stall in the women's bathroom results in a very funny conversation.
* It's possible to see Snake in a box on the CD connecting bridge. If you shoot him, he gets a ! mark above his head and runs away. [[http://www.youtube.com/watch?v=cNoqJ8wVVyQ&t=6m15s If you call him afterwards,]] Raiden tells him about it. Snake denies knowing anything about it. In a later Codec call about the box, Snake irritably tells Raiden that thanks to him, a couple of his boxes were destroyed.
* See that bell on the wall in just one area of the tanker? Shoot it and it dings.
* Shoot the pans in the tanker's kitchen and they each play a different note, making a scale if you shoot them in order.
* When you are taking Emma across water, Raiden tells her to listen to his heartbeat so that she'll stay calm and doesn't panic. Take some Pentazamin, and Emma's oxygen lowers at a slower pace.
* After you get out of the water with her, you'll find a large group of sea lice in front of the elevator you need to use, which she refuses to cross: you can either use the coolant spray to chase them away, or just knock Emma out and drag her past them.
* In the Tanker chapter, the Marine Commandant Scott Dolph is giving a speech in the holds, and there is a countdown onscreen showing how long the speech has left (He sometimes takes a break from it to briefly exercise his troops and if the timer runs out at one point, he even decides to go on for just a little longer.) Shoot him with a sleeping dart on the head and the countdown stops until he can continue the speech.
* When the Commandant is giving his speech you can screw around with the projectors to make them switch between screens and show pictures of sexy women, which the soldiers turn towards. If you do it too many times in a row, the soldiers figure out something's wrong, turn towards you and catch you. [[ViolationOfCommonSense Run in front of the projectors]] and they'll spot you, too, even with the unlockable stealth camo on (Since it's still disturbing the light ray coming from the projector.)
* There's one specific platform near one of the locations where you need to take one of Ray's pictures where you can spot Ocelot, but he's there only if you don't have any weapons equipped and if you equip one, he disappears immediately.
* Meeting Pliskin:
** Soon after you meet Pliskin, if you aim your gun at him when he is sleeping he instantly wakes up, aim his gun at you, and says "I wouldn't do that if I were you." Attack him and he fights back.
** You can attack him later in the game after he gives you the sword. He fights back this time too.
** Sniping him during Emma's escort at the water will get you instantly sniped back. Apparently, he's really quick.
** If you knock him out the second time you meet him and call him on the codec, he'll be sleeping.
* You can anger Emma and Otacon by attacking Emma, or by knocking Emma out and promptly crawling over her body.
* If you aim the directional microphone at Emma at a [[http://www.youtube.com/watch?v=mZ8RRGYiCU4&t=5m45s certain part,]] you can hear her talking to herself about Raiden. Call her on the codec, and Raiden confronts her about it, and tells her despite her suspicions, his hair is real, not a wig.
* You can also listen to Snake wondering out loud if he needs to clear things with Otacon before he asks Emma out.
* Try having Raiden cartwheeling up some stairs. He'll trip if they're long enough. Cartwheeling ''down'' them is fair game, though, as the cartwheel is the closest thing to a jump button in these games - rolling as Snake along a staircase in either direction will cause him to trip as well.
** Somewhat amazingly, in [=MGS3=] Big Boss can roll up or down stairs without breaking his neck or otherwise injuring himself. Not quite sure how that one works.
*** Simple: He's Big Boss.
* The M9's hammer actually changes position when you use it - if you've just equipped it, the hammer will be down, but after firing a shot and chambering the next bullet, the hammer will be cocked.
* If you look to the far left using the analog stick [[spoiler:when Solidus is choking Raiden,]] the oxygen gauge will deplete more slowly. This is because [[ShownTheirWork you move your neck into a position where the choking is less effective.]]
* On the tanker chapter, there's a section where dozens of soldiers are standing upright to watch a presentation. If you hit one of them at just the right angle, you can actually knock them into each other, creating sort of a domino effect.
* When fighting Vamp, if you drop an [=RGB-6=] round in the water the blast will knock the wind out of him, depleting his OxygenMeter and forcing him to surface, even if it's nowhere near him when it goes off. This is how Depth Charges damage submarines in real life.

* There are two ways you can get a 'Mission Failed' which are highly unlikely in normal gameplay: falling down the lift shaft on Strut A and letting the bomb explode after the battle with Fatman. Both of these have their own specially-created images for the game over screen.

* Seagulls on the Big Shell:
** There are seagulls on the Big Shell, and killing enough birds as Raiden gets a call from the Colonel and Rose, who chew you out over your animal cruelty. ''Rose will break up with you'' and won't let you save until you apologize. Same goes for hitting hostages.
** If you chase away the seagulls and then look up in the sky in first-person, the seagulls will crap on you. Also, there are splatters of seagull poop that you can slip on, and there's one pipe covered with it that can cause you to slip off, fall into the water, and drown.

