A game which takes place in or refers to another video game, but isn't really a sequel. It can be a simple side story, a PerspectiveFlip, or a chance to [[ADayInTheLimelight give a popular character background they didn't get in the original game]]. The major stipulation is it is not usually ''required'' to canonically fit into the main game or require having played it to enjoy. It also frequently (but not necessary) dips into GenreShift by being centred another type of core-gameplay than what is usual for the series.

Gaiden Games are sometimes titled from the direct translation of the Japanese word ''gaiden'', meaning "another story." Frequently, these games are released on portables or less-powerful systems, but modified appropriately. They are often lower budget and can be seen as cash-ins, but can be interesting if they choose a different viewpoint, poke fun at the original, or are simply more innovative than a large-budget game might be allowed to be.

Subtrope of SpinOff. Sister trope to PinballSpinoff. Also of note is that having Gaiden in its
title doesn't necessarily mean the game pertains to this trope. Even if you exclude ''VideoGame/NinjaGaiden'', which has a troubled approach with its ''gaiden'' status. See the respective entry below.


* ''VideoGame/MetalGearGhostBabel'' and the two ''VideoGame/MetalGearAcid'' games are officially recognize as "Gaiden" games in the ''Franchise/MetalGear'' series ([[http://game.watch.impress.co.jp/docs/20050917/mgs23.htm see here]]), even though they don't really fit in the series' canon in any way.
* ''Christmas [=NiGHTS=]'' is this for the ''VideoGame/NightsIntoDreams'' series. However, it was added onto the UpdatedRerelease released only in Japan for [=PS2=], and the American digital distribution release.
* ''VideoGame/WarriorsOrochi'' is a gaiden crossover between ''VideoGame/SamuraiWarriors'' and ''VideoGame/DynastyWarriors''.
* The ''VideoGame/VirtuaFighter'' series has ''Virtua Quest'' (released in Japan as ''Virtua Fighter: Cyber Generation''), a beat-em-up set in the {{Cyberspace}}. The original ''Virtua Fighter'' roster appears as ghost data that bestow their fighting techniques upon the player.

[[folder:Action Adventure]]
* The first three ''VideoGame/TombRaider'' games were eventually re-released as the "Tomb Raider Gold" series, and each game got its own Gaiden Game. [=TR1=] had Unfinished Business, [=TR2=] had Golden Mask and [=TR3=] had Lost Artifact.
** The downloadable game ''Lara Croft and the Guardian of Light'' seems to also be this, not taking place in the continuities of the original Core Design series or the Crystal Dynamics-developed games.
* ''VideoGame/GodOfWar: Chains of Olympus'' (a prequel to the original game)
* Every ''VideoGame/GrandTheftAuto'' game from GTA III to Vice City Stories was a Gaiden Game; they all took place in the same universe and had some recurring characters, but took place in three different decades (the Stories games took place a few years before Vice City and III) and locations. Other than a few characters who appear in multiple games, the storylines are completely unrelated and don't affect one another. ''VideoGame/GrandTheftAutoIV'' totally remakes the universe with a brand new Liberty City, though Vice City and San Andreas are confirmed to exist. ''VideoGame/GrandTheftAutoV'' in it's turn is a Gaiden Game for IV.
** There's also ''VideoGame/GrandTheftAutoAdvance'' for GBA that takes place before the events of [=GTA3=] and features some of the characters.
** The main reason for Vice City becoming a Gaiden Game (and thus initiating a sequence of Gaiden Games) is most likely because it was initially planned to be an expansion pack for GTA III instead of a Stand-Alone game, with early announcements in game magazines calling it "Grand Theft Auto III: Vice City".
* ''VideoGame/MafiaII'' is branded by most as a SpiritualSuccessor to the the first game, but it's technically a gaiden as it shares the same universe with the original Mafia in a similar fashion with GTA.
* ''VideoGame/MetalGearSolidPortableOps'' (taking place between ''VideoGame/MetalGearSolid3SnakeEater'' and ''VideoGame/MetalGearSolidPeaceWalker'') is unique in that while you don't have to play it to understand the story of ''Metal Gear'', it makes it easier to understand the story as the ending reveals how The Patriots where created, and fills in how the Philosophers became the Patriots. [[spoiler:They didn't.]] It also shows us that [[spoiler:[[NotQuiteDead Sokolov didn't die after all.]]]]
* In the ''Franchise/TheLegendOfZelda'' series, most major installments involve a new Link as protagonist, but there will often be a Gaiden Game to continue a specific Link's story, usually without any appearances by Princess Zelda, BigBad Ganon, or the Kingdom of Hyrule:
** ''[[VideoGame/TheLegendOfZeldaLinksAwakening Link's Awakening]]'' involves the Link from ''[[VideoGame/TheLegendOfZeldaALinkToThePast A Link to the Past]]'' waking up on a mysterious island during his travels. Later, a Creator/{{Capcom}}[=/=]Creator/{{Nintendo}} collaboration made the ''[[VideoGame/TheLegendOfZeldaOracleGames Oracle]]'' series as a midquel set between the two.
** ''[[VideoGame/TheLegendOfZeldaMajorasMask Majora's Mask]]'' has the Link from ''[[VideoGame/TheLegendOfZeldaOcarinaOfTime Ocarina of Time]]'', going to Termina after saving Hyrule. The game's working title was ''Zelda Gaiden''. It was supposed to be an add-on of sorts using the 64DD peripheral.
** ''[[VideoGame/TheLegendOfZeldaPhantomHourglass Phantom Hourglass]]'' is a side-game/sequel to ''[[VideoGame/TheLegendOfZeldaTheWindWaker The Wind Waker]]'', detailing one of Link's and Tetra's adventures during their quest to find a new land to settle.
** The ''[[VideoGame/TheLegendOfZeldaFourSwords Four]] [[VideoGame/TheLegendOfZeldaFourSwordsAdventures Swords]]'' [[VideoGame/TheLegendOfZeldaTheMinishCap trilogy]] was supposed to be made up of these, with their main villain being Vaati instead of Ganon, and then ''Four Swords Adventures'' [[HijackedByGanon shoehorned Ganon into the plot]] and connected it to the main series.
** In ''VideoGame/TheLegendOfZeldaTriForceHeroes'', the Link from ''[[VideoGame/TheLegendOfZeldaALinkBetweenWorlds A Link Between Worlds]]'' teams up with two {{Identical Stranger}}s to save a new princess in a new land. The game is rather DenserAndWackier than most ''Zelda'' titles.
** ''VideoGame/FreshlyPickedTinglesRosyRupeeland'' is either this or a spinoff, as the game stars recurring side character Tingle, with both Link and Zelda completely absent from the plot.
* The ''{{VideoGame/Yakuza}}'' series has ''Dead Souls'', which, as opposed to the main games which feature crime drama stories and brutal hand-to-hand fighting gameplay, takes place in the midst of a ZombieApocalypse and prominently features gunplay.
* The original ''VideoGame/NinjaGaiden'' trilogy for the NES, along with the arcade game released alongside the first NES installment, weren't actually side-stories to anything. In Japan, the series was originally known as ''Ninja Ryūkenden'' (Ninja Dragon Sword Legend). The use of "gaiden" in the English version is an example of GratuitousJapanese, since the developers were not sure how to localize the Japanese title ("Ninja Dragon" was considered one point, but Data East beat them to it with their beat-'em-up ''Bad Dudes vs. Dragon Ninja'', and a literal translation was considered to be [[OverlyLongName too long]]). With that cleared up, ''Ninja Gaiden Dragon Sword'' could be considered one to the Xbox series.
** Since the release of the ''VideoGame/DeadOrAlive'' series, and since the ''Ninja Gaiden'' titles are canonical to it, ''Ninja Gaiden'' can be considered a sidestory to ''Dead or Alive'' ([[SharedUniverse and vice versa]]).
* When Koji Igarashi took over as producer of the ''Franchise/{{Castlevania}}'' games (starting with 2002's ''VideoGame/CastlevaniaHarmonyOfDissonance''), he declared that the Nintendo 64 games ( ''VideoGame/{{Castlevania 64}}'' and its UpdatedRerelease ''VideoGame/CastlevaniaLegacyOfDarkness''), and ''VideoGame/CastlevaniaCircleOfTheMoon'' for the Game Boy Advance were side-stories to the main ''Castlevania'' storyline. The GameBoy game ''VideoGame/CastlevaniaLegends'' on the other hand, is no longer part of the canon.
** In Japan, ''VideoGame/CastlevaniaLegacyOfDarkness'' was titled ''Akumajō Dracula Mokushiroku Gaiden: Legend of Cornell'', making it a Gaiden Game to the earlier N64 title, whose Japanese title was ''Akumajō Dracula Mokushiroku''.
** The ''Boku Dracula-kun'' games for the Famicom and GameBoy (the latter brought over to the U.S. as ''Kid Dracula'') were never intended to be canon, though the BigBad, Galamoth, would later appear in the regular series.
* While not directly linked to another game, ''VideoGame/IndianaJonesAndTheFateOfAtlantis'' could be considered a Gaiden Game to the ''Franchise/IndianaJones'' series of movies.
* ''Franchise/ResidentEvil''
** ''VideoGame/ResidentEvilGaiden'' was the actual name of the game. Its ending has since been decanonized without doubt.
** The ''[[VideoGame/ResidentEvilGunSurvivor Gun Survivor'']] series could also count, though they have slightly more credible ties to the Canon. Some even seem to be retcon vehicles.
** ''VideoGame/ResidentEvil3Nemesis'' may be considered a gaiden to the second game. ''VideoGame/ResidentEvilOutbreak'' and its sequel are gaidens to both ''2'' and ''3''.
* ''VideoGame/DestroyAllHumans Big Willy Unleashed'' is a Gaiden Game in the ''Destroy All Humans!'' series.
* ''VideoGame/DevilMayCry 2'' is a two-disc set. The second disk, which you may think will extend the story, doesn't. It fits this trope by giving you a gaiden game in form of Lucia, letting you play as her for the parts of the story where she wasn't interacting with Dante. It makes little enough sense what she's doing that it could easily be considered a wholly different game played in the DMC format.
* The ''Franchise/{{Gundam}}'' anime franchise has quite a few Gaiden Games, most of which are spinoffs of [[Anime/MobileSuitGundam the original series]] and depict events that take place at the same time as White Base's adventures but in different parts of the world. The best-known of these include ''Rise from the Ashes'' (set in Australia), ''Blue Destiny'' (set in North America), and more recently ''Gundam 0081'' (which takes place between the original series and ''[[Anime/MobileSuitGundam0083StardustMemory Gundam 0083]]''). Some other games shift between this and a full-on LicensedGame - ''Zeonic Front'' and ''[[VideoGame/GundamVsSeries Federation vs. Zeon]]'' on UsefulNotes/PlayStation2 alternate between missions totally separated from the events of the anime and missions that put you right in the middle of major battles from the anime.
* ''VideoGame/PrinceOfPersiaTheForgottenSands'' is is [[TrilogyCreep the fourth installment]] in the ''Sands of Time'' series and an {{interquel}} between [[VideoGame/PrinceOfPersiaTheSandsOfTime the first]] and [[VideoGame/PrinceOfPersiaWarriorWithin the second]] but it's actually a standalone story. The events of the first game are mentioned once or twice and the forgotten sands are unrelated to the Sands of Time.

* ''VideoGame/MeltyBlood'', the rather popular 2D Fighter Gaiden Game to ''VisualNovel/{{Tsukihime}}'', which follows a plotline that didn't quite make it into the actual visual novel.
** Subverted when it basically became its own series.
* After the original ''VideoGame/GuiltyGear'', the following titles, ''Guilty Gear X'' and the ''Guilty Gear XX'' [[CapcomSequelStagnation installments]], were officially designated as sidestories like the novels, drama [=CDs=], and ''Guilty Gear Xtra'' manga, with ''Guilty Gear 2: Overture'' being touted as the "true" continuation of the first game's story. WordOfGod says they're still very much in-canon, with ''Accent Core Plus'' telling (part of) the story of how certain characters got to where they are [[TimeSkip by the time of]] ''Overture''.
* ''[[VideoGame/SoulSeries Soulcalibur II]]'''s Weapon Master Mode appears to be a gaiden storyline, as it takes place... somewhere other than Europe and Asia. Also, none of the ''Soul'' series characters appear in Weapon Master Mode; the characters in Weapon Master Mode use the fighters as "avatars," i.e. you're not actually fighting Mitsurugi, you're fighting some guy named Edgar. [[spoiler:Although there is a Lizardman named Calcos, aka Aeon Calcos who was transformed into Lizardman in the first ''Soulcalibur''.]] [[MindScrew Boy is this complicated.]]
** In ''Soulcalibur III'', it was a Euro-Asian conflict, by chance, happened to be in the areas where the characters looking for Soul Edge. [[spoiler:The king you worked for had it all along, and is batshit insane.]]
** Chronicles of the Sword is an AlternateUniverse, set on a fictitious continent with fictitious countries, and starring the Soul cast as mere cameos with no storyline relevance. It's not part of the main canon.
* ''Franchise/MortalKombat''[='s=] action games: ''VideoGame/MortalKombatMythologiesSubZero'', ''VideoGame/MortalKombatSpecialForces'' (starring Jax), and the more recent ''VideoGame/MortalKombatShaolinMonks'' with Liu Kang and Kung Lao. ''Mythologies'' serves as a distant prequel to the events of ''VideoGame/MortalKombat4'' while also setting up the elder Sub-Zero's [[ArchEnemy enmity with Scorpion]] and [[spoiler:eventual transformation into Noob Saibot]], whereas ''Shaolin Monks'' is a BroadStrokes retelling of [[VideoGame/MortalKombat1 the first]] [[VideoGame/MortalKombat2 two games]] with a noticeable changes to the narrative (though ''VideoGame/MortalKombat9'' makes a nod or two its way all the same). No one likes to talk about ''Special Forces'', but it was eventually and definitely rendered [[CanonDiscontinuity officially non-canon]] by ''VideoGame/MortalKombatX'' and its corresponding comics.
** Also the Konquest Mode from ''[[VideoGame/MortalKombat Deception]]'', which starts 50 years before the main game's story and ends in the beginning of ''Deception'', and shows the story of one of the characters' exploits while [[spoiler:unknowingly serving the BigBad's personal agenda]].
* The first ''VideoGame/StreetFighterEX'' originally had the WorkingTitle ''Street Fighter Gaiden'' and the plot of the ''EX'' series (what little it has) is considered a side-story to ''VideoGame/StreetFighterAlpha'' and/or ''VideoGame/StreetFighterII''.
** ''VideoGame/StreetFighterOnlineMouseGeneration'' is a one-off game in the series that has no connection to the main series.
* Despite being a small series (in terms of the number of entries, at least), ''VideoGame/PunchOut'' has one of these: ''Arm Wrestling''. It used the same two-screen arcade cabinet style of the original 2 games, its art style was similar to the ''VideoGame/PunchOut'' series at the time, the main character resembled the arcade version of Little Mac (who had green hair), and arm wrestler Mask X, once his titular mask is removed, is revealed to be [[spoiler:Bald Bull]].

[[folder:First-Person Shooter]]
* ''VideoGame/UnrealTournament'' is a Gaiden Series to the ''VideoGame/{{Unreal}}'' series, taking place within the Unreal universe but having little to do with the Skaarj invasion.
** And the ''[[VideoGame/UnrealTournament2004 Unreal Championship]]'' games for consoles are a spinoff from ''Unreal Tournament'', creating a Gaiden Game of a Gaiden Game.
** ''VideoGame/UnrealTournamentIII'' could be considered a Gaiden Game for the rest of the ''UT'' games - it still plays like they do, but it actually has a storyline beyond "[[ToBeAMaster become the Champion]]" and as such might be the closest we'll have to an actual ''Unreal 3''.
* ''Franchise/{{Halo}}'':
** ''VideoGame/Halo3ODST''; despite that ''3'' in the title (and being based off ''VideoGame/{{Halo 3}}''[='s=] engine), it actually takes place during ''VideoGame/{{Halo 2}}'', and involves an almost totally different cast of characters. The reason why it has that ''3'' in its title is because it was originally planned to be merely an add-on that still required ''Halo 3'' to play. But as the game grew and grew and more and more tweaks to the game engine were made[[note]]the VISR system, the whole NAV/map/waypoint system, Firefight game mode, making groups of opponents patrol and thus successfully navigate large areas, and so on[[/note]], Bungie decided to make it a stand-alone product for half the price of a normal retail game. Then Microsoft "interfered" and added a second disk containing the multiplayer portion from ''Halo 3'' along with all the DLC map packs, and upped the price to that of a normal retail game.
** ''VideoGame/HaloReach'' is a side story prequel to ''VideoGame/HaloCombatEvolved'' that takes place concurrently with the latter parts of ''Literature/HaloTheFallOfReach''. This one is a downplayed example, as Bungie treated ''Reach'' more like a full entry in the series instead of an expansion, and its game mechanics are much closer to the other Halo shooter games.
* Most of ''VideoGame/MedalOfHonorFrontline'', except for the D-Day prologue, is set in between the third and fourth missions of the original game. ''[[VideoGame/MedalOfHonorAlliedAssault Allied Assault]]'' also has a few {{continuity nod}}s to that.
* ''VideoGame/CallOfDuty 4: VideoGame/ModernWarfare'' for the UsefulNotes/NintendoDS, in relation to the versions released on UsefulNotes/XBox360, PC, and UsefulNotes/{{PS3}}. The game features similar missions, but featuring characters from other teams operating either in parallel or in support of the teams from the main release. Every "main" release in the series has since been followed by a handheld, mobile, and/or, in one case, [[UsefulNotes/PlayStation2 last-gen version]] that acts as a side-story to the main game; the aforementioned last-gen version, for ''World at War'', is notable in that it and the DS version both included a British campaign like every other UsefulNotes/WorldWarII-based game in the series had, whereas the 360, [=PS3=], and PC version had its British campaign and associated assets cut.
* The second ExpansionPack for ''VideoGame/FirstEncounterAssaultRecon'' is this for both the original game and its first expansion pack, starting within the last hour or so of the original game and ending before the first expansion does.
* ''VideoGame/MetroidPrimeHunters'' is connected to the ''VideoGame/MetroidPrimeTrilogy'' (itself a Gaiden interquel between ''VideoGame/{{Metroid 1}}'' and ''VideoGame/MetroidIIReturnOfSamus'') since it takes place between ''VideoGame/MetroidPrime'' and ''VideoGame/MetroidPrime2Echoes'', but that's where the connections end. While the ''Prime'' series focuses on recurring element, Phazon, Hunters does not use or reference Phazon at all, but the story focuses on Samus and a bunch of other bounty hunters all fighting each other for a rumored absolute power contained somewhere in the galaxy. The game focuses a lot more on the online multiplayer as well, whereas the ''Prime'' trilogy only used multiplayer once (local, no online) and it was a side thing instead of a main attraction.
* Players of ''VideoGame/DustFiveOneFour'' take the role of ground-based mercenaries in the ''VideoGame/EVEOnline'' universe. EVE players can hire Dust players to seize or defend planetary facilities for them, and provide [[OrbitalBombardment air]][[https://www.youtube.com/watch?v=45mlVuLs_Nw strikes]]
* Though chronologically a sequel, ''VideoGame/{{Bioshock 2}}'' qualifies as the game is from the perspective of a [[HumongousMecha Big]] [[PoweredArmor Daddy]], specifically a prototype named Delta. The gameplay is similar, but the mechanics and weaponry are modified slightly to give the feel of controlling one, and you also have a relationship with [[CreepyChild Little Sisters]] similar to that of the Big Daddies themselves. The storyline also give some additional insight into the concept and technology of the Big Daddies as well.

[[folder:Open Sandbox]]
* ''VideoGame/DeadRising2'' focuses on Chuck Green, who's trying to survive a [[ZombieApocalypse zombie outbreak]] in Fortune City Nevada, and keep his daughter from becoming a zombie. ''Dead Rising 2: Off the Record'' is this, as the main character is Frank West, TheHero from the first ''VideoGame/DeadRising'', and this version includes several new [[NonPlayerCharacter survivors]] and [[BossFight psychopaths,]] more weapons combinations, the ability to collect money from busted slot machines (in the original, slot machines could be broken, but they did not give any money), a new zone making the map bigger than in the original game, as well as new plot twists, (here [[spoiler: [[SparedByTheAdaptation Rebecca Chang is only wounded]] and the villain is [[EvilAllAlong the leader]] of [[ZombieAdvocate C.U.R.E.]]]])

* There's a couple in the ''Franchise/SonicTheHedgehog'' series. ''VideoGame/TailsAdventure'' springs to mind. In the Japanese manual its said to take place before Tails' fateful meeting with [[HeterosexualLifePartners his iconic partner in crime fighting]]. In the Western version it's treated as a BusMansHoliday but in both, its still Tails's [[ADayInTheLimelight day in the limelight.]]
** There's also ''VideoGame/SonicBattle'' and the two games from the ''VideoGame/SonicStorybookSeries'' (''Secret Rings'' and ''Black Knight'').
* Each ''VideoGame/DonkeyKongCountry'' game has a Game Boy follow-up in the ''Donkey Kong Land'' series. The first is a completely separate adventure, the second is basically a port of ''VideoGame/DonkeyKongCountry2DiddysKongQuest'' and the third is a basic collection of very generic levels in the style of ''VideoGame/DonkeyKongCountry3DixieKongsDoubleTrouble''.
* ''VideoGame/{{Daxter}}'' takes place before the main events of ''VideoGame/JakIIRenegade''. The game is ADayInTheLimelight for the sidekick, Daxter, without Jak having a playable role.
* ''VideoGame/RatchetAndClankSizeMatters'' and ''VideoGame/SecretAgentClank'' have their settings unconfirmed, but known to be after the third game. However, their canon status is disrupted, and are completely [[{{CanonDiscontinuity}} ignored]] by Creator/InsomniacGames.
* ''VideoGame/{{Portal}}'' is almost an [[InvertedTrope inverted example]]; everything (bar a couple of throwaway references to Black Mesa) was original, and the connections to the ''VideoGame/HalfLife'' story were made in the main ''Half-Life'' series.
** ''Blue Shift'', ''Opposing Force'' and ''Decay'' could probably also be considered Gaiden Games. Especially ''Opposing Force'', which while set in the same time-frame as the original, introduced new aliens (Race X) and characters (Cpl. Adrian Shepard, Security guard Otis Laurey) that have not been considered "canonical" by Valve.
* ''Trilby: VideoGame/TheArtOfTheft'' is Yahtzee's Gaiden Game for the VideoGame/ChzoMythos series, featuring as it does one of the main characters years before the series proper starts, and an UnexpectedGameplayChange to stealth platforming.
* Back in the 1990's many PC and Amiga titles were made into a ChristmasSpecial Gaiden Game, usually released in some gaming magazine's cover disk as a present for fans. The games that got this treatment included ''VideoGame/CannonFodder'', ''VideoGame/{{Dizzy}}'', ''VideoGame/FireAndIce'' (coverdisk for the Christmas 1992 issue of ''Magazine/AmigaPower''), ''VideoGame/{{Lemmings}}'' and ''VideoGame/JazzJackrabbit'' (the latter of which actually got two separate Christmas editions, the 1994 "Xmas Edition" and the 1995 "Holiday Hare"). This also happened in the 1980s with ''Moley Christmas'', a ''VideoGame/MontyMole'' game exclusively distributed with a UsefulNotes/ZXSpectrum magazine with a self-referential plot.
* ''VideoGame/GargoylesQuest'' has the Japanese title ''Red Arremer: Makaimura Gaiden''; it is a spinoff of ''VideoGame/GhostsNGoblins'', or ''Makaimura'' in Japan.
* ''Shift Freedom'', which has the same mechanic as the main ''VideoGame/{{Shift}}'' series, but does not appear to be part of that story.
* ''VideoGame/SuperMarioLand'' and ''VideoGame/SuperMarioLand2SixGoldenCoins'' share the same basic platforming elements like Franchise/SuperMarioBros, but take some liberties with the story, settings and items. Instead of rescuing Peach from Bowser like usual, Mario takes a trip to a neighbour country of the Mushroom Kingdom to save a different princess from an evil alien in the first game. In the sequel, Mario has to take back his private island from his evil counterpart, Wario. The [[VideoGame/WarioLandSuperMarioLand3 third game]] distances itself completely from Mario and gives birth to the ''VideoGame/WarioLand'' series instead. Notably, none of the games were designed by Creator/ShigeruMiyamoto, but were well-received nonetheless.

* The ''VideoGame/{{DJ MAX}}'' series has primarily been a ''VideoGame/{{beatmania}}''-like game, but the newly-released arcade game ''DJ MAX Technika'' is a much different game, with touchscreen-based gameplay combining elements of ''VideoGame/OsuTatakaeOuendan'', ''VideoGame/EliteBeatAgents'', and ''VideoGame/{{Lumines}}''. Due to its similarities to the former and its harsh LifeMeter, it's a very NintendoHard game; you can easily fail a song in the first 10 seconds.

[[folder:Real Time Strategy]]
* ''VideoGame/HaloWars'' is a RealTimeStrategy spin-off/prequel to the main ''Franchise/{{Halo}}'' series.
** In contrast, its sequel, ''VideoGame/HaloWars2'', takes place ''after'' ''VideoGame/Halo5Guardians''.
* ''VideoGame/YggdraUnison'' is a gaiden game to ''VideoGame/YggdraUnion''; it allows the player to command any army, make any alliances he or she wants, and aim for world domination in a WideOpenSandbox style of play. The game is considerably more lighthearted than its canon counterpart, and concentrates on character development and interaction over story.

* ''Franchise/ShinMegamiTensei'':
** ''VideoGame/ShinMegamiTenseiIf'' started off originally as a gaiden game of sorts in the SMT universe, taking place just before ''VideoGame/ShinMegamiTenseiI''. It later became canon when the protagonist appeared in ''VideoGame/{{Persona}}'' and ''VideoGame/Persona2'', and started the IntercontinuityCrossover that occurs throughout the Megaten franchise.
** ''VideoGame/ShinMegamiTenseiStrangeJourney'' may sort of count; despite the fact that it was originally meant to be the fourth game in the main series, it doesn't have a clear-cut connection with the previous three entries (which themselves were pretty closely linked together); Amusingly enough, it turned out that the ''actual'' ''VideoGame/ShinMegamiTenseiIV'' isn't all that connected to the other main series games either[[note]]WordOfGod actually stated that the prerequisite for an SMT game to be considered part of the main series is for it to "occur in Tokyo". Strange Journey, despise being a strong constestant for the 4th title, instead got branded as a Gaiden Game exactly because it doesn't happen anywhere remotely close to Japan. Which wasn't the case for SMTIV[[/note]].
** There are more spinoff games than there are main series games. Hell, there are more games in the ''[[Franchise/ShinMegamiTenseiPersona Persona]]'' series [[CashCowFranchise than in the main series.]] There are even ''Persona'' spinoffs (a spinoff ''of'' a spinoff,) including a browser-based RPG, and a long series of cell phone games based on ''VideoGame/Persona3'' (including one focusing on [[RobotGirl Aigis]] 10 years before the start of the game).
* ''VideoGame/SailorMoonAnotherStory'' was not so much a franchise distancer as a nod that it is not canonical to the ''Anime/SailorMoon'' mythos in very BroadStrokes.
** Much the same is true of ''Manga/{{Dragonball}} Z Gaiden: Plan to Eliminate the Saiyans''. Its story has no bearing on the manga or anime, though Toei did produce a companion {{OVA}}.
** As well as ''VideoGame/ZoidsLegacy'', which is like a MegaCrossover {{fanfic}} of all the series continuums in video game form.
* ''VideoGame/FinalFantasyX2'' orginally was informally referred to as a Gaiden Game before being treated as a direct sequel. Largely existing as an exercise in producing a sequel and light-hearted enough to occasionally take the piss out of its premise and characters, it was mainly dismissed in the West for being much sillier than its predecessor, and for deviating too much from the Final Fantasy formula.
** Even before ''X-2'', the developers weren't sure if ''VideoGame/FinalFantasyIX'' would be considered part of the main franchise due to how much is deviated from ''VideoGame/FinalFantasyVII'' and ''VideoGame/FinalFantasyVIII''; it was less than a year before release that Square officially called it ''IX''.
** The spinoff games to the ''VII'' universe could be considered Gaiden Games, including the [=PS2=] sequel ''VideoGame/DirgeOfCerberus'', and two prequels, ''VideoGame/BeforeCrisis'' for mobile phones and ''VideoGame/CrisisCore'' on the PSP. Fans are divided how much material has been stapled on as a cash grab and how much was simply cut for time.
* ''VideoGame/GalaxyAngel EX'' is a non-canonical glorified giant minigame.
* It could be argued that ''VideoGame/{{Xenosaga}} 2'' and ''3'' were Gaiden Games, not to ''Xenosaga'', but rather to ''VideoGame/{{Xenogears}}''. There's a lot of legal difficulties in the connections between those, so just look at the ''Xenosaga'' article on Wiki/TheOtherWiki to learn more about the connections (and lack thereof).
* ''VideoGame/PhantasyStar Gaiden'' was originally intended to fill in some side events to the series to act as the lead-in to an earlier concept for ''Phantasy Star 4''. As that game ended up using a different storyline in the final version, and there hasn't been a single game released in that continuity since, said Gaiden is now [[LeftHanging meaningless to the overall continuity.]]
* Many gaidens are found in the ''Franchise/MegaMan'' franchise -- in fact, each series seems to get at least one. Typical examples are ''VideoGame/MegaManAndBass'', ''VideoGame/MegaManXCommandMission'', ''VideoGame/MegaManLegends'' and ''The Misadventures of Tron Bonne'', and ''VideoGame/MegaManBattleNetwork: Battle Chip Challenge''.
* The first two ''VideoGame/ShiningForce Gaiden'' games (Game Gear) were eventually bundled under the name ''Shining Force CD'' (Sega CD). And just to be confusing, ''Shining Force Gaiden III: Final Conflict'' is unrelated to the previous two Gaidens (aside from being on Game Gear) and is instead a bridge taking place between the first two 'proper' ''Shining Force'' games.
* The handheld titles of the ''VideoGame/KingdomHearts'' series are frequently considered Gaiden Games to the "main" series, perhaps because of their tendency towards {{Word Salad Title}}s and the fact that they're on handhelds, rather than consoles. This is not the case; these games are all full installments of the series which build upon the story of the games and lead directly into the next "main" game. ''Kingdom Hearts II'' makes more sense if you've played ''Chain of Memories'' and the games released after ''Kingdom Hearts II'' are ''quite clearly'' building up to a climax that will be resolved in the future ''Kingdom Hearts III''.
** Played straight with ''VideoGame/KingdomHeartsCoded'' to a degree. The main purpose of the game is to reveal the content of [[SequelHook the letter written by Mickey to Sora]] at the end of ''Kingdom Hearts II'' and how Mickey found out about the fate of Aqua, Terra and Ventus, [[InternalReveal something the player already knows]] if he played to ''Birth By Sleep'' previously. Most of the actual plot (Mickey creating a data Sora to restore Jimminy's journal by defeating bugs) has little bearing on the MythArc and is never alluded in the next game ''Dream Drop Distance''. It does contain a few relevant points that are obviously setting up for future games though, including the first mention of the Book of Prophecy; Maleficent and Pete gaining knowledge of such a thing; and Mickey seeing all the people Sora has to help which includes Xion, a character he previously would have had no reason to be aware of at all, and that fans may have expected not to see again.
* The GBA remake of ''VideoGame/FinalFantasyII'' contained a short quest after beating the game, detailing what happened to all the dead party members after they died.
* ''VideoGame/SuperRobotWars'':
** There are three Gaiden games with each of them a part of the three major continuties ("Classic", [[VideoGame/SuperRobotWarsAlpha Alpha]], and [[VideoGame/SuperRobotWarsOriginalGeneration Original Generation]]). The first Gaiden game ''[[VideoGame/SuperRobotWarsGaiden Super Robot Wars Gaiden: Lord of Elementals]]'' told of the origins of the Masou Kishin characters, a group of [[OriginalGeneration Banpresto-created originals not seen anywhere else]]. ''Super Robot Wars Alpha Gaiden'' focused on TimeTravel and wasn't necessary for players to enjoy the previous Alpha game (most likely because Banpresto wanted an excuse to show off obscure mecha series, since it was full of them). ''Super Robot Wars Original Generation Gaiden'' fits this trope because it was shorter than the average [=SRW=], including several extras such as a battle viewer and a card game. It's also downplayed, though, since all three are essentially ''sequels'' that happen to have the word "gaiden" in their name. ''VideoGame/SuperRobotWarsAlpha'' depends on the player having some foreknowledge of the events set in ''VideoGame/SuperRobotWarsEX'' or ''VideoGame/SuperRobotWarsGaiden'' for background on the Masou Kishin characters, otherwise one can get too confused at the references they make to Alpha's back story. ''Alpha Gaiden'' is heavily referenced in the proper sequel ''Alpha 2'', where the [[Manga/GetterRobo Dinosaur Empire]] is defeated for the third time, and the finale ''Alpha 3'' assumes the player knows of Sanger Zonvolt's role at the Earth Cradle, despite the fact it was supposed to be highly secretive. Hell, the fact the [[Anime/MobileSuitZetaGundam Titans]] are more or less liberally screwed and [[Anime/MobileSuitGundam Char Anzable's]] disillusionment with humanity DEPENDS on the events of Alpha Gaiden. In short, Banpresto's definition of "gaiden" means a game that provides story details bridging the gap and answering the EpilepticTrees present in the other games in continuity. In fact, there's very little an "Original Generation 3" couldn't reference the events of ''Original Generation Gaiden'', considering both the effects on existing characters and all the {{EarlyBirdCameo}}es present in that game.
** '[[VideoGame/EndlessFrontier Super Robot Wars OG Saga: Endless Frontier]]''. While a spin-off, the back-story establishes the events in Original Generation continuity ultimately influenced the entirety of Endless Frontier. Its sequel ''Endless Frontier EXCEED'' even manages to rope in characters ''from'' the main Original Generation games.
** Amusingly, a remake of the original ''Super Robot Wars Gaiden'' has been announced, only it now carries the "OG Saga" subtitle instead. Thus, the name "Gaiden" has become reserved for half-sequels while "OG Saga" is given to the actual Gaiden Games.
* ''VideoGame/ChronoCross'' is somewhat of a Gaiden Game for ''VideoGame/ChronoTrigger'', being set 10 years after the "present" time in the latter and retaining only a handful of characters, all of whom show up in three scenes or fewer. What really makes it gaiden, though, is the fact that, in the end, the entire point of the story is to resolve a hanging plot thread from its predecessor (see UrbanLegendOfZelda). ''Radical Dreamers'' was a Japan-only text adventure Gaiden Game to ''Chrono Trigger'' released on the SNES' Satellaview addon. It was later overhauled, greatly expanded, turned into a proper RPG... and became ''Chrono Cross''.
* The ''Worlds of Ultima'' series were Gaiden Game's taking the fantasy-based Ultima VI engine (and main character) to other settings, such as Mars. ''Ultima Underworld'' was also a Gaiden Game, being a side story set in the main Ultima world, because its plot directly bridged ''Ultima VII'' and ''Ultima VII Part 2'' (in fact, in the latter the PC starts with a quest item obtained in [=UU2=] with no in-game explanation of where it came from). There are also the two console games from the mid 90s, ''Ultima: Runes of Virtue'' and ''Ultima: ROV 2''. Both games are set in the usual Ultima game world, and feature characters and towns familiar from the parent series. But both games are more like action games than [=RPG=]s, and neither one is part of the official Ultima chronology. They are, like ''Underworld'', a separate mini-series of their own.
* There are two Japan-only games in the ''VideoGame/{{Suikoden}}'' series called, quite simply, ''Suikogaiden volumes 1 and 2''. These games are basically side-stories featuring a previously-unknown character from Harmonia named Nash Latkje (who would later appear as a Star of Destiny in ''VideoGame/SuikodenIII''). The two games take place around the time of ''Suikoden II'', the first starting before and during [[VideoGame/SuikodenII SII]], and the second taking place shortly after the end of [[VideoGame/SuikodenII SII]]. In both games, Nash interacts with various characters from ''VideoGame/SuikodenII'', giving more perspective on many of the lesser-known characters. Lastly, ''[[VideoGame/SuikodenTactics Suikoden Tactics/Rhapsodia]]'' is another example, set just after ''VideoGame/SuikodenIV''.
* ''Franchise/TheElderScrolls'': In addition to its main series of WideOpenSandbox WesternRPG style games, the franchise includes several other games which take place in the same world and are generally treated as canon, but offer different experiences from the main series. To note:
** ''An Elder Scrolls Legend: Battlespire'' is an action-oriented DungeonCrawler with downplayed RPG mechanics. Originally planned as an expansion to ''[[VideoGame/TheElderScrollsIIDaggerfall Daggerfall]]'', it was released as a stand-alone game and takes place during the time frame of ''[[VideoGame/TheElderScrollsArena Arena]]''. The Battlespire, a WizardingSchool for Imperial [[MagicKnight Battlemages]], comes under attack by the forces of [[DestroyerDeity Mehrunes Dagon]], who seek to use it as a conduit for invading Tamriel. A single student (the PC), must fight through the Battlespire to defeat Dagon and [[ItsPersonal free their partner]]. A good chunk of the information of the things known about the [[OurGodsAreDifferent Daedra]] originates in this game.
** ''The Elder Scrolls Adventures: Redguard'' is a spin-off ActionAdventure game with very few RPG elements. Some 400 years before ''Arena'', a Redguard by the name of Cyrus travels home to find his sister missing and himself embroiled in a web of political intrigue. It was well received by critics and fans, but due to the cost of production and being built on outdated technology, it was a financial flop. The ''Pocket Guide to the Empire'', [[{{Feelies}} which came with the game]], gave one of the first comprehensive looks at the series' [[{{Backstory}} background lore]], which would be greatly expanded on in future games.
** Another ''The Elder Scrolls Adventures'' game, ''The Eye of Argonia'' was planned but never made, though the Eye itself is mentioned in the main series. (Those who don't know this often erroneously assume that it's a reference to ''Literature/TheEyeOfArgon''.)
** The ''Elder Scrolls Travels'' is a side-series of small, mobile phone games developed for Java-enabled devices, including the UsefulNotes/NGage. ''Travels'' consists of ''Dawnstar'', ''Stormhold'', and ''Shadowkey'', with the canonicity of each [[CanonDiscontinuity unclear at best]].
** ''VideoGame/TheElderScrollsOnline'' is an {{MMORPG}} prequel of the main series, set roughly 500 years prior the events of ''Arena''.
* ''EverQuest Online Adventures'' takes place 500 years before the first ''VideoGame/{{Everquest}}''. ''Lords of EverQuest'' is an [[RealTimeStrategy RTS]]. ''Champions of Norrath'' and ''Champions: Return to Arms'' are action games set in the [=EverQuest=] universe. The Pocket PC games ''Hero's Call'', ''Hero's Call 2'' and ''War On Faydwer'' share some thematic connections to the main games.
* The ''VideoGame/DeusEx'' GameMod ''VideoGame/{{Zodiac}}'' has JC Denton's brother Paul Denton investigate a separate conspiracy.
* The Enhanced Edition of ''VideoGame/TheWitcher'' has two additional stories named 'Side Effects' and 'The Price of Neutrality', which are completely unrelated to the main game, but feature locations and characters known from there.
* ''VideoGame/BarkleyShutUpAndJamGaiden'': A spinoff RPG from the original sports game ''Barkley: Shut up and Jam!'' There's also that ''Film/SpaceJam'' is also part of the game's canon.
* ''Franchise/{{Pokemon}}'' has had a bunch of side games. An incomplete list: the FirstPersonSnapshooter game ''VideoGame/PokemonSnap''; the PuzzleGame ''Pokemon Trozei!''; and the ''VideoGame/PokemonMysteryDungeon'' and ''VideoGame/PokemonRanger'' series. Likewise, the main series games are all Gaiden Games of each other, with references and allusions but no actual interaction. Mystery Dungeon & Ranger also have references and allusions but no interactions to their own series', so gaiden games that are gaiden games of each other...
* ''VideoGame/BreathOfFireIV'' has had a minor constellation of Gaiden Game treatments--at least two of them being released (along with a ComicBookAdaptation of ''IV'') fully [[FleetingDemographicRule seven years after the original release]]. These last two, ''Breath of Fire IV - The Sword of Flame & the Magic of Wind'' and ''Breath of Fire IV: Faeries Light Key'', are two separate side-stories of ''IV''. There's also a spinoff of the fishing minigame from ''IV'' as well as a "Great Dalmuti"/"Millionaire" game featuring characters from ''IV''. Unfortunately, due to the platform these were released on (Qualcomm's BREW OS, which is only common in Japan) these are likely to remain NoExportForYou permanently--much to the vexation of the English-speaking ''IV'' fandom.
* The ''VideoGame/FrontMission'' spin-off ''Gun Hazard'' is not only a side-scrolling shooter, but also takes place in its own alternate universe.
* ''VideoGame/NieR'' is one of ''VideoGame/{{Drakengard}}'', with the former taking place after the most bizarre ending of the latter (Caim and Angelus chase an EldritchAbomination into modern day Tokyo and and after defeating it are blown to hell by fighter jets). Drakengard's joke ending becomes [[CerebusRetcon very serious]] for Nier. [[spoiler: Caim, Angelus, and their quarry brought magic into the real world... and magical diseases like [[DepopulationBomb White Chlorination Syndrome]] [[ApocalypseHow against which a world without magic had no defense]]...]]
* ''VideoGame/ValkyriaChroniclesIII'' is a Gaiden Game to the original ''VideoGame/ValkyriaChronicles''. It takes place during the same time frame from the perspective of a different unit in the same army as the original game's protagonists.
* ''VideoGame/FalloutNewVegas'' is an odd case of a Gaiden Game that is more of a sequel to its predecessor (''VideoGame/{{Fallout 2}}'') than [[VideoGame/{{Fallout 3}} the actual sequel]] is: ''3'' was made by a different developer (Bethesda) than Black Isle, the developers of the first two, and moved the setting to the opposite end of the country. ''New Vegas'''s developer (Obsidian) had many key members in common with Black Isle, takes place closer to familiar ground, and incorporates many elements from the cancelled ''Van Buren'' project that was originally going to be ''Fallout 3''. Additionally, most of the add-ons for ''3'' and ''New Vegas'' have a separate map from the main game, as well as a self-contained story.
* The ''VideoGame/OgreBattle'' series has two. ''Ogre Battle: Legend Of The Zenobia Prince'', a [[NoExportForYou Japanese-only]] game for the UsefulNotes/NeoGeoPocket and ''VideoGame/TacticsOgreTheKnightOfLodis'', both of which tell the backstories of characters from ''VideoGame/OgreBattle'' and ''VideoGame/TacticsOgre'', respectively.
* The ''VideoGame/WorldOfMana'' series has a number of titles not in the main series -- ''VideoGame/LegendOfMana'', ''VideoGame/ChildrenOfMana'', and ''VideoGame/HeroesOfMana''. But what's more interesting is that the original game, released as ''VideoGame/FinalFantasyAdventure'' in the US....was actually called ''Seiken Densetsu: Final Fantasy Gaiden'' (and was in fact the first game released in the US to have a Chocobo in it!).
* ''VideoGame/DragonAgeOrigins'' has a couple {{DLC}} missions that don't star the Grey Warden: ''Leiliana's Song'', which explains how the secretive nun came to Ferelden, and ''Darkspawn Chronicles'', a WhatIf where the Warden didn't survive the joining and the Darkspawn won the war.
* ''VideoGame/BaldursGate'' had ''Tales of the Sword Coast'', an expansion for the first game that added three new optional dungeons that had nothing to do with the main story. The ''VideoGame/BaldursGateDarkAlliance'' games share the setting of the main games, but not the story.
* ''VideoGame/LufiaTheRuinsOfLore'' is one to the ''{{VideoGame/Lufia}}'' series, dealing with a subplot from ''VideoGame/LufiaIIRiseOfTheSinistrals'' rather than the overarching plot of the rest of the series. Even its Japanese name is ''Estpolis Gaiden''.
* ''VideoGame/{{Growlanser}}'' II it could be argued is more of a addendum to the first game than a full on sequel. For starters it has many elements that cause it to stick out in comparison to the rest of the series, such as having a voiced protagonist, a lack of a continuous over-world, no base building, plus a significantly shorter length (It can be beaten in around 15-20 hours in comparison to the 60-70 of the rest of the games in the series.) It also assumes knowledge the player is aware of the events of the first game (which is ironic because it [[NoExportForYou never left Japan.]])
* ''VideoGame/MarioAndLuigiPaperJam'', as a {{crossover}} with ''VideoGame/PaperMario'', is one to both series simultaneously, but moreso the former. As confirmed by WordOfGod, to keep the budget down, several musical themes are reused from earlier games and the settings and characters draw more from the main platformer games than other installments before. Adding to this, it's the only ''Mario & Luigi'' game to eschew NumberedSequels in its Japanese release.

* ''VideoGame/{{Gradius}} Gaiden'', the only ''Gradius'' title that allows the player to rearrange the power meter, and the second non-''VideoGame/{{Parodius}}'' game to have multiple selectable ships (the MSX title ''Nemesis 3'' being the first). And for that matter, the MSX version of ''Salamander'', and MSX exclusives ''Nemesis 2'' and ''3''. The MSX ''Salamander'' plays more like a ''Gradius'' title, and has several new features such as a powerup that temporarily stops the screen scrolling. ''Nemesis 2'' is an original title with the ability to fly into about-to-be-destroyed boss ships and obtain new powerups such as an upward-firing laser, at the cost of having a longer power meter. ''Nemesis 3'' is a retelling of the more mainstram ''Gradius II: Gofer no Yabou'' with ''Nemesis 2''-style gameplay. Also, the ''Salamander'' series is a gaiden series to ''Gradius''.
* ''VideoGame/RType Leo'' has gameplay significant from a "real" ''R-Type'' game. Instead of a Force Pod, you have two smaller pods that provide additional firepower and have a homing charge attack, and the plot takes place before any other games in the series. ''Armed Police Unit Gallop'' is also a Gaiden Game, featuring similar mechanics but involving police chases of criminals rather than extraterrestrial threats.
* ''VideoGame/{{Touhou}}'':
** The numbering of the four * .5 games (''Immaterial and Missing Power'', ''Shoot the Bullet'', ''Scarlet Weather Rhapsody'', ''Double Spoiler'', ''Hopeless Masquerade'' and ''Urban Legend in Limbo'') would imply that they're all gaiden games to the main series (Touhou 12.3, ''Hisoutensoku'', is an ExpansionPack to SWR), especially since none of them use the same gameplay system ([=IaMP=], SWR, HM and [=ULiL=] are 2D {{Fighting Game}}s, and [=StB=] and DS are {{Boss Rush}}es where you take pictures instead of fighting back). However, of the six, [=StB=] and DS are the only ones [[ExcusePlot without an actual plot]] -- whereas the events and new character introduced in [=IaMP=] are acknowledged in the [[AllThereInTheManual canon books]] ''Perfect Memento in Strict Sense'', ''Bohemian Archive in Japanese Red'', and ''Silent Sinner in Blue'' (SWR was made after those books came out).
** [=IaMP=] boss character Suika Ibuki appears in ''Subterranean Animism'', and the game actually elaborates on some of [=IaMP=]'s plot (that is, where the oni all went). Iku Nagae and Tenshi Hinanai from [=SWR=] are both in ''The Grimoire of Marisa''. The newest Gaiden Game, Touhou 12.8 ''Great Fairy Wars'', is a direct continuation to a chapter of a Touhou manga, ''Strange and Bright Nature Deity''. Basically, Touhou is undergoing ContinuityCreep.
* ''VideoGame/MetalSlug'' has a canon gaiden game on the UsefulNotes/GameBoyAdvance, detailing a new training facility that was overrun by Morden's forces. Best of all, two of the trainees, playable characters Walter and Tyra, single-handedly take it all back.
* ''VideoGame/TimeCrisis: Project Titan'', ''Crisis Zone'', and ''VideoGame/RazingStorm''. Project Titan was a PSX-only sequel starring Richard Miller. It most definitely took place after 1 (note Wild Dog's mechanical arm); how long is uncertain. It doesn't affect anything that happens afterward, so it's no surprise you don't hear about it. Crisis Zone and Razing Storm are unrelated games which use the TC2-and-later engine.
* ''VideoGame/{{Darius}}'' has its own gaiden game in the form of ''Syvalion''. You even have a Silver Hawk fly along side you in one stage and the metal dragon cameos in ''Darius Burst''.
* ''VideoGame/EpicBattleFantasy'' does this in a similar way to the Touhou examples above- and inverts it. How does it invert it? 1, 2, and 3 are basically RPG games. ''EBF 3.3: Bullet Heaven'' is a BulletHell game.
* ''Aleste Gaiden'', in contrast to other ''VideoGame/{{Aleste}}'' games, has the hero running and jumping in PoweredArmor and a relatively limited weapon selection. The ending reveals that it takes place in AnotherDimension from the original ''Aleste'', with the same protagonist and villain. Interestingly, ''Musha Aleste'' (''M.U.S.H.A.'') is officially a sequel to this game, whereas ''GG Aleste'' follows the alternate timeline of ''Aleste 2''.
* ''Franchise/{{Halo}}'':
** ''[[VideoGame/HaloSpartanAssault Spartan Assault]]'' is a side-story interquel which takes place between ''VideoGame/{{Halo 3}}'' and ''VideoGame/{{Halo 4}}''.
** ''[[VideoGame/HaloSpartanStrike Spartan Strike]]'' is a side-story which takes place both concurrently with the beginning of ''VideoGame/{{Halo 2}}'' and around the end of ''VideoGame/{{Halo 4}}''.
* ''VideoGame/StarFoxZero''[='=]s companion game, ''Star Fox Guard'', is a TowerDefense game starring Slippy Toad which is based around a twelve-camera security system. Creator/ShigeruMiyamoto himself visualises these games as TV shows, with ''Zero'' as a primetime series and ''Guard'' as a late night series.
* ''VideoGame/LinksCrossbowTraining'' for the Wii is vaguely set during the events of ''VideoGame/TheLegendOfZeldaTwilightPrincess'' and stars the same Link. The game's actual canon status is rather iffy, though.

* ''VideoGame/ColonyWars III: Red Sun'' feels like this in comparison to its two predecessors. The main character is a neutral bounty hunter with no ties to either of the main factions, it takes place concurently with ''Vengeance'' rather than after it and the League/Navy conflict is mostly in the background, with most of the missions instead involving feuds between newly-introduced factions and the protagonist investigating an outside threat.

* The Dead or Alive [=XTreme=] games are (even more) [[{{Fanservice}} fanservicey]] gaiden games of ''VideoGame/DeadOrAlive''.
* ''Jet Set Radio Future'' is this to ''VideoGame/JetSetRadio''. It doesn't continue off of or add to the continuity of the original game. If anything, it's set in an [[AlternateContinuity alternate timeline]].

[[folder:Tabletop Game]]
* ''TabletopGame/{{Warhammer}}'' and ''TabletopGame/Warhammer40000'' each have a number of spinoff tabletop games in their universes.
** Warhammer Fantasy's games include TabletopGame/WarhammerFantasyRoleplay, the gang-based ''TabletopGame/{{Mordheim}}'', American football parody ''TabletopGame/BloodBowl'' (even referring to the mystical god 'Nuffle'), the naval fleet based game ''TabletopGame/ManOWar'' and massive-battle ''TabletopGame/{{Warmaster}}''. 40k has the large-scale "narrative wargame" ''TabletopGame/{{Inquisitor}}'', space combat ''TabletopGame/BattlefleetGothic'', massive-battle ''TabletopGame/{{Epic}}'', all-Ork ''TabletopGame/{{Gorkamorka}}'', air-battle ''TabletopGame/AeronauticaImperialis'', gang-based ''TabletopGame/{{Necromunda}}'' and the role-playing game ''TabletopGame/DarkHeresy''.
** ''VideoGame/DawnOfWar'' was originally supposed to be this, creating an all-new SpaceMarine chapter, the Blood Ravens, to avoid stepping on continuity's toes. The fans liked them so much that Games Workshop [[AscendedFanon went ahead and canonized them, the games, and the events therein.]]
** There is also ''Path To Glory'' for fantasy which you play as an aspiring champion of chaos.
** Also there is ''Kill Team'' for 40k [[note]] ''not'' the videogame[[/note]] that has a small team of elite units infiltrating and completing a objective.
* ''TabletopGame/CallOfCthulhu'' is a tabletop game set in the eponymous universe created by ''Creator/HPLovecraft''. '''''Trail''' of Cthulhu'' is a lighter variant which masks the rate of player attrition by simplifying the rules. Similar in many ways, like the ''Dark Heresy'' example just above, but not quite the same.

[[folder:Third-Person Shooter]]
* The ''Franchise/MassEffect'' series has had multiple examples of this:
** ''Mass Effect: Galaxy'' (for the [=iPod=] Touch/[=iPhone=]) focuses on Jacob Taylor and Miranda Lawson between the events of the first and second game. Completing ''Galaxy'' unlocks more dialogue in ''VideoGame/MassEffect2''.
** The [=iOS=] game ''Mass Effect: Infiltrator'' runs concurrently with the events of ''VideoGame/MassEffect3'', and follows an ex-Cerberus operative who works to free a number of captive civilians from Cerberus' laboratories. The game has similar mechanics to the main game, and completing it allows the player to export a War Asset and a weapon over to ''3''.
** ''Mass Effect: Datapad'' is another [=iOS=] game integrated with the third installment, and includes a galactic Codex, the ability to receive personal messages from squadmates and various characters in the universe, and a strategy minigame that allows you to increase your Galactic Readiness in the main game.

[[folder:Turn Based Strategy]]
* Because EverythingsBetterWithPenguins, TurnBasedStrategy series ''Franchise/{{Disgaea}}'' has a platformer spin-off for the PSP called ''VideoGame/PrinnyCanIReallyBeTheHero'' starring everyone's favorite explosive waterfowl squad.
* ''VideoGame/DisgaeaInfinite'' (also for the PSP) can also be considered a Gaiden Game to the series. You also play as a Prinny in this game, however the approach is different than in the previous title.
* Website/FunOrb's "Armies of Gielinor" is a TurnBasedStrategy based on the history of the world of ''VideoGame/{{Runescape}}''.
* The aptly named ''VideoGame/FireEmblemGaiden'' is a side-story to the [[VideoGame/FireEmblemAkaneia original]] ''Franchise/FireEmblem'' game, and the UpdatedRerelease, ''Fire Emblem Echoes: Shadows of Valentia'' also links it to the distant past of ''VideoGame/FireEmblemAwakening'', while ''Fire Emblem: Thracia 776'' is one to ''[[VideoGame/FireEmblemJugdral Genealogy of the Holy War]]''. The two titles are generally considered full instalments in the ''Fire Emblem'' series, being the second and fifth respectively, though there are some portions of the Japanese fanbase who don't consider ''Gaiden'' to be a full ''FE'' game. Also present are the UsefulNotes/{{Satellaview}} instalments in the series, which are briefer games focusing on small groups of the cast of the first/third game doing things in the intervening time period between Dolhr's victory and the start of the first/third games; they were later remade and included as a bonus in ''New Mystery of the Emblem''.

[[folder:Visual Novel]]
* ''VisualNovel/PhoenixWrightAceAttorney'':
** The bonus case, only present on the DS version (the original Japan-only GBA version ends at the fourth case), features a case where only 5 characters (Phoenix, Edgeworth, Gumshoe, the Judge and the Bellboy) from the rest of the series appear, the rest being completely new. This is due to the case taking place between the first and second games, and the writers couldn't mess with the continuity already set by the sequels which had already been released in Japan. The plot and characters feel perfectly like a sidestory. The fifth case has been fully worked into the canon with ''VisualNovel/ApolloJusticeAceAttorney'' featuring Ema as the game's Gumshoe.
** ''VisualNovel/AceAttorneyInvestigationsMilesEdgeworth'', a Gaiden Game where you play as Miles Edgeworth, Nick's rival. It follows the same general formula except that Edgeworth is actully on the map as a sprite and walks around rather then looking at a static image. There is no court segments (Unless the case taking place in a court house counts), but witnesses are still cross examined in much the same manner as the main series. It now has its own sequel, becoming a Gaiden Series.
* ''VisualNovel/HigurashiWhenTheyCry'':
** ''Higurashi Daybreak'', a doujin game that's literally [[WordOfDante become a canon side story]].
** There's also Jan, in which the characters can (depending on the mode) go crazy and kill each other just like usual, and they're dueling with... [[CookingDuel mah-jong?]]
** ''VisualNovel/UminekoWhenTheyCry'' will soon have its own Gaiden Game in the form of ''Umineko No Naku Koro Ni - Tsubasa'', and will contain all the side stories released beforehand.
* ''VideoGame/AbsoluteDespairGirls'' is this to the ''Franchise/DanganRonpa'' series, being a story-heavy ThirdPersonShooter rather than a VisualNovel set between the [[VisualNovel/DanganRonpa first]] and [[VisualNovel/SuperDanganRonpa2 second]] games and not having a mutual killing game, starring the first game's protagonist's sister and and secondary character from the first game.
%%* ''VisualNovel/{{Clannad}}'': ''[[AlternateUniverse Tomoyo After: It's a Wonderful Life]]''.
%%* ''Kud Wafter'' is this to ''VisualNovel/LittleBusters''.