Ace Combat has details not covered in the games proper, such as the stories of the aces as found in the Assault Records or the full history of the Ulysses asteroid.
Action 52 came with a 12-page comic book explaining the origins of the Cheetahmen. The Action 52 manual, however, was quite inaccurate (it appears the game summaries were based on projections rather than the final product). It did offer a mailing form you could fill out to get more complete instructions on each particular game, but they haven't been discovered or even documented on the internet.
AI War 2 has a very extensive amount of lore, but you wouldn't find much of it in game. Particularly, most of the alien races are not elaborated upon in game, but lots of details have been released by the developer.
American McGee's Alice, in the deluxe addition, comes coupled with an illustrated "casebook" of Alice from the insane asylum she's staying in. It gives many details about the causes of particular events in the corrupted Wonderland, as well as giving hints about proper ways to defeat certain enemies and bosses.
Many of the villagers in the Animal Crossing series have official descriptions which reveal more about them as individuals that are not present within the games. These include, but are not limited to, the e-Reader cards compatible with the GameCube installment (which have long since been discontinued) and the Japanese website for Animal Crossing: City Folk.
Most of the plots for the Angry Birds series of games are all covered in their commercials.
Even though the basic controls of Arc Style: Baseball!! 3D are displayed all the time on the bottom screen during a game, crucial information regarding rules, steal mechanics and specific body build abilities are only found in the game's electronic manual.
The Ar tonelico series is blatant about this, between the scarcity of information on world history in-game and the Translation Train Wreck that plagues it. What are the Teru? What is a Heart of the Land, and why does Jakuri seek it? Why is Saki so important? Who is this Ciela/Horus? All of these are found scattered in the setting encyclopedias, the booklets accompanying the album releases, and the columns in the defunct official site.
There are numerous tie-in books and comics that explain backstories of major characters which are only ever hinted at in the games, particularly with Daniel Cross, whose appearance in Assassin's Creed III will be completely confusing unless you've read Assassin's Creed: The Fall and The Chain.
Assassin's Creed: Initiates contains most of the information from the books and comics, while providing even further details on the modern day Assassin-Templar conflict with regular surveillance updates.
There's tons of this in Asura's Wrath, which can be found in the pre-order art book, such as where the Demi-Gods come from, how they came to be, the time period the gohma started attacking, explaining the origins of Mantra and how it became a power source, and several other things for stuff that is unexplained in the already fleshed out story of the main game.
Almost all of the powerup names in the Backyard Sports series nowadays come from the manuals for the respective games.
The Batman: Arkham Series has a series of comic book minis filling in the gap between various games. The comics show events only alluded to in the games, such as how Arkham City came to be constructed in the first place (and how many of the villains were captured), the Bat-Family's exploits between games and Batman's thoughts on the death of the Joker at the end of Arkham City. They also provided origins for a few of the game's original characters.
BlazBlue has lots of material (covered in manuals or tie-in books) that's not present in the games, and most plot points won't make sense if you don't do your research. What makes this a particularly egregious example is that most of said material hasn't been released outside of Japan, which means the only way to read it are by fan translations.
Breath of Fire IV, and to a lesser extent, Breath of Fire: Dragon Quarter, also have this occurring. In IV in particular, there are certain bits about the game's plot and storyline that only ever were covered in the official artbook; some have been incorporated into the (presently-ongoing) manga adaptation, some haven't. Of course, all of this plus the two phone-game side-stories are not available outside of Japan and China, so we in the BoF fandom tend to be really grateful for Scanlation...
Bust A Groove, a little-known rhythm game for the PSX, was a game entirely about having dance battles with people ranging from twelve year olds and disco playboys to a thirty-foot tall robot and twin aliens. The game itself offers absolutely no explanation for these battles, or the characters themselves for that matter. The manual reveals that the characters are battling one another in order to receive their heart's desire using Dance Power. These wishes are vaguely alluded to in each character's ending cinematic, but never stated outright due to ever character being a Silent Protagonist.
The sequel has the same problem, though it's compounded by the fact that not even the booklet describes the game's plot, just each character's backstory.
The titular rockets in ChuChu Rocket! each have a pilot with a name and a unique design, but you won't actually see them outside of the manual. Their only actually appearance in any video game at all has been Sonic and Sega All-Stars Racing.
The game comes with Jeremiah's journal, where he explains how the Covenants were cursed and how they all met their untimely end. Also, you can find a transcript of some chat with one of the game developers here.
According to Word of God, the brotherhood of monks was supposed to guard the different nexi across the world (mentioned by Patrick at the end of the game, when he says there are more gates). They also continue their watch after their death (that's why they haunt the catacombs).
Cloud: The game's booklet is the only place that calls the dark-and-white cloud interaction a "cloud fight".
The first two Crash Bandicoot games had this affliction. If you wanted to know things like Brio's relationship with Cortex, what makes Coco so special and how N. Gin got the missile stuck in his head, you had to read the manual. Various basic gameplay mechanics were also never talked about, which wasn't so much of a problem in the original due to Crash only being able to run, jump and spin, but new moves in Crash Bandicoot 2: Cortex Strikes Back such as sliding, High jumping and body slamming are never even mentioned. This got better in the third game where it explains how to pull off new unlocked moves, and better still in Crash Team Racing where Aku Aku or Uka Uka would have many pop-up tutorials to explain how to do things.
Did you know Cytus has a plot? It's true. It's buried within the game's description in the app stores so it's kinda hard to find, especially if you don't usually read those. It involves robots in a distant future, in case you're wondering.
There's also one for the DLC "L" chapter, which involves a godlike being who is perceived by the beings of a heavenly civilization as disastrous and coming down to the human world, with those in heaven chasing after him with disastrous results.
Dead or Alive started with a literal version in the PlayStation 1 version, where the only story were backstories told through rather tiny text written on the outer edges of the pages over the course of the entire instruction manual insert in the jewel case. The second game wasn't much of an improvement; while there are now cutscenes between the fighting, they're incredibly short and only provide the bare minimum of the plot. Kasumi's story mode is particularly egregious: Something about a Kasumi clone, Hayabusa wants her to stop her mission, Ayane wants to eliminate her, Kasumi thinks Hayate is her brother... all rather perplexing if you just go by what the game presents you with.
Destiny has its Grimoire cards, unlocked by in-game achievements and not viewable in the game itself. These have tons of in-universe information and speculation on all the different characters, technologies, and factions; the Taken King expansion even includes a book on the history of the Hive race as written by the Big Bad. In-game, absolutely nothing is explained except in the most general terms. It's actually heavily implied several times that even the player character has no idea what the hell's going on; for instance, the existence of the post-human colony in the Reef has to be explained to them when a quest requires them to go there.
With the advent of the Deus Ex Universe, an Expanded Universe initiative that encompasses comics, tie-in games and books, a large chunk of background information about what characters were doing between games is this:
Alex Vega's appearance in Deus Ex: Mankind Divided can come off as jarring to players who haven't played the tie-in (formerly tablet) game Deus Ex: The Fall or read the Hard Line novella (which explains how she met the Juggernaut Collective and Adam, and is only included in the Collector's Edition of the game).
The "how" and "why" of Adam's recovery after the destruction of Panchaea in Human Revolution (and his subsequent enlistment with Task Force 29) is covered in the tie-in novel Black Light. This information is very scarcely referred to in Mankind Divided.
Diablo's manual contained most of the plot and backstories of all the races and units, which isn't found in the game proper. This includes a very vivid description of a little boy being transformed into Diablo.
Everything that happened between Diablo III and it's expansion, Reaper of Souls, is explained in the novel Storm of Light. This includes how the Hoardrim was reformed, and why Tyrael choose to hide the Black Soulstone on Sanctuary rather than locking it away in Heaven.
Venerable Amiga / DOS adult (pixel art boobs and gore) Point&Click Adventure Game DreamWeb originally came with the "Diary of a (Mad?) Man", which greatly fleshed out the main character, his mental problems, and the world he lives in. In fact, the story of the diary is far more detailed than the game itself; it also features a progressive rendering of symbol seen in dreams, necessary to unlock one of the final doors.
Doki Doki Panic had the Big Bad, Wart, already defeated when he tried to take over Subcon, according to the manual. The manual also stated that the family's children fought over reading the book and they accidentally tore off the book's ending page, causing Wart's defeat to never happen and allows him to reach out and snatch the kids (the missing page also explains why World 7 has 2 levels and not 3). However, the game itself only shows the kids reading the book before Wart snatches them.
Illwinter's strategy game Dominions 3 has a massive 300 some-odd page manual including a complete list of the hundreds of spells and a description and sample strategy for all of the myriad nations, alongside the admittedly limited backstory to the game. That still doesn't include stats for most of the national units, details on many unit attributes and spell effects, province stats, etc.
The manual for 4 actually does contain stats for national units and details on spells, but the author wasn't able to keep it up to date on all the balance changes and nations added in patches.
The plot of Donkey Kong Country is almost entirely in the manual; the only hint in-game that there's foul play going on is when DK or Diddy enter the cave in their treehouse where they hoard their bananas, which elicits a sad response from them when they find out it's empty.
Donkey Kong Land one-ups it: Not only is the backstory of the game explained in the manual, all of the worlds and level names are covered there. The latter, understandably, is because of the hardware limitations on the Game Boy.
DOOM (2016) and DOOM Eternal have a ton of codex entries scattered throughout their levels that greatly expand upon the background lore. Despite the slightly increased emphasis on plot, reading them is still treated as wholly optional.
The various ghouls and player characters from The Ghouls' Forest series of Doommods, as well as the multiplayer Ghouls vs. Humans, used to have detailed bios available on the author's blog. They were then removed (and no known copies exist) because the author felt they were "no longer needed".
It's only in his bestiary entry (and only in the Definitive Edition) that it's revealed that Indignus was the one who destroyed Havens Above and slaughtered the Watchers.
Several details about Don Rodrigo's late wife Gerbera, most notably her name, are only revealed through side materials. This example contains a TRIVIA entry. It should be moved to the TRIVIA tab.As all of these materials were released exclusively in Japan, she does not receive a name in any localization.
The obscure adventure game The Eidolon came with a long and detailed story in its manual/diary, full of Steampunk science and dream logic. It also told you flat-out how to face down certain creatures by detailing the writer's experiences with them. The game itself just starts up in the pilot seat of an unidentified vehicle with nothing but blackness visible.
Several of the games force you to dig through in-game supplemental material to make sense of the setting and the plot. Some fans have assembled an online archive of the game supplemental material.
In fact, the series' notoriously complex and intriguing lore is probably one of the best examples of this trope. The lore involves everything from the entire universe being All Just a Dream, to a time-traveling cyborg paladin, to the world being destroyed by a magical robot and people moving to the moon (which is actually the dying corpse of a god), to the stars actually being holes in space, to absolutely everything about Vivec, a more-than-omnipotent god who may or may not be a hermaphrodite married to the god of rape and who has one of the most confusing Multiple Choice Pasts in all of fiction. Incredibly, almost none of this is presented in the games themselves, which, outside of occasional hints at something larger in in-game books, generally look like generic High Fantasy to somebody not versed in the lore.
Daggerfall's manual has a 'history' portion that details not only the history that can be found in-game, but also elaborates in more detail the events that lead from meeting the Emperor to waking up in a cave than what the game, itself, does. The manual also includes a handy genealogical chart for the three main noble houses of the Iliac Bay, although that information can be found in-game (just not graphically and in one place). Daggerfall's manual, however, is also notoriously shaky. Because they wrote the manual for features they had in planning, but never got around to release, the manual gives reference to objects which don't exist.
Everyone knows that the Nazi-esque Thalmor in Skyrim are hell-bent on banning Talos worship because they believe he is the last thing keeping Mundus (the mortal realm) extant and doing so will kill him, ending Mundus and returning their spirits to a state of pre-creation divinity, right? Actually, that isn't mentioned anywhere in Skyrim at all. That idea comes from "Obscure Text" writings by former developer Michael Kirkbride. However, there is plenty of supporting evidence in-game indicating this to be the case anyway, and most fans have adopted it as official lore as a result.
Elite Frontier: Elite II came with a packed-in travel guide describing some things in the game's universe that were never actually encountered in-game, such as Marlin Fish in Ross 154 or meeting the Emperor of the Duval Empire in person. Still, they make for exhilarating mental vacations.
Elite Dangerous has a series of novels exploring the lives of people living in the early 34th Century while also expanding on the legends of the Thargoid race.
A lot of information in Elsword is out of order or just barely scratched upon, mainly the storyline for every character and their interactions with others. Playing the game straight, you'd only see glimpses of plot in each character's dungeon clear quotes. External sources explain the actual story of the game and dilemmas in each city you visit, as well as detailing major points in the plot (such as Elsword and co. finding Eve after defeating King Nasod, Add's encounter with the team after defeating Victor, etc.). The recently released "(city) Clear" videos, El Type magazines, and job-change comics are a few examples of these sources.
Invoked in Empire Earth's fourth mission of the Russian campaign when the briefing recommends you to check out the manual to learn more on cybers' abilities.
Each successive installment of Escape Velocity had more relevant lore in the manual than the predecessor: the original game was not this trope at all, Override has a couple of things that were never explicitly stated in-game, and Nova has eight 'preamble' PDFs, one of which is a Universe Chronology, six of which go into deeper detail about the importantnote That is, each corresponds to one of the major and exclusive to one another storylines of the game civilizations and groups of the 'verse, and one which is an example of a traditional song sung by one minor group.
Evolve has quite a bit of information only known because the writer often posts on the forum. The most noticeable examples are the stories about the hunters prior to the game, found here.
The names for the monsters and some characters in Fairune are only found in the Monster Collection screen. Hope Girl's name in Fairune Blast is Girl from Another World, and is named Hinome in the achievements list.
The Emperor from Final Fantasy II got his name, Mateus, in a novelization. Though the only "canon" (IE, in-game) appearance of it is the summon based on him from Final Fantasy XII, and his ultimate weapon in Dissidia Final Fantasy, "Mateus's Malice". The same novelization explains the origin of his powers: He made a pact with Satan to gain control of hellspawn to conquer the world. It also explained that he gained control of Hell because of his disposing of Satan.
The Compendium of Final Fantasy VII was named not just to cover the original game and five other spin-offs, but also to cover a large amount of background information and lore that was only covered in guidebooks, novels and novellas:
On The Way to a Smile is a collection of novellas that are mostly set in between the events of the original game and Final Fantasy VII: Advent Children, focusing on minor characters' actions, as well as setting up new character Denzel. "Episode: Denzel" was later used as an animated short that was included in home media releases of the film.
Turks: The Kids Are Alright was an official novel published in 2011, which follows the titular team as they try to rebuild their order in the interim between the original game and Advent Children.
The Maiden Who Travels The Planet is a short novella published in the Ultimania Omega guidebook that shows Aeris' perspective from the point in which she is killed by Sephiroth to her spirit using Holy to drive back Meteor at the end of the original game.
The last name of Gast (Aerith's actual father, and the founder of the JENOVA Project), Faramis, was only revealed years after the fact in the 10th Anniversary Ultimania book.
Final Fantasy XIII also has a novella called Final Fantasy XIII Episode Zero - Promise - which includes how Lightning first met Snow, even given more reasons why she disapproves of his relationship with her sister, how Fang and Vanille awaken on Cocoon and try to adjust to it, about Sazh and his son Dajh, including a POV description of the Euride events from Fang's eyes, another chapter about Hope going on vacation in Bodhum with his mother, Serah and Snow going out to look for Lightning's birthday gift and a flashback to the War Of Transgression where Fang and Vanille were originally branded as l'Cie. It basically gives more background information on certain scenes that are already in the game or just adds a chapter that explains something small.
Then there is Final Fantasy XIII -Episode i- which takes place right after the events of the game and are written from Vanille and Fang's POV after they have put themselves into Crystal Stasis and watch over the others being reunited, even swearing to find a way to get Vanille and Fang out of the Crystal Pillar and their sleep.
Final Fantasy XIII-2 Fragments After is a compilation of short stories that revolve around Lightning and how she got into Valhalla and is adjusting to being there, Noel and Yeul and their blossoming feelings, about how Snow actually left on his journey (which is mentioned in a short dialogue in-game, heavily abridged apparently) to find Lightning, Alyssa and her trying to fight fate and make sure she is not ret-gonned out of existence, which is what Noel and Serah's actions will result inas well as a story of Yeul's entire life as a seeress and finally a story of the events of the end game told by a certain Yeul's perspective.
Finally there is also Final Fantasy XIII Reminiscence: -tracer of memories- that meets up with Sazh and Dajh, Hope, Sera, Snow and even Lightning after the events of Lightning Returns: Final Fantasy XIII, in case the player was curious what happened with the other characters, other than Lightning, after the final cutscene. As the majority of these were never officially released, so none of this was known to most people. Though some of the stories in these novels are already in the game and are merely expanded on in written form.
The only way to fully understand the events in Final Fantasy XV is to view some of the tie-in media, which was noticed and pointed out in many reviews published during the game's launch.
The Platinum Demo of the game is actually a standalone tale that is being recounted by Noctis to his friends, and details an experience years before where he has to travel through a fragmented dreamscape with the help of his guide, Carbuncle. This demo was officially canonized in the Brotherhood anime (see below).
A King's Tale is a standalone game that was originally released as a Pre-Order Bonus for ordering through Gamestop or EB Games, and recounts a tale that takes place 30 years prior to the start of the main game.
Prologue: Parting Ways follows Noctis and his friends' activities just prior to the start of the main game. It was previously released as an audio drama in Japan, but was later converted into an e-book and released as a free download.
The short film Omen was originally released during the 2016 Paris Games Week, and follows King Regis as he has a premonition about his son and asks the Crystal of Insomnia which course of action he should take.
Kingsglaive is an anime prequel that takes place during the events of the game's first chapter. Not only does this anime explain and show events that are only referenced during the game (notably, the death of King Regis himself), but it also utilizes footage and ideas that were originally planned for its early Versus XIII incarnation.
Brotherhood is a six-part anime series which was released on Square-Enix's Youtube channel, and chronicles the backstory of Noctis and his companions.
Path of Radiance and its sequel Radiant Dawn had its backstory explained at the official Japanese website for the series, namely that Lehran and Altina founded Begnion together and they were the first couple to bear a Branded child. Some of this information could be found in game if the player was willing to go through the game a second time while performing certain extra tasks, but said tasks border on Guide Dang It!.
Fire Emblem Awakening has an extensive background site in Japanese that provides many extra details about the world or characters, such as that Gangrel knew Aversa was a Dragon with an Agenda all along, and that Valm is indeed the same continent as Valentia from Fire Emblem Gaiden, and was named after its founder Alm, the hero of that game.
Flashback came with a short comic book explaining the story. The key details are given in the second level, with a few minor characters and events missing.
Friday Night Funkin': Much of the game's story is currently untold within the game itself, but a story does exist, and is occasionally explained by the devs on Twitter and during Twitch streams, like why Pico and the Spooky Kids are fighting the Boyfriend during their respective Weeks.
The English release of the Galaxy Angel manga includes a manual detailing things that the writer left out from the game.
Game & Watch: The plot to later games such as Zelda and Climber are hidden in their manuals.
General Chaos came with a 16-page comic book explaining the origins of the conflict between Chaos and Havoc and giving each member of The Squad a humorous personality.
The instruction booklet for the first game came with notes on everyone's relationships to one another, and a map of the continent you would be exploring. A similar cheat sheet came with The Lost Age, which in addition to helping you keep tabs of your adventure, helped newcomers who hadn't played the first game catch up on what was going on.
Dark Dawn is by far the biggest offender in the series. In addition to the map and the character relationship charts (the printed one blows the secret of Matthew's ancestry; a version that only leaked to the internet blows the plot-relevant secret of Amiti's), the game itself has an in-game encyclopedia, which is filled with new information whenever words in red text show up. The encyclopedia entries provide a lot of information the NPC chatter and cutscenes do not, and without them, you're going to have a hard time making any sense of the plot, and likely miss several key points and quite a bit of foreshadowing and world-building.
In Grand Theft Auto: San Andreas, Sweet, Big Smoke, and Ryder are only known by their nicknames and their given names are never said in the game. The instruction manual for the game, however, reveals in the beginning of the page that Sweet's full name is Sean Johnson, Big Smoke's full name is Melvin Harris, and Ryder's full name is Lance Wilson.
The notorious 1985 flop The Great Space Race for the ZX Spectrum came with the back-story for every character in a series of comic strips (which actually looked like first-drafts drawn with marker pen) in the manual. This kind of thing was common in the 8-bit era as memory and cassette/disk space was limited and traditional media was often used to provide background and atmosphere for game worlds.
Guilty Gear has Japanese-only drama CD's, Bibles/Material collections and novels and press kits you'll need (among other things) to get all the plot of the GG universe, especially most anything about the Crusades themselves or the inner workings of the Assassin's Guild.
The Halo series has several examples, to the point where you should probably seethis and/or this for all the details.
Halo: Combat Evolved begins with the characters having just discovered the titular installation. What happened before that is covered in Halo: The Fall of Reach. Another novel, Halo: The Flood, tells us what everyone else (both human and Covenant) was doing on the ring while the Chief was running around, while Halo: First Strike explains what happened between the first and second games (like how Johnson survived and how the surviving Halo 1 cast got back to Earth).
Halo 2 ends at the start of an epic battle. Halo 3 starts at the end of the same epic battle. The battle itself is covered in the comic series Halo: Uprising.
If you want to know the true reason why the Covenant declared war against humanity, you'll have to read Halo: Contact Harvest.
Halo: Reach is notorious for this: the significance of Dr. Halsey, why she distrusts NOBLE Team, the Forerunner artifact, Cortana, the Pillar of Autumn and even the setting won't make full sense unless you've not only played the first game, but read the 2010/2011 The Fall of Reach reprint, Halo: Ghosts of Onyx, Halsey's Journal (which only came with the Limited/Legendary edition of the game), this in-universe communication on Bungie's official website, and the Waypoint Data Drops, in order to settle what might otherwise seem to be Halo: Reach's contradictions with earlier Expanded Universe material.
In Halo 4, numerous players who were not familiar with the Kilo-Fivetrilogy, The Forerunner Saga, and/or the terminals from Halo 3 and 4 expressed severe confusion about the story, ranging from why the Chief is fighting the Elites again to the very identity of the Librarian and the Didact.
Haunting Ground: Daniella's name is one of these, as in the game itself she is only referred to as "The/That Maid", but her character models in the Bonus Room and the instruction booklet name her. This is a particularly jarring example, as every other character - even Fiona's mother Ayla, who only appears in a single Flashback, is named. However, given her driving motivation, Daniella's name may have been left unsaid on purpose.
Haunting Starring Polterguy: The game's backstory is only given in the manual. Polterguy was a standard 90s teenager who liked skateboards. As those were crap, he died in an accident. Polterguy wants to tell it once but somehow chooses not to.
Hellsinker is nigh incomprehensible to the uninitiated; it's filled to the brim with cryptic scenes, proprietary terminology, and strange gameplay mechanics, the latter two of which are explained in the manual. Before the game and manual were fan-translated into English, Western players took to consulting incomplete guides and wikis (one guide infamously states "I have no idea" in response to an element of the button configuration menu) trying to make sense of the game.
The original game has a large manual which describes the history and technology of your faction leading into the campaign, and goes into quite a bit of detail. However, the intro cutscene usefully summarizes the parts which are directly important.
Homeworld: Cataclysm also provides a long, detailed backstory in the manual, along with descriptions of all of your ships and a lot of enemy ships. Again, though, the really important backstory is summarized in game.
Homeworld 2 plays this straight, though. To really understand the backstory and what's going on, you need to either have shelled out $20 for the strategy guide or waited until the developers released their internal history documents onto the web. Made worse if you played Cataclysm, since it takes a few missions to realize none of the world-building from that game was canon.
Hotline Miami 2: Wrong Number had a tie-in digital comic series that came out before the game was released, and explains the backstories of main protagonists and general setting of the game.
The NES version of Hydlide had an opening screen in which a demon casts a spell and turns a princess into three fairies. The full explanation of this was left to the manual. The PC-88 version at least had a screen of text at the beginning of the game.
Bad or hasty localization can also cause this. The Nintendo GameCube version of Ikaruga only had the basic story outlined in the manual. Everything else was supposedly in game... but it was removed and not even the Japanese remains. Granted, you'd be lucky to even read half of it before it disappeared, but at least it was there in the other versions.
The singleplayer story mode of Impressive Title has Natsume, a larger-than-average winged feline, hunt down Aquanite because of her Mixed Ancestry. But given the campaign's short playtime and dialogue, it's impossible to know exactly what Aquanite's heritage is, or even what kind of animal Natsume herself is supposed to be without looking at their creator's DeviantArt. Turns out, they're both Faiyali (basically cats with wings) or in Aquanite's case, part Faiyali and part Seisan feline. And interestingly enough, you'd never know that Aquanite was wearing a Tracking Device on her tail, and that her blue "fur" was actually feathers without looking at her character reference sheet.
Indiana Jones and the Last Crusade has many puzzles that require the use of information within the game alongside information that only exists on the Grail Diary booklet included with it. It is possible to finish the game without it, but much harder, as some puzzles will see you being forced to simply guess the solution, which is problematic since, unlike in other LucasArts adventure games, you can die here for doing things wrong. Fortunately, digital editions tend to include the Diary as a downloadable file. Unfortunately, the Diary's requirement isn't ever mentioned in the game itself, so people can get really stumped looking for a solution not knowing the answer is a few clicks away. This is further complicated by the fact that the Diary also shows up as an item in-game, so when told to look for answers in the Diary, they will look at the wrong one.
inFAMOUS got in on this trope too. In between the first and second game there was an interquel comic published and released by DC. Although the main story was still understandable enough without reading the comic, a number of the game's subplots are only resolved in said comic, like Cole coming to forgive Zeke, whatever happened to Sasha, Alden, and Moya, and Zeke learning that Kessler is Cole's future self.
Infidel came bundled with a copy of the protagonist's diary, which detailed the backstory of how he came to learn of the pyramid he's exploring in the game, and the progress of his expedition to find it, culminating in his subordinates deciding they've had enough of him and abandoning him alone in the desert. Apart from giving more depth to the plot, it gave a clearer picture than the game itself mostly manages of what an unpleasant person the protagonist is, which is vital to appreciating the game's Karmic Twist Ending.
Everything that happened between the Infinity Blade games are all covered in its two novels. The second and third game only briefly cover the last and important parts of the novels (The main character is actually a Deathless named Siris in the second, and Raidriar ends up allying with Siris and dies during his encounter with the Worker of Secrets in the third), but not how the events let up to them.
Iron Helix: While the in-game cutscenes do a decent job on explaining the story, the manual provides more detail. For instance, the fact that Humanity and the Thanotosians are in a cold war is only mentioned in the manual, not in the game proper.
The plot of the PC game Jazz Jackrabbit 2. The villain from JJ1 has stolen the diamond from Jazz's fiancee's engagement ring. You have to get it back before he uses it to power his time machine and erase rabbits from history. Didn't read the comic in the manual? Then you wouldn't know any of this.
Keep Talking and Nobody Explodes: This trope is the whole point of the game, actually. There is a literal bomb defusal manual that you can print out which one player reads to another player, who handles the bomb.
Killer7: The developers put out a companion book, Hand in Killer7, that provides some backstory and explanation to the game's characters and events. Though this information is hardly any less confusing than that provided by the game itself, and often outright contradicts the game altogether. Given the nature of the game, this has to be deliberate. Although some say it's based on a beta version of the game's story, that still doesn't explain the fact that sometimes the book even contradicts itself.
Also, to understand who the characters are (especially some of the characters not in cut scenes, like Coyote and Con) you have to read the manual with the game. It's also helpful for learning the characters' abilities, which is necessary for solving some of the puzzles.
Suda also wrote a story that was published through magazines, giving backstory on Dan's time as a police officer. It was entitled "killer is dead", but was never actually finished. Interestingly, Suda would much later reuse the name for a different video game.
While it's not critical to playing the games (other than for the Copy Protection), the King's Quest manuals have massive amounts of Back Story and character notes. The Peter Spear player's guide cranks it Up to Eleven with a creation myth for the universe the series is set in, documents "written" by the characters, and a fictional history of Daventry. And that's not even touching the Fanon on the universe...
Kolibri's story is told in the manual. The game proper has no story text and doesn't explain what empowered Kolibri, why some of the animals and plants have gone berserk, or why so many of the level names are references to cancer.
The game itself had a rather standard Save the Princess plot in its opening crawl. The manual, however, revealed that the princess you were saving was actually the current princess' distant ancestor who had been put into an eternal sleep because she wouldn't reveal the location of the third Triforce piece to her brother and an evil wizard. It also explained that this is the reason the princess is always named Zelda — in honor of the one under the spell.
The blonde Kokiri in The Legend of Zelda: Ocarina of Time was named "Fado" on an old version of the official site. She's one of the few named Kokiri in the games, a leftover from her important status in the beta.
Hyrule Historia, an encyclopedia of sorts for the Zelda mythos released for the franchise's twenty-fifth anniversary, confirms or expounds on a lot of story details that were either ambiguous or outright overlooked in the series, serving as the answer to pretty much any question a fan would have. Most notably, and to much controversy at the time, it finally gave an official timeline for all the games up to that point.note For the record, the controversial bit wasn't the split timeline. While some fans had still insisted on a linear timeline, most of the fanbase had already decided that a two-way split into a "Child" and "Adult" timeline after The Legend of Zelda: Ocarina of Time was the best explanation for the franchise's continuity, if it even had one. The controversy was the reveal that Ocarina of Time created a three-way split, as the idea of Link dying in the final battle being a canonical outcome never occurred to anyone.
Game elements introduced in The Void update don't have an in-game introduction.
The original version of LucasArts' Loom included a 30-minute introduction on an audio cassette. However, if you've got a pirated version lacking the cassette, you can play the game without missing much. Also fits if you legally download the game off Steam, or anywhere else.
In Low G Man, the infamous "then they came" Excuse Plot is explained in better detail in the manual.
The Big Bad of 'Lunar: The Silver Star Story: Complete'', the Magic Emperor, has a huge air of mystery about his true identity for much of the game...provided you never look through your ocarina's playlist.
The in-game biography for Lunarosse provides a lot of details about the characters that never comes up during regular gameplay.
Up until 2014, Marvel: Avengers Alliance had Marvel XP, a database which often gave extra details about the plot in its News section and Dossiers, and was cross-connected with Avengers Initiative.
The special edition of Marvel vs. Capcom 3 came with a one-shot comic book that tried to weave a more coherent story, since all you really have to go on in the game itself are the intro sequence and the various non-canon endings.
Mass Effect has a very detailed Expanded Universe which necessitates the reader delve into the books or comics to better understand the underlying forces or motivations behind certain protagonists and antagonists.
Redemption (also a prequel to 2) explains how Liara T'Soni attempted to get Shepard's body back from the Shadow Broker in much greater detail and how she first met Feron. The Lair of the Shadow Broker DLC references, but doesn't fully explain, the events mentioned in the comic series.
The Mass Effect 3: Datapad app is absolutely filled to the brim with messages from supporting characters and squadmates, which do a lot to flesh out the state of the galaxy during the Reaper invasion (and what characters were doing during and after major missions) and isn't featured proper in the game itself.
The Invasion comic series explains how Aria was forced to flee Omega because of General Petrovsky before the events of the third game, and how the Adjutants arrived on the planet in the first place. The series is referenced only briefly in the Omega DLC itself.
The tie-in animated movie Mass Effect Paragon Lost explains how the Alliance military developed a permanent countermeasure against Seeker Swarms, which is seen in gameplay (but never addressed or acknowledged) in 3's multiplayer mode.
Mass Effect Evolution is a comic book mini-series that served as a prequel to the first game. It focused on The Illusive Man, revealing his real name, that he was a mercenary under the command of General Williams, and how his long painful journey in The First Contact War led to his creation of Cerberus.
Explanations about the true nature of the Maverick virus in the Mega Man X and Mega Man Zero games, as well as the fate of the Guardians at the end of Zero 3, can only be found in the Rockman Zero Complete Works sourcebook. The events of the ELF War and the backstory for the Eight Judges from Zero 3 are similarly only explained in Japanese drama tracks on an OST remastered CD.
The Mega Man Battle Network and Mega Man Star Force series are full of alphanumeric codes that do various things (Number Trader codes for free stuff, compression codes to make NaviCust parts smaller, etc.) You can find some "legitimately", i.e. in-game, but not all. Where are the rest? Japan, of course. They appear in magazines, during anime episodes, and so on. Japanese fans then post them on the net so the rest of us can get them.
There are also manga prequels to the original series as well. These fill in some of the details behind the game's plot. For example, the prequel manga for Mega Man 9 notes why older robots don't have to worry about the expiration date imposition, show the Robot Masters from the first game attempt to stop the rampage of the latest set, and even explains why Mega Man doesn't have a chargeable Mega Buster after five consecutive games with one. As a Continuity Nod, said explanation was given by Dr. Cossack, who was blackmailed by Wily in the fourth game but working for Dr. Light from the fifth game onward.
And in 2012, the Robot Master Field Guide was released, featuring detailed bios on every single RM to date as well as the series' main characters, in an attempt to compile as much supplementary material as possible in oneEnglish manual.
The entire plot of the original game, simple as it is, exists solely in the manual and packaging; Mega Man 2 was the first in the series to include an introductory cutscene explaining the premise and how the major characters relate to each other.
Mega Man 3 has a relatively complex narrative by NES standards. To continue Dr. Light and Dr. Wily's cooperative peace-keeping project, Mega Man's mission is to retrieve energy crystals from the mining worlds, suggesting the stages take place in space instead of local geographical areas. Dr. Wily appears to reform, only to eventually return to his evil ways...but possibly due to a rushed production, the game is missing an introduction actually telling you that Wily has reformed, making the mid-game reveal that he's gone rogue again incredibly puzzling if you didn't read the manual. "Gamma", mentioned in the game once, is the peacekeeping robot and final boss, as explained in Nintendo Power.
In Extra-planetary War Chronicles: Metafight, the Japanese version of Blaster Master, the manual explains that the game takes place on the planet Sophia the 3rd in 2052, and is being invaded by the emperor Goez and his army the Inbem Dark Star Cluster. Kane and Nora ride the Metal Attacker to defeat the emperor and his army. The game shows the Metal Attacker vehicle leaving a hangar, and ends with the blue haired protagonist staring at the sky, followed by an ending screen featuring both protagonists in chibi form.
The Japanese manual for the MSX2 version of Metal Gear included bios and artworks of the main characters and bosses (including an explanation of Schneider's motive for creating the resistance movement), and gave the specifications of TX-55 Metal Gear as well as the designs for it. A fan translated version can be viewed here. In contrast, the English manual for the European MSX2 version only included the standard playing instructions, although it's not as bad as the English translated version of the NES port's manual, which pretty much butchered the story.
The Metal Gear 2: Solid Snake manual also elaborated quite a bit on the game's story and other things, and was absolutely vital to playing the game and understanding the story (in fact, it was even needed for a certain part of the game that probably made it far too difficult to be beaten otherwise). For instance, it elaborated on exactly how Solid Snake managed to infiltrate Zanzibarland, the history of Zanzibar Land as well as its statistics, including military strength and natural resources, a history of FOXHOUND, and bios for the main characters. It also explained a bit about the landmarks of Zanzibar Land, and the backstories of several bosses, and specifications of several vehicles encountered in the game, including the Goliath tanks, which were originally supposed to be fought as a boss but were removed due to time constraints and kept as part of the scenery on the first floor of Zanzibar Building. It also explained how to use tap codes in this game, which makes the manual absolutely necessary to use to get Dr. Madnar's frequency, and thus get further into the game. A fan translated version can be viewed here.
The originalMetal Gear Solid included a segment where Kenneth Baker tells Solid Snake that the only way to contact Meryl Silverburgh is to look at back of the "CD case" to find out what her frequency. This is a reference to an actual screenshot on the back of the game's boxart, which depicts Snake conversing with the character in question via Codec.
Metal Gear Solid 2 also featured a fictional novel titled In The Darkness of Shadow Moses: The Unofficial Truth, a tell all account written by Nastasha Romanenko exposing the true events of the Shadow Moses Incident from her perspective. This novel elaborates a lot on the Shadow Moses Incident from the support group's end.
There was a leaked voice casting document for Metal Gear Solid 3: Snake Eater that elaborated on some details on the main characters. It gave the real name of Major Zero (David Oh), and elaborated on a few things about some characters, such as mentioning that the American colleague of Granin was actually Otacon's father (which was later confirmed by Metal Gear Solid: Peace Walker).
Although it is heavily implied in Metal Gear Solid 3: Snake Eater, the Metal Gear Solid 4 Database is also the only place you'll find a direct confirmation that Ocelot is the son of The Boss and The Sorrow. The Metal Gear Solid 4 Database also elaborated on what happened with the Metal Gear Gs as well as the history of Shadow Moses. However, the database received criticism for not resolving some things, getting other things wrong and retconning info.
The packaging and manual for Snake's Revenge states that the Big Bad is a dictator named "Highrolla Kockmamie" (which is actually a play on the Iranian leader Ayatollah Khomeini). However, he's only mentioned in the packaging and manual and doesn't appear in the game itself. The Big Bad of the game is actually Big Boss. Curiously, despite the fact that Snake's Revenge is clearly intended to be a Metal Gear sequel, the manual and packaging description actively avoids using the name "Metal Gear" at any point, going as far as to refer to the enemy's ultimate weapon as the "Ultra Sheikh Nuclear Attack Tank".
In Metal Walker, the manual gives more backstory on the setting, and your character's name, Tetto. Metal Walkers and Busters were originally created as mining robots.
Metroid opens with a title narration saying "Emergency Order: Defeat the Metroid of the planet Zebeth and destroy the Mother Brain the mechanical life vein. Galactic Federal Police M510." You'd have to read the manual to know why the Metroids have to be destroyed.
The game doesn't even have an opening narration like the first game does. It just plops Samus on the planet surface with no plot direction, other than a little counter that goes down every time you kill a Metroid. The manual goes into much more detail about how the Galactic Federation declared that the Metroids were too dangerous after the events of the first game; multiple teams sent to investigate SR388's Metroid population went missing; and Samus was hired to quell galaxy-wide panic by exterminating the entire Metroid species.
The different areas of SR388 lack names in the game itself, but are identified as Phase 1 through Phase 9 in Nintendo Power Volume 37. Unfortunately, while very similar for the most part, these names do not necessarily correspond to the area names in Metroid: Samus Returns, which can make matters a little confusing when discussing the two games.note Return of Samus begins the naming scheme with Phase 1 being the planet surface and Phase 2 being the first set of Chozo ruins, while Samus Returns does not include the Surface in the naming scheme and starts with Area 1 being the first set of Chozo ruins. Phase 5 and Phase 6 were combined into Area 4, while Phase 8 was split into Area 6 and Area 7.
Ridley, The Dragon who appears in almost every game, is an extremely intelligent and cunning (if bloodthirsty) military leader. Not that you would know this just by playing the games, as all he's ever done is screech, roar, and claw at Samus whenever he shows up. Further, the way he keeps coming back after being defeated (eating corpses and then absorbing their biomass to heal injuries) is never mentioned outside the manga.
The Prima guide for Metroid: Samus Returns reveals a few pieces of information not disclosed by the game itself, such as revealing that Ridley's half-Meta, half-normal form is called "Proteus Ridley."
Microcosm apparently takes place on another world in the distant future, involves a multi-generation war between MegaCorps, an assassination attempt, and Cyberpunkish corporate espionage. You wouldn't know this from playing the game. It's a Rail Shooter with controls that makes Baby Jesus cry himself to sleep at night, and an opening FMV that is almost as long as The Godfather II but explains NOTHING about the labyrinthine story. The manual's story lasts for more than twenty pages, including a three or four chapter story, an atlas of the fictional future star system it takes place in, and an long essay on why the MegaCorps are fighting and how crappy their planet is.
The series has an amazingly complex storyline, but you wouldn't know it from playing the game. Not to mention the players don't find out which characters' endings are canon until the next game in the series is released. Mostly the main plot involves someone betraying someone else and trying to conquer the multiverse, only to be betrayed, only for the betrayer to be betrayed, only for the original betrayer taking back his throne, rinsing and repeating. Everything else involves the heroes trying to defeat/free themselves from the current overlord, and being blindsided by the next uurper. This one doesn't resemble the movies at all, either. The Gambit Pileup is hilariously lampshaded in the intro movie of Mortal Kombat: Armageddon: Everyone in the series is attempting to rush towards and climb some sort of ziggurat, happily killing each other along the way.
Mortal Kombat vs. DC Universe had a one-shot comic that was only included with the special edition release. It expanded on the plot of the game by showing how the two worlds were merged together, and also explained the absence of fan favorites like Johnny Cage and Robin.
Minor example: the first Mortal Kombat is the only game in the series whose instruction booklet lists the characters' ages. Lui Kang, despite being The Hero, is actually the youngest Kombatant in the game at 24 years old. Kano, at 35, is the oldest of the human characters, and this means he's 60 in Mortal Kombat X due to its 25-year Time Skip.
The strategy guide is a famous example. The game itself is an exercise in mystery, as you don't know where you are, what the purpose of linking books are, who Sirrus and Achenear are and why you're helping them, with the ending simply being a Sequel Hook. The tie-in strategy guide, however, gives much greater context to what happening, via giving the Player Character a name, thoughts of his own, greater understanding of what he's doing in the various Ages (and why) and his thoughts on Atrus and his sons. There's a reason why it's one of the top-selling strategy guides of all time.
There were also three novels written for the series, the first two of which explain all the background of Atrus, his family, and the D'ni civilization. The third fills in some of the gaps between Riven and Myst III: Exile.
Much of the backstory in NieR is kept in the supplementary book Grimoire Nier, including the game's connection to Drakengard and the beginnings of Project Gestalt.
Ni no Kuni's manual is over 300 pages long, and is the only place to find in-game spells, potion recipes, and the like.
Because of its ever-changing focus on different parts of its game universe, Nexus Clash has an in-depth wiki detailing the broader lore, including the parts that aren't spotlighted in-game at the moment. The current iteration also has a lot of the history of Laurentia on the wiki, though most of it can be clued out from things you can find in the game if you search hard enough.
Octopath Traveler: Details regarding ages, backstories, occurrences in the timeline, and other unmentioned things in-game are talked about in the official setting and guide book.
Inverted in Odin Sphere as the game manual contains a few tidbits of the lore not directly mentioned in the story. Also, you're better off NOT reading at the very least Velvet's character profile in the manual, because the fact that she's secretly Odin's illegitimate daughter would have otherwise been quite a surprising twist the first time you play the game.
Outpost 2 was an early RTS with very sparse cutscenes, so at first glance, the backstory and campaign mission briefings seem sparse — more an Excuse Plot than anything else. Then you crack open the manual or on-disk manual and find detailed explanations of every unit, structure, and weapon, complete with a [very] short story centered around the structure, unit, or weapon, as well as plenty of backstory. Then you realize the game came with a novella on the CD as well, spinning two very different tales (one for each faction, which are very different) about the ongoing struggle to survive. Plymouth's ending in particular comes out of nowhere if you haven't been reading. If you're paying atention, the information (including the corresponding chapter of the novella) also appears in the campaign mode's mission briefings.
Overwatch has this quite badly. Although some of the massive story surrounding the world appears in the game, it appears mostly as easy to miss dialog or clues on the large and varied maps. Almost all of the story is contained in the shorts, trailers, in-universe news articles, and comics found on various other sites. The special event Uprising finally gave us some story in game, but alas, only for one particular Overwatch mission and it can be accessed only for a limited time.
The explanation for Alex Mercer's descent into villainy between [PROTOTYPE] and [PROTOTYPE 2] only exists in tie-in comics and is never explained in either game.
Psychonauts only recently got a complementary, developer-made Wiki, which you can find here. It also quenches some of the fan speculation, such as revealing the name of Razputin's father (Augustus, for you fanfic writers) and confirming the long fan speculation that Raz's last name is Aquato.
Puyo Puyo is a cross-series example. Much of the context behind Compile's characters (i.e. Why the Dark Prince is so determined to marry Arle or how Schezo got his dark powers) is only elaborated on in the Madou Monogatari series, both with the games themselves and the light novel tie-ins. However when SEGA obtained the rights of the Puyo Puyo IP and not Madou Monogatari, it became more of a zigzagging situation, where some details are still explicitly referenced (i.e. Witches being unnamed until they graduate), but other details are ignored or retconned. The Puyo Puyo games themselves also play it straight in the manuals and bios in supplementary materials, explaining details such as Puyo matches basically being elaborate wizard duels, by using a spell called Owanimo that causes four creatures of the same color to disappear.
Most of the information about the setting and monsters came from the "Famous Adventurer's Correspondence School" books included with the games. While for the most part this information wasn't necessary to complete the game (with the exception of the scientific formulae used as Copy Protection in Quest for Glory IV) it did a lot to flesh out the different kingdoms the Hero found himself in, and often provided useful information for dealing with monsters, general guidance on how each class was best played, examples on how spells or items could be used creatively to get the player to think outside the box, or the occasional hint about how certain situations or characters should be approached.
Almost the entirely of Katrina's and Erana's backstories weren't even in the manual. They weren't presented in full until many years after the series concluded, when co-creator Lori Cole posted them on her blog.
The Sierra adventure game Rama was (loosely) based on Arthur C. Clarke's second Rama novel. Despite there being some fairly major differences between the game and the novel, characters in the game will sometimes reference events that only happened in the book.
Rayman 3: Hoodlum Havoc contained several secrets that were only explained in the manual provided. Additionally, the game uses its manual in-game to break the fourth wall during the opening level by having the character Murphy instruct Rayman by reading to him from the game's manual, occasionally commenting on the manual's various illogicalities. The manual actually talks back!
