History VisualNovel / NineHoursNinePersonsNineDoors

** Eerily and cryptically subverted in the "Safe" ending, where the players run out of time to escape from the ship and are doomed to drown after Zero declares a Game Over on top of [[spoiler:Snake dragging Ace to die with him in the incinerator for his sister Clover's murder]]. However, Zero informs a despondent Junpei that Zero themselves "have lost" despite the dire circumstances. [[spoiler:This is because Junpei chose the wrong choices and Akane (the real Zero) in the past wasn't able to give him the right information as a result in this timeline.]]
** [[spoiler:Played straight in the GoldenEnding where even though the players (save for the 9th man) escaped the Gigantic's Nevada replica and are free to go home, Zero (Akane and Aoi) succeeded in their plans to save Akane in the past and get revenge against the original Nonary masterminds with three of them dead and [[PunkInTheTrunk Hongou at the heroes mercy]], with the siblings still at large.]]

* ActorAllusion: In the ''Nonary Games'' port, Ace is voiced by Creator/RichardEpcar, who uses a voice similar to [[Franchise/LupinIII Daisuke Jigen]], which becomes more promient when [[spoiler:he wields the golden revolver like Jigen's weapon of choice, is shown to be very unscrupulous in general (while lacking Jigen's heroic traits) and in the "Safe" endin calls the late Clover a "[[CharacterCatchphrase bitch]]".]]

* BaitAndSwitch: In the "Nonary Games" port, [[spoiler:the final puzzle has letters alongside numbers, suggesting that you’ll need to use the hexadecimal system again as alluded to by the hints. The actual solution requires you to just literally spell the word "PASSWORD" from a fresh board reset which solves the numbers portion for you if done correctly, which doesn’t use any letters above on the grid.]]

* AirVentPassageway: [[spoiler:Door 2 has a room that has one of these.]] It leads right to [[spoiler:the Incinerator within Door 9.]]

** The remaster for ''The Nonary Games'' adds the flowchart mechanic from later installments in the series, eliminating the need to play through the entire game several times to get all the endings, as well as adding the option to jump to specific points to get the information needed to unlock certain paths.

** There's foreshadowing all over the place; one particularly subtle bit is in a ''{{panty shot}} gag'' of all things.

** One bit of foreshadowing was added in the ''The Nonary Games'' re-edition when June compares the shape of the furnace to kamaboko (fish cake). [[spoiler: Who else uses food-based comparisons? The narrator.]]
** Once the party discovers [[spoiler: Snake's body]], one of the grisly details Junpei notices is an open fracture on the corpse's left arm, [[spoiler: which at some point gives away that it's not Snake's body at all, as he has a prothetic left arm.]]
* ForWantOfANail: A large number of 'nails' exist: every possible choice- from [[PlayerCharacter Junpei]]'s travel partners to whether or not you take a bookmark- influences your fate. [[spoiler:Akane is watching all of them, to find the best fate for her to follow]].
** A little toy ''doll'', of all things, ends up playing a pivotal role in Akane's backstory. While [[spoiler:escaping the first DeadlyGame with Seven]], she [[DiabolusExMachina dropped it]] and [[IdiotBall ran back to get it]]... which led to her getting caught by [[spoiler:the murderous creator of the game and getting thrown in the incinerator room... which led to her TraumaticSuperpowerAwakening... which allowed her to establish a psychic connection with Future!Junpei...which saved her life... which meant that, several years later, she had to trap Junpei, herself, and seven others in a similar DeadlyGame so Junpei could connect psychically with Akane's past self, fulfil the paradox, and ensure her survival]]. If not for that ''one'' [[ItWasAGift important item]] falling at that ''one'' crucial moment, the entire game's events could have been averted.

** Even the NewGamePlus is integrated into the story, as [[spoiler: past!Akane is having visions of every possible future during the current Nonary Game. In fact, one of the bad endings is ''required'' to get the good ending, as past!Akane conveys information gained during that ending to Junpei, allowing him to [[SequenceBreaking Sequence Break]] his way past a keypad lock.]]

** The remaster for ''The Nonary Games'' adds the flowchart mechanic from later installments in the series, eliminating the need to play through the entire game several times to get all the endings.

* BigBad: Plays with this in a surprising way. The current [[DeadlyGame Nonary Game]] is being run by a mysterious person in a GasMaskLongcoat getup known as Zero/[[spoiler:[[SamusIsAGirl June]]/[[LoveInterestTraitor Akane]] and [[TheDragon her secretary]] [[WhiteHairBlackHeart Santa]]]]. As it turns out, they are actually [[spoiler:{{Well Intentioned Extremist}}s]] trying to [[spoiler:punish the four men responsible for the first game and to get Junpei to save June's life. Time travel loops and all that]]. So [[spoiler:the actual Big Bad]] ends up being [[spoiler:Ace, or rather, Gentarou Hongou, [[CorruptCorporateExecutive CEO of Cradle Pharmaceuticals]], creator of the original Nonary Game and murderer of Past!Akane]] as the person who set everything into motion.

* ChekhovsGun: Plenty, including an actual gun. A minor one is the notebook and pen found in the first puzzle suitcase.

* MyFriendsAndZoidberg: In the routes that have the most plot significance, the only one whose presence isn't really explained [[spoiler:with their connection to the previous Nonary Game]] is Lotus. She just kind of exists within her dynamic with Seven, to force splitting at times (see JerkassHasAPoint), [[spoiler:and her getting captured and being taken hostage by Ace in either major ending.]] The only way you can find any relation connecting her to the major MythArc [[spoiler:is to follow a deliberately stream-lined path that only goes to the Sub ending, that reveals her kids were part of the game.]]

* PoliceAreUseless: [[spoiler:In the case of this game, the law enforcement lets a [[CorruptCorporateExecutive group of executives]] conduct the [[DeadlyGame Nonary Game]] on nine children nine years ago because their chief, Ace/Gentarou Hongou, [[{{Narcissist}} wants to see the faces of other people]] and is unable to due to prosopagnosia. Might also count for Akane in the present day, who repeats the repeats ''that'' game nine years forward [[MindScrew so she can save herself in the past from the future by connecting with her past self through the awakening to morphogentic fields she received nine years ago in that past Nonary Game]]]]. Zig-zagged, however, in that [[spoiler:Seven is actually a police officer, and he saves those children from that game in the past, but he's the only police officer to be shown ''actually'' doing something about it.]]

* PoliceAreUseless: [[spoiler:In the case of this game, the law enforcement lets a [[CorruptCorporateExecutive group of executives]] conduct the [[DeadlyGame Nonary Game]] on nine children nine years ago because their chief, Ace/Gentarou Hongou, [[{{Narcissist}} wants to see the faces of other people]] and is unable to due to prosopagnosia. Might also count for Akane in the present day, who repeats the repeats ''that'' game nine years forward [[MindScrew so she can save herself in the past from the future by connecting with her past self through the awakening to morphogentic fields she received nine years ago in that past Nonary Game]].]]

* {{Feelies}}: If you pre-ordered from Gamestop online, you got a replica of the bracelets. Thankfully, it functions as a normal watch. Also, you used to be able to buy them for 5 bucks from the [[http://www.aksysgames.com/store/#999watch official store]]. Now they're collector's items that sell upwards of 200 dollars.

** If you got the True Ending, you'll have gone through nine puzzle rooms. [[spoiler:Furthermore, the final puzzle in the True Ending is a sudoku puzzle, which is all about sets of nine.]]

*** If you beat a puzzle without using all the items and look at the items again before you fully leave the area Junpei will say something about him not knowing why he's carrying the item and he will throw it away later. Which only makes sense, why would you run around carrying a ripped shower curtain all day?

* BatDeduction: The participants of the current Nonary Game frequently theorize it's a telepathic experiment used to find ways to access other people's thoughts from a long way away, as well as having the potential to control others to near memetic levels (one person does it, suddenly hundreds of people have the same compulsion). They end up being wrong for two reasons. [[spoiler:1) The first Nonary Game had much simpler reasons: Ace wanted to access other's visual perceptions from around him because of severe prosopagnosia. 2) June is partially able to look through the timelines and control Junpei, but ''only'' Junpei, and in the incinerator at the final puzzle neither June nor Junpei can control the other, only speak to each other and show each other things in their side; it's up to the other to actually do the task that needs transmitted.]]

*** Junpei himself does this in the path where he insists on going through door 3. Santa insists that they can't go that way, so he tricks June and Seven into scanning their numbered bracelets with him; Santa beats Lotus and Clover to the door and goes with them (the True ending reveals that [[spoiler: he had to in order to maintain the illusion that his and June's bracelets were actually 3 and 6]]). [[WhatTheHellHero Lotus and Clover are furious with Junpei once he comes back,]] since it shows that he was willing to possibly sacrifice three people just so he could stay with June.

%%** Junpei, in some instances.

* EleventhHourSuperpower: [[spoiler:Rescuing Snake from the coffin]] in either of the major endings is the thing that changes the course of the ending.
** [[spoiler:In the "Safe" ending, his arm's a fake, which means he can remove his bracelet and be a non-issue during the doors, allowing the others to enter the 9 door without leaving anyone behind. Afterwards, his rage for Clover's death means he's able to take down Ace out of sheer willpower - even after taking 6 revolver shots - leaving the others to escape the incinerator alive.]]
** [[spoiler:In the "True" ending, Snake's rescue from the coffin means Junpei, Seven, and Clover have a way to enter the other 9 door in pursuit of Santa (who has taken June hostage and forced Ace and Lotus to go with him). It's only after entering the 9 door and mostly solving the library puzzle that Snake is able to reveal the entire backstory of the previous Nonary Game, something that you've received only hints and suggestions of the whole game.]]
** [[spoiler:Junpei's ability to access the morphogenetic field is this, too. The entire point of the current Nonary Game is to save June using the morphogenetic field to give her the answer to the final code and save herself. While everyone else has a connection to the Nonary Game and some are transmitters or receivers themselves, in the "True" ending Junpei unlocks the ability to be both a transmitter ''and'' a receiver, and only after Santa takes June hostage and all seems lost.]]

** It may be unintentional, but the digital root of [[spoiler:the numbers of the bracelets the four Cradle Pharmaceutical members wore during the game]] is 9. [[spoiler: 1(Hongou)+2(Nijisaki)+6(Musashidou's true no.)+9(Kubota) = 18, 1+8 = 9.]]
* {{Area 51}}: Building Q, out in the middle of the Nevada desert, where part of the Nonary Project experimentation is carried out... [[spoiler:and also where the events of the game, unbeknownst to most of the cast, play out.]] In a nod to the real status of the site, it is a private building of a multinational corporation, rather than a government building.

* NeverTrustATrailer: [[spoiler: The Ninth Man is played up in promotional materials and game art as having just as big a role in the plot as everyone else. Which he ''does'', kinda, but only long after he's [[WeHardlyKnewYe killed in the first hour of the game.]]]]

* NewGamePlus: Upon beating the game for the first time, the game starts tracking which endings you've earned. You can also "begin with memories" which allows you to speed past dialogue you've already seen and dims choices you've already made in previous play-throughs.
** Also a rare instance of [[spoiler: the NewGamePlus being canon, as thanks to time-travel morphogenetic field shenanigans, Junpei is able to know things in the GoldenEnding route [[RippleEffectProofMemory that he only learned in other routes.]]]]

* RedHerring: There are several, the most major being [[spoiler:Ice-9 and Alice]]. [[spoiler:You still need them to reach the True Ending.]]

* GameplayAndStoryIntegration:
Uses the DS's dual-screen functionality for [[spoiler:the plot twist that you're playing two people]]:

** [[spoiler:A rare example in the form of NewGamePlus: you are simply June exploring a new future timeline.]]
** In the ''Nonary Games'' release, you have the option of playing the game in one of two modes that can be switched at will during cutscenes: ADV (Adventure) Mode, which shows the game without any added narration, and NOVEL Mode, which adds a black text overlay with narration. [[spoiler:The significance of the two modes is part of TheReveal during the True Ending due to the lack of a second screen, with the mode names changing to "JUNPEI Vision" and "AKANE Vision" respectively during the final puzzle.]]

** Murder by way of explosives in a victim's stomach might be a reference to the memetically infamous "small bombs" theory in ''VisualNovel/UminekoWhenTheyCry''.

* LuckyTranslation: Akane's Japanese alias is Murasaki (purple, from the 6th color of the rainbow and her clothes), has nothing to do with June, her alias and the sixth month in English. [[spoiler:Which makes Junpei's comment about as a child 'not seeing her after June' (the season), foreshadowing.]]

* {{Retcon}}: 999 was originally made as a standalone title. When ''VisualNovel/VirtuesLastReward'' was released, it changed some of the already-stated-by-the-creator backstory. [[spoiler:Ace is retroactively made a member of Free the Soul and Snake's robes became Free the Soul robes, erasing a plot point about Lord Gordain being the originator of the nonary games.]]

* GainaxEnding: [[spoiler:Junpei and his companions have finally escaped the Nonary Game, and everything seems good and well (except that Junpei has to start a pursue for Akane)... And suddenly you see a naked Egyptian woman hitchhiking in the middle of the desert. And the game just ends with that, implying that Junpei will get to know her in the next installment. And he does.]]
** [[spoiler: The Safe Ending is this until you get the True Ending, [[MindScrewdriver which answers a lot of questions about it]]. Everything happens in a perfectly understandable manner until Ace and Snake's death, at which point Junpei returns to the Chapel to find June apparently dying from her fever. Suddenly, June disappears when Junpei isn't looking, and Zero cryptically announces their own failure over the loudspeaker before Junpei is knocked unconscious with another gas grenade. Roll credits.]]

** Unfortunately, what's lost is a pronunciation pun, which is rather important during the climax of the True End, and makes no sense for the players unless they know Japanese. [[spoiler:Specifically, the most common pronunciation for the number ''9'' in Japanese is "kyu" which is a homophone of "q". This also gives more meaning to the "Captain's Quarters," a door with a "q" where a witness is waiting for Ace to confess to his crimes; if he chooses to do so, he will be freed.]] An attempt was made to fix the most important part by changing it into a visual pun ([[spoiler: the instructions were moved to a card in Junpei's pocket, and the number 9 does awfully like a lowercase letter q]]), but a {{Flashback}} towards the end of the game mistakenly shows the wrong thing, making most players forget that detail. The ''Nonary Games'' re-release fixes the mistake.

** [[spoiler: In Japanese Akane and Aoi mean "red" and "blue", respectively. When code names are chosen, Akane's is "Murasaki" which means "purple" and is derived from the number 6 due to some Japanese wordplay. This also ties into the ending where the voodoo doll is thought by Junpei to be a "budou doll", "budou" meaning "grape". As a result they end up naming it "Murasaki" or "purple". There are consequently numerous instances of the colors red and blue being used throughout the game along with a few cases of combining to form purple.]]

* LuckyTranslation: Akane's Japanese alias is Murasaki (purple, from the 6th color of the rainbow and her clothes), has nothing to do with June, her alias and the sixth month in English. [[spoiler:Which makes Junpei's comment about as a child 'not seeing her after June' (the season), foreshadowing.)]]

** Memories Of the Escape lists all the rooms to be gone through in the game, except they are listed in an odd order. It starts with the Third Class Cabin, your starting point, but then it goes through the the rooms behind doors 4, 7, 1, 9, 5, 8, 6, 3 and 2, in that order. This references [[spoiler:the path to the True Ending (4→7→1→9), the path to the Safe Ending (5→8→6) and the path to the Submarine Ending (any→3→2).]]

* AllThereInTheManual: There's a bit of backstory that's only available [[https://zeroescape.fandom.com/wiki/Answers in an interview with the game's director]]. Be aware of unmarked spoilers for 999's sequel, VisualNovel/VirtuesLastReward! Avoid scrolling down past the 999 section.

* AdvancedTech2000: The Pushmaster 5000 used for the ''VideoGame/{{Sokobon}}'' puzzle in the cargo hold.