* If you don't take the SOCOM pistol from the truck in the heliport, the cutscene when Meryl holds you up after leaving the cell will be different. Snake will push aside the barrel of her gun instead of aiming back at her.
* If you attack Meryl when she's following you, she'll [[ArmorPiercingSlap slap you and knock you down]] normally, although if you hide in a box afterwards, she can't hit you back. However, if you do this in an area with wolfdogs that are friendly to her, she'll instead whistle and cause one of them to pee on your box, and wearing that same box afterwards will cause the wolfdogs to ignore you due to the scent.
** Having Sniper Wolf's handkerchief equipped will cause the wolfdogs to ''follow'' you without attacking and it doesn't require any additional gimmickry from player's part, but once Snake [[spoiler:returns it to Wolf after he kills her]], you obviously can't use it anymore and need to resort to the box trick described above.
* Beating Ocelot quickly has him compliment you in the following cutscene. Beating him after a longer fight changes his dialogue accordingly.
** If you take a long time to get from the Dock to the main game, Colonel Campbell will chastise you and wonder if you're rusty. If you did VR missions prior to starting the main campaign, Snake will bring them up.

* When Solid Snake fights the Hind helicopter, {{Mission Control}} tells you to use the TV's stereo to locate it if it flies offscreen. If your TV is on mono mode, Mei Ling and Naomi Hunter make fun of you while Colonel Campbell assures you that "there's more to being a good person than just having a stereo television."
* In the fight with the Cyborg Ninja, he makes a big scene out of the fact that you can fight hand-to-hand. Indeed, most of your weapons are useless. You can, however, freeze him for a few seconds using a chaff grenade. If you do, not only can he criticize Snake for not being what he was, he can also break the rules himself and use his sword.
* On the way to the fight with Vulcan Raven, you can kill the ravens you see. If you do, Vulcan Raven is ''pissed'' when you encounter him.
* Depending on the player's decisions, Snake can either enter the top ventilation shaft to first infiltrate the tank hangar building or the bottom ventilation shaft. The decision will be reflected with Master Miller's introductory call, where, if the bottom shaft is chosen, he will explain to Snake about the rodents that Snake is currently following.
* Depending on how successfully the player escapes regarding the ketchup or not, the programmers had Snake's response when the player calls Otacon be different regarding the results: If the player fails to escape via the ketchup (either due to not using it at all, or the player wasn't quick in escaping), Snake will coldly refuse to acknowledge Otacon's involvement in the escape. If the player succeeds in escaping via the ketchup, Snake will express some surprise that the trick actually worked.
** Despite Johnny's greater cone of vision than the other Genome soldiers in the game, it looks like it would be possible to evade his sight entirely if you hid in one specific corner of the room -- so, naturally, the [[spoiler:DARPA Chief's]] body is planted in that corner, preventing the player from using it.
* The player is told that, by contacting weapons analyst Nastasha Romanenko, they can receive additional information on nuclear tech and their own weapons. By equipping an item or weapon, she will go into depth about real-life manufacture and attributes; should the player call her with the cardboard box equipped, [[UpToEleven she will explain (in great depth) the manufacturing methods, structural types, and even common uses of boxes.]]

* In the Armory South (near where you face Revolver Ocelot) is a hallway with several high level doors and gun cameras. One room has the camera, but the other has absolutely nothing of note except what appears to be a diesel generator. Its ''only'' reason for existing is to justify the {{Air Vent Passageway}}s in the game being large enough to crawl through: one codec call mentions the facility must have a generator and that it would need large air vents to run.

[[AC:''Metal Gear'' / ''Metal Gear 2: Solid Snake'']]
* In [=MG2=], if the player is having trouble decoding Kio Marv's message of "HELP! WIS. [=OhIO=]" and calls Master Miller afterward, he'll immediately figure out that [[spoiler:it's Marv's transceiver frequency.]]

* Psycho Mantis can read ''the player's'' mind by reading memory card data, providing a detailed analysis of the player's proficiency at the game (how good they are at stealth and combat, and how frequently they've saved their game), and suggesting that the player enjoys certain games like, say, ''VideoGame/{{Suikoden}}'' or ''[[VideoGame/CastlevaniaSymphonyOfTheNight Castlevania]]'', [[WebAnimation/AwesomeSeries for instance,]] or ''VideoGame/SuperMarioSunshine'' and ''[[VideoGame/SuperSmashBros Super Smash Bros. Melee]]'' in the UsefulNotes/NintendoGameCube remake. Even better, in the Japanese version, having save data from both VisualNovel/{{Snatcher}} and VisualNovel/{{Policenauts}} unlocks a special message from HideoKojima.
** If for whatever reason you're unable to use the second controller port, Colonel Campbell will eventually reveal an alternate way to beat Mantis: destroying the busts in the room.

* When fighting Vamp, if you drop an [=RPG-7=] round in the water the blast will knock the wind out of him, depleting his OxygenMeter and forcing him to surface, even if it's nowhere near him when it goes off. This is how Depth Charges damage submarines in real life.

* If Snake gets a stomach ache from eating rotten food, you can cure him with medicine ''or'' go to the medical screen, spin him around a dozen times, and then exit the screen and watch Snake puke up, fixing the problem.

* In the Armory South (near where you face Revolver Ocelot) is a hallway with several high level doors and gun cameras. One room has the camera, but the other has absolutely nothing of note except what appears to be a diesel generator. It's ''only'' reason for existing is to justify the {{Air Vent Passageway}}s in the game being large enough to crawl through: one codec call mentions the facility must have a generator and that it would need large air vents to run.