A lot of Satoru's past in Remember11 is explained more thoroughly in a timeline that was released after the game.
In Rival Schools, the fighting portions of each game have introductions, cutscenes and endings that (for the most part) explain what's going on and the motivations behind most of the characters' actions. However, the Japan-only character creation modes in each game actually reveals even more background info about each character, as well as little known facets of their personalities (though none of it is required to understand the story). If you only play the games in English, you'd never guess Gentle Giant Boman is a fan of sunbathing, or Musical Assassin Yurika can identify a person by the sound of their footsteps.
Rune's backstory, Ragnar's upbringing in Wotankeld and more details on the story can be found in the game's manual.
Several details about characters in the Rune Factory games only come up in interviews and supplemental material, such as Ivan and Raguna's specific relation to the royal family, the fact that Iris is not human-though her actual species is not given, the Sharron can see the future-and also probably isn't human, or that all four dragons look the same as infants.
Runescape: A lot of the lore is buried in the website itself and the in game books. One example is the "Moonclan Manual". Most players believe magic comes from the runes the game is named for. But the Moonclan Manual states that they are more of a focusing tool to bring the energy inside the caster out, and it's possible (not in gameplay) to use magic without them.
Rides With Strangers doesn't have a manual, but the developers made several threads on Steam to flesh out each villain's backstory.
The Saints Row series has an interesting example. The manual for Saints Row hints at a plot point at the end of the game (and leading into Saints Row 2). How so? It's written from the perspective of an undercover cop, foreshadowing the fact that Troy is the undercover cop.
The Walking Dead: Saints & Sinners mostly avoids this trope, as it's a standalone plot in a fairly generic zombie apocalypse setting. However, the game does assume going in that players have at least a very basic understanding of The Walking Dead - specifically, that everyone in the setting is infected with a dormant form of the zombie virus, and will reanimate shortly after they die.
Sdorica has two novels, Before Sunset and After Sunset that tie into the first arc. The first book sets up the entire plot of the game, explains why Theodore is the Manipulative Bastard he is, and why Angelia could look up to and admire him. Needless to say it's a tragedy. The latter book is an Interquel about Nigel beginning to establish himself in Atlas, that also shows what happened to that city before and during its fall.
Shadow: War of Succession may have a rather generic Excuse Plot, but the manual does give last names and backgrounds to most of the fighters that the game rarely even hints at. (Viper is left as an unknown.) On the other hand, the Shadow King's real name- Kincaid Storm- is mentioned in the opening scene but not in the manual.
Shatterhand just shows a cut scene of him punching a robot. The manual lets you know that there is an army of them trying to Take Over the World, that Steve Herman lost his hands trying to stop two of them, that he now has robotic hands he uses to fight them, and that the game's title is his code name.
Shenzhen IO relies heavily on its manual, encouraging players to print and assemble a physical document organizer and refer to it while playing. It consists of 42 pages, including documentation for the game's assembly language, datasheets for the various in-game microchips, and snippets of example code. Story breadcrumbs—email correspondence, application forms, untranslated Chinese marginalia—are found throughout.
The manual for Sid Meier games, particularly the original Pirates, are loaded with historically-accurate details about the era you're playing, including Silver Train and Treasure Fleet routes, information on known pirates of the era, detailed notes on the cities, and commentary on the accuracy (or lack thereof) of the era's firearms! Pirates! used the historical data (ironically) as an anti-piracy technique. In the first game, you were asked about the routes of the Treasure Fleet and Silver Trains when arriving in port. In Pirates Gold, in your first confrontation with another ship, you would be shown a flag and asked to identify the famous pirate that it belonged to. These pirates, and their flags, were only ever shown in the manual. In either game, if you answer incorrectly, the game quickly becomes Unwinnable as you will never find any other ships at sea.
Additional information on the faction leaders' personalities, the backstory of the game before arriving on Planet, trivia on the planet and the solar system of Alpha Centauri is only found in the massive manual that came with the game.
The GURPS tabletop adaptation also includes many character details and snippets of the various factions' philosophies.
SimCity 2000's manual had many pages devoted to discussing city planning in reality. Much of it was useful to the game, giving you insight into the models used to create the simulation. Just as much of it was simply a love letter to city planning as a subject of research.
SimEarth's manual was over 500 pages, bound in a ring, and was larger than most modern game boxes. It explains the entire philosophy of the game as a "computer toy", the science behind the various models, and the equations for the atmospheric model are ALL IN THE MANUAL. It's quite impressive, but looking back, it was a bit of a wallbanger when they put CO2's greenhouse effect so high, practically ignoring the warming effects of nitrogen, oxygen, and water vapor, despite their completely saturated warming bands.
The various Sim X game manuals LOVED to provide massive amounts of information on the subject they were simulating. SimAnt 's manual was a couple of hundred pages long, but only 20-30 of those pages were about how to play the game; the rest of it was a small introductory textbook to the field of Myrmecology.
The two promotional comic books released before Sly 3: Honor Among Thieves benefit this trope. The first reveals How Sly, Bentley and Murray met in the orphanage and their first heist (for cookies, nonetheless), and how Sly met Carmelita (turns out that Sly was the one responsible for Carmelita becoming an inspector!). The second one starts right after the end of Sly 2: Band of Thieves with Sly seeing McSweeney in prison and learning about the Cooper Vault. Then Sly and Murray break Bentley out of the hospital, which was right after Murray leaves the gang. Some of the panels from the comic book are used as cutscenes for the games!
The manual for the second game, on the other hand, details the backstory of Constable Neyla, which is never revealed in the game. The manual makes note of her tendency to betray people- which turns out to be a key part of her character.
TheGenesisgames and Sonic the Hedgehog CD all have in depth plots, a well established world that focuses on ancient civilizations, and a Myth Arc that heavily foreshadows the events of Sonic Adventure. Unfortunately, all of this is exclusive to the Japanese manuals, which ultimately left English speaking audiences out of the loop for years.
According an official Sonic website, ZERO from Sonic Adventure is the "zeroth" E-Series robot with the official designation of E-100 Alpha.
According to several strategy guides, Project Shadow was meant to figure out a way to achieve Immortality, which the then-President of the United Federation wanted to use for war. Gerald Robotnik didn't want to be a part of it at first because he thought that it wasn't something that mankind needed, but changed his mind because Maria contracted a Soap Opera Disease that believed he could cure with the research.
The ARK was shut down because the GUN higher-ups did not trust Gerald or his research. When they heard about the violent tendencies of the Biolizard, they used it as a cover-up for their massacre of the personnel, placed the blame on Gerald, and forced him to continue working under their scrutiny before executing him. This is only explained in full in the Japanese version of the strategy guide.
Ever wonder why Sonic inexplicably turns into a werehog in Sonic Unleashed? The manual had the answer, the whole time.
"Dr. Eggman then, from the safety of his control panel, reversed the polarity of the Chaos Emeralds releasing the dark energy within. The energy was then fired as a powerful beam towards the world...Due to his proximity to the Chaos Emeralds as the dark energy was expelled, Sonic underwent a new transformation. His muscular density increased, his claws sharpened, his teeth grew into fangs and his body became covered with a lush heavy fur. Sonic had transformed into a Werehog."
Mary's origins and identity are left largely a mystery in the main game. However, the artbook included in the limited edition details her history. A small town, which would eventually become H City, was plagued by a curse. To suppress this, people were ritually sacrificed every fifty years, the first being a foreign girl with strong spiritual energy. Eventually, the Kujous created elaborate living dolls infused with spiritual energy to contain the curse, but the knowledge behind the dolls was lost in the war. One particular doll, resembling the foreign girl, was particularly powerful. When Mary awoke, she was fueled by the power of the curse she contained and the grudges of countless human sacrifices.
The spirit for the DLC sixth case of the game is only known as either Red Riding Hood or S-ko. The artbook provides her actual name: Sayoko Shiina.
A few details about the characters and story can only be found in their respective character profiles. Most notably, it goes into more detail about Satomi and Yuri, and how the former came to meet and conceive a child with Yakumo.
The Urashima Woman novella provides details about her past that aren't present in the story, along with providing a name and history for the midwife that killed her.
The games have a metric crapload of extra stuff ranging from novels ("Created by" Tom Clancy, with a negligible amount of help from his two sub-writers), secret-filled flash-websites, trailers, teasers, articles, spinoff-games, multiplayer campaigns(!), etc. The fourth game in the series was somewhat notorious for explaining the story (namely the manslaughter/murder of Sam's daughter, his short career in crime, subsequent imprisonment and the undercover infiltration of JBA. solely through preview articles and trailers.
How Sam Fisher went from being pardoned by the President at the end of Conviction to working for Fifth Echelon in Blacklist is only covered in the Echoes tie-in comic series.
Spoiler Alert comes with a prequel comic that explains where the enemies came from, and why Chilli Pepper Knight went out to kidnap the princess. This comic is only available when you purchase the Collector's Edition, though.
The first two Star Control games feature manuals with lengthy stories explaining the background of the Hierarchy Wars, each race's history, and what happened leading up to the beginning of Star Control II. In the case of the first game, it was arguably an Excuse Plot for a space strategy/combat game, in the case of the second game, most of the relevant information was available in-game if you ask enough of the right questions. And many vital plot points are only in the game, without the manual knowing anything about them.
Starcraft's manual mentioned the Great Offscreen War, the Guild Wars, and contained much of the game's backstory, playing a hand in the expansion pack's story (which barely contained any information in its manual, if it existed). The game itself assumes the player is already familiar with the histories and factions of the different races given there. There is no in-game exposition for even basic things, like who the Sons of Korhol or the Xel'Naga are or the Protoss caste system, which are all vital to even vaguely understanding the plot. It also explains why the Zerg need resources to build units.
Starcraft II turned the phenomenon up to eleven; all of the major characters, excepting those retained from the original, have backstories which are only explored in tie-in novels, though a brief summary of each character can be found on the official website.
This would have been the case with Starcraft: Ghost, had it not been cancelled after the novel Starcraft: Ghost: Nova came out, detailing Nova's background and how she came to be a Ghost (she happens to be the most powerful human telepath/telekinetic ever, able to mind-control others and emit TK blasts comparable to nukes; even Zerg!Kerrigan can't match her). Interestingly, the end of the novel has Nova joining the Ghost program, knowing that her memories will be erased, which kinda makes the novel irrelevant. The character of Nova is "revived" and used in Starcraft II, and an additional novel has been written about her exploits.
Star Trek Online's in-game manual, "The Road to 2409", only tells the story of how the Khitomer Accords were dissolved and the Federation and Klingons were at each others throats again. Star Trek Magazine, however, ends up showing information after that, such as the fate of Captain Data and the Enterprise-E ("Road" mentions that they disappeared while investigating something, Magazine reveals that they returned safe and sound, the E decommissioned and Data retiring to be a teacher) and the adventures of the newest ship to be christened Enterprise.
A certain code in StarTropics was revealed only by following an in-game character's cryptic suggestion to dip a certain document in water... the aforementioned document being an actual real document packaged with the game. Without the code, you can't progress. When it hit the Virtual Console, the loading screen showed the letter and code.
In the 1989 Famicom game, the manual explains Darth Vader's transformations are illusions like the Cave of Evil on Dagobah in The Empire Strikes Back.
The Dark Forces Saga's backstory for the protagonist was first given in the manual for the original game and was later contradicted by a trilogy of graphic novels. It was later revealed in an RPG supplement that the original manual were lies written by the agent who recruited him to make him seem more trustworthy.
The real name of the protagonist in The Force Unleashed is never given in the video game. He is for the most part referred to by his Code Name, "Starkiller", which many fans erroneously assumed to be his real name. The novelization based on the game, however, gives his real name as Galen Marek.
The web material for the John Woo game Stranglehold includes bios for all the major characters, such as the Captain with his authoritarian father, Jerry Ying and his estrangement from his straitlaced cop father, Dapang's background in child labor and underground death matches, and the bad guys' various criminal backgrounds. It also includes a tie-in to Hard Boiled, the movie this game is a sequel to, in Mr. James Wong's background, which mentions the involvement of his only son, Johnny, in arms running and his subsequent death in a certain hospital shootout.
The Street Fighter series is particularly notorious for this, with the most of the characters' backstories being published in Japanese only publications such as game specific special editions of Gamest Magazine or similar strategy guides/sourcebooks such as All About (insert game title/company here). It doesn't help matters that the English localizations of the early Street Fighter II and Alpha games had inaccurate translations (i.e: changing Cammy's past with Bison from subordinate to lover, Akuma being a demon or mass murderer, or the whole "You must defeat Sheng Long to stand a chance" thing, which launched much Fanon). Incidentally this plot doesn't resemble the one in the action movie at all.
The Shadaloo Combat Research Institute profiles on the Street Fighter V Character Encyclopedia website provides additional details for characters across the Street Fighter franchise.
Normally, the mostly-textless opening cutscene of Stretch Panic is utterly confusing and makes no sense. But with the multiple pages of story in the manual, it becomes...very confusing, making little sense. Given that it's a Treasure game, though, that's par for the course.
Parodying this trope, the manual of SubTerra contains a backstory that is not found in the actual game, but is also completely unrelated and irrelevant.
Suikoden IV's final boss is actually quite an appropriate end to the game, seeing as it's the ultimate source of all Rune Cannon ammunition, and its presence at Fort El-Eal was what allowed the Kooluk to make their giant Rune Cannon superweapon. Its destruction also means that no more Rune Cannons may be made, which is undeniably a Good Thing given how much trouble they've caused. Of course, since this is never addressed in the actual game, if you never read the backstory for the game (which is published separately), it just looks like a Giant Space Flea from Nowhere.
The wiki article of Super Charisma Bros clears up a lot of things that are never explained in-game - the events of Charisma 4 were actually a nightmare that Dudim had traveling through a time vortex, and that Dudim was sent back in time after the battle with Brynn due to "excess levels of Bazingonium."
Most of the official Super Mario Bros. games play this straight, where the functions of various characters, enemies and items are only covered in their instruction manuals. In the first game, the manual explains how the Koopa are a tribe of turtles, known for their black magic, who have used black magic to turn the mushroom people into stones, bricks and horse-hair plants, causing the Mushroom Kingdom to fall into ruin. The seven Mushroom Retainers, originally in the Princess' court, have been put under the spell of the Koopa turtle king. Magic Mushrooms, Fire Flowers, and the Starman don't just come from bricks, they have been turned into bricks, some invisible, and reward you with their power. You are told to kill members of the Turtle Tribe, including Little Goomba, a mushroom who betrayed the Mushrooom Kingdom, and Koopa Troopa, a soldier of the Turtle Empire. The Princess, the daughter of the Mushroom King, can undo the spell of the Koopa. That is why you must rescue her from Bowser, the sorcerer king.
In Super Mario Galaxy, there's the manual and game's tie-in trading card game. What makes the trading card game count is the fact that it revealed in its prologue the Magikoopa that attacked Mario when he is trying to save Peach when Bowser kidnaps her and carries her high up into space to be Kamek.
Super Mario World begins with Mario standing in a field and saying that he has to rescue Princess Toadstool because she was kidnapped while they were on vacation. Why they were on vacation (they were going to rest and recuperate directly after the events of Super Mario Bros. 3) and when she was kidnapped (when Mario and Luigi momentarily had their attention elsewhere) is only covered in the manual, as well as a better explanation of what Yoshi is and how the brothers reacted when they found the Yoshi egg. The Gameboy Advance version makes the story more clear by including an opening movie, showing they got distracted by the cape feathers and Peach was kidnapped in that time.
Even Super Mario Bros. 3 before that does not offer any sort of in-game explanation as to why the brothers go across seven kingdoms, how the Koopalings got the wands, and how the kings were turned into animals. As the manual explains, after Mario and Luigi brought peace to the Mushroom Kingdom, Bowser's seven children went on to make mischief in the peaceful Mushroom World. In the Mushroom World, connected to the Mushroom Kingdom, the seven kings of the seven worlds were turned into animals by their own wands when their wands were stolen by Bowser's kids. Both Toad and the Princess stay behind as Mario and Luigi begin their journey. Once again the Gameboy Advance remake adds clarity by adding an opening movie.
Super Robot Wars does this occasionally, but subverts it with Original Generation Gaiden, which takes most of the "Manual" from the Drama CD and OAV and puts it right in the game. It then played it straight anywhere with a separate drama CD for the "manual" game.
Furthermore, the only way that one can find out the actual names of the Special Attacks for all of the characters is by either reading the instruction manual (which is incomplete as it lacks certain characters) or visiting the aforementioned official website. This is averted for the original Super Smash Bros. 64, however, as animations accompanied by the Special Attack names are briefly shown at intervals when one reads the biographies found in the Data section.
Although Sword of the Stars gives you a fairly comprehensive info-dump on the in-game universe inside the game, reading the supplementary novel and following the game's forum provides a wealth of supplementary material. The game's story writer is a sci-fi novelist, and likes to frequent the game's forum to answer fluff questions from the fans.
Stars! has no real backstory to speak of, but the manual (and the help file) contains all of the statistics and math used to run the game, making the mechanics something almost possible to mathematically predict.
Tales of Vesperia has a lot of background information for characters as well as proper motivations for the enemies listed in an offshoot or two that never came over to America. What makes this a perplexing entry is that the Tales series of games are normally VERY good at including that sort of information and is usually one of the chieftain exemptions from this trope; which makes why they chose that route for this entry very questionable.
Team Fortress 2. In-game story? "You are one color team, kill the other color team". In various online comics and supplementary material? You see a grand tale of intrigue featuring two brothers who founded the aforementioned teams, an Australian man that's Testosterone Poisoning incarnate, a woman in purple controlling both sides and the long lost third brother and his army of robots, all revolving around a plan by the deceased father of the two brothers meant to punish them for their idiocy.
The instruction book for the original Teenage Mutant Ninja TurtlesNES game states that the Turtles' main mission in the game is to capture Shredder's Retromutagen Ray generator Life Transformer Gun, with which they can turn Splinter back to a human. This is why, at the end of the game, Splinter is restored to his human form; the game itself makes no mention of the transforming gun.
Done literally with Epyx's Temple of Apshai. The game simply shows the room number where the player is currently at ("ROOM: 23"), with a fully-detailed description given in the instruction manual.
The manual of Todd's Adventures in Slime World has Todd reading through a long series of Apocalyptic Logs left by previous explorers of Slime World.
While the series has an unusually high amount of dialogue and cutscenes for a shmup, that's really not saying much. Most actual information is in the character profiles, short stories, fanbooks, or spinoff manga.
Some of the side material managed to do this to itself. More specifically, the side-story Bougetsushou was split into three parts: the main story, Silent Sinner in Blue; a collection of character-focused vignettes, Cage in Lunatic Runagate; and a gag-manga, Inaba of the Earth and Inaba of the Moon. Inaba isn't really important to anything, but Runagate explains a few things that were glossed over in Silent Sinner. Also, it has the ending, and the explanation for why the whole thing happens that comes with it.
If you haven't played Second Opinion you wont know what Naomi and Little Guy are referencing when they are talking about not talking about their pasts. They're both ex-Delphi agents.
Second Opinion does this to itself - the climax of the main plot is glossed over so it can launch straight into the remake content and can be downright disappointing if one doesn't have access to Under The Knife to see the full version. It does close up some plot holes, though, such as how Delphi actually learned about Triti.
In addition to containing several hints, such as that antibiotic gel can be used to repel parasites, the manual to Second Opinion has a glossary explaining several medical terms used throughout the game.
Square Enix's "Ultimania" series. These monstrous manuals easily contain a hundred pages for a short book. Most of them are suitably doorstoppers and are packed with all of the information anyone could ever want about the game and its storyline. Unfortunately, it's all in Japanese so it is up to the kindness of fan translators for this information to be shared for a broader audience. It seems they packed so much information into the Ultimania Guides that they completely change the tone and course of the original story. Whether it makes the story more sensible or awkward is up to the reader, though none is allowed to question its canon level. Annoyingly enough for some people.
On a similar note, the Reunion Files book is essentially Ultimania for Final Fantasy VII: Advent Children. It further explains several plot elements, such as who the Remnants are and the fact that they're actually inadvertently undertaking Sephiroth's will, amongst other things. Mercifully, it's in both Japanese and English, and a lot more is covered in the more readily-available Advent Children Complete, but it's still annoying that it's only conventionally available in Japan.
The demo for Undertale included a 19-page instruction manual about the characters featured in the demo (being Flowey, Napstablook, and Toriel), how to attack, credits, and more. The page describing the enemy's turn is conveniently scribbled over. Another notable feature is the final page, which reads, 'a note from your friend.' It shows Flowey, smiling, introducing himself, looking forward to meet you in the game.
If the player chooses to play the True Pacifist Route, the final page changes to a note from Flowey that simply reads: "Don't get tot cocky."
If the player chooses the Neutral Route where they decide to kill Toriel, the final page changes to Flowey with an evil smile, laughing about how you decided to murder her.
If the player chooses the Genocide Route, almost every page changes to the last thing seen before the play quits the game, which is the Undertale title screen, and underneath it, it reads in red text: "That was fun. Let's finish the job." The last picture changes to a picture of Flowey without a face.
Valkyrie Profile has the Japanese-only Materials Collection, which contains tons of information about characters and settings. Since the game series is not as popular as, say, Final Fantasy, it has not been translated.
A lot of things that seem to come way, way out of left field in Vampire: The Masquerade Bloodlines are actually taken from the various Old World of Darkness source books. To the point where fans of the tabletop game will appreciate the many references, and everyone else blinks and tries to work out what the hell is up with the freakin' wereshark!
In the game Vexx, you have to collect a certain number of hearts in order to come to new worlds, one of these hearts is hidden inside a chest (which is itself inside a sort of whale), this chest has a lock on it that you can only open by inserting the right code by pressing buttons. It's possible to guess the right combination, but it becomes much easier with a hint in the manual, the description for the heart even tells you to "look in the book".
Most of the lore is found in the novels. Lord of the Clans is about Thrall's rise from a slave to the Warchief of the Horde, and is important to know why the Orcs went from being Always Chaotic Evil to Proud Warrior Race. Warcraft Adventures would have had that info apparently - they just canceled the game so it was all put in books. The backstory was later included (in summarized form) in World of Warcraft.
This is made glaringly obvious when certain characters or subplots become relevant to the main storyline, and suddenly some fully-developed characters will show up in World of Warcraft without their full backstory being given. Half of the story in the Sunwell Plateau dungeon, covering the adventures of Anveena Teague and Kalecgos, is only found in Warcraft: The Sunwell Trilogy, a manga series released several years before the dungeon. Anyone who did the dungeon without reading the book saw a few conversations between Kalecgos and a girl in a bubble who loved him without knowing that Anveena is the human embodiment of the energy of the destroyed Sunwell. It is why her "explosion" helps end the encounter.
Perhaps the most egregious example is the return of King Varian Wrynn. To sum up, since the game was first released, there had always been a long and involved questline involving finding out what happened to the missing king. This questline cut off suddenly at around level 30 with the capture of someone that might have some information, and a letter to the player saying that they would be called on again when the prisoner divulged his information. Fast-forward several years and the quest line was slightly expanded, only to dead-end again with no real conclusion. In Wrath of the Lich King, the king was suddenly back with (from the perspective of someone who doesn't follow the Expanded Universe) no explanation whatsoever. Why? Because they literally took a quest that had been left dangling in-game for four years and concluded it in the comic book series, in which the missing king is the main character.
The third expansion to the game, Cataclysm. Quite literally overnight, the whole world was altered completely. The leader of the Horde was suddenly Garrosh Hellscream instead of Thrall, Cairne Bloodhoof was Killed Off for Real and replaced by his son, Baine, and Magni Bronzebeard was effectively killed off and replaced by a council of three, including one of the Always Chaotic Evil Dark Iron clan. Little of this is ever actually explained in-game, and all of it takes place in the novel The Shattering.
Around this time, FandralStaghelm, the widely hated archdruid of the Alliance, suddenly gets replaced, and an early quest in Mount Hyjal in Cataclysm involves escorting him from his prison to prevent the Twilight Hammer cultists from breaking him out. The reason why he was imprisoned is revealed in the novel Stormrage. Xavius manipulated him into corrupting Teldrassil by using an image of his dead son, and when the image vanished and he essentially lost his son again, Fandral lost his sanity.
It gets even more complicated when including the RPG sourcebooks as legitimate sources of information. At least one piece of information is totally inaccurate (the death of Maiev in the sourcebooks was rendered obsolete when she showed up in Outland as a major plot point). This calls into question any assumption made based on the sourcebooks. Thankfully (or maybe not), a Q&A on the WoW forums revealed that the sourcebooks are officially not canon.
The instruction manual for the Vin Diesel video game Wheelman has massive amounts of this. The manual is written from the perspective of the Barcelona police, and gives much greater context to why the protagonist, Milo Burik, is in Barcelona in the first place. It also gives in-universe reasons for his skills and actions throughout the game (apparently, he just really wants to deface certain statues) and gives much more background information on the various criminal elements and friendly contacts that populate the city.
The PC game Where in the U.S.A. Is Carmen Sandiego? required you to look up information in Fodor's USA travel guide to get promoted. This was before the internet was in common use, so if you didn't have the book (which came with a new copy of the game), you'd have to guess what the largest export of New Mexico just happened to be. For the same reason, the Where in Time version came with an abridged encyclopedia, and the Where in the World version came with a copy of The World Almanac and Book of Facts.
the white chamber has an audio drama called "The Grey Tower" that serves as a prequel, filling out a lot of the backstory of the game and some of its mindscrewiness.
A companion volume to the Wild ARMs series reveals that, appearances to the contrary, they actually are directly related to each other — large time gaps and Filgaia's remarkable disaster-proneness obfuscates this, making most of the games appear to be largely unrelated stand-alone titles.
Several significant plot points in the Wing Commander series are, for various reasons, only mentioned in the game manuals. The manual for the X Box Live Arcade game Arena, "Star*Soldier", fleshes out the game in a way the then-limit of 50MB on game size didn't allow. (The limit was bumped to 150MB while Arena was in development.)
Wipeout, despite being a game about futuristic anti-gravity racing with little goal besides winning races, has a shocking amount of plot. With some filling in the gaps, official websites and manuals give almost a book's worth of backstory on the leagues, teams, and even a few people who aren't mentioned anywhere in the game's content.
In The World Ends with You, only the Japanese manual refers to the fact that the abilities of every Player is tied to at least one pin. Yes, this means that Mr. Mew is controlled (partially) via pin (it's called Groove Pawn, by the way). With one exception (Shiki making an offhand comment about Neku's ability to use more than one pin), this isn't discussed in the game itself.
World Neverland: Daily Life in Elnea Kingdom is the latest game in a long-running series, but the others were never release in English. So, much of the lore about the game's world isn't available in English. What is in the game is in the form of a massive optional In-Game Novel of backstory in the library.
The X-Universe has a history that goes back almost five billion years (Kardashev Type IVPrecursors are involved), of which the games through X3: Albion Prelude cover about forty. Various dribs and drabs of conflicting information on this backstory have come out of Egosoft over the years, until they finally decided to codify everything into an X-Encyclopedia packaged with the X-Superbox series collection. In addition to explaining the history and fleshing out much of the setting, it loves to talk about things that aren't even hinted at in the games, such as an independent human government called the Hatikvah Free League, and a race of Sapient Cetaceans on a hidden Boron planet.
A whole lot of the lore of Xenosaga, due to the series' scope being severely curtailed in mid-development. The series can be much better understood after reading the Xenosaga Perfect Guide.
Perfect Data of Ys contains a whole lot of interesting information about the world. The plotline for Ys SEVEN has been hinted at for at least a decade quite literally in manuals and the loading screen of Ys Eternal.