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[[caption-width-right:256:The ninja way knows neither good nor evil.]]

''Ninja Gaiden'' is an action game series produced by Creator/{{Tecmo}} (now known as Creator/{{Koei}} Tecmo) centering around Ryu Hayabusa, a {{ninja}} from the Dragon Clan, who gets involved with government conspiracies, kicks loads of ass and slaughters legions of supernatural beings along the way.

The series dates back to 1988 with two simultaneously developed games under the same title: an arcade version that was a side-scrolling [[BeatEmUp beat-'em-up]] in the vein of ''VideoGame/DoubleDragon'', and a more popular console version for the Usefulnotes/NintendoEntertainmentSystem, a [=2D=] action platformer notable for being one of the earliest action games to feature cinematic sequences between stages. The NES version would spawn two sequels, a UsefulNotes/GameBoy prequel, a couple of stand-alone versions for other platforms and an [[AnimeOfTheGame OVA]] set after the events of the NES trilogy before Tecmo discontinued the series after the release of the ''Ninja Gaiden Trilogy'' [[CompilationRerelease compilation]] for the {{UsefulNotes/Super N|intendoEntertainmentSystem}}ES in 1995.

However, Ryu's presence in Tecmo's ''Videogame/DeadOrAlive'' fighting game series helped keep the series alive within the public's consciousness, leading to a revival in 2004 for the UsefulNotes/{{Xbox}} by ''DOA'' developer Team Ninja simply titled ''[[RecycledTitle Ninja Gaiden]]''. Since then, ''Ninja Gaiden'' has become Team Ninja's other flagship franchise, leading to even further sequels and spinoffs.

There was also a set of licensed versions produced by Sega for their consoles in 1992. Rather than being ports of the previous Tecmo versions, Sega produced three different games that were unique to each platform. The UsefulNotes/GameGear version had the widest release of these versions, being available in North America, Europe and Japan (where it was released under the ''Ninja Gaiden'' banner instead of the usual ''Ninja Ryukenden''), while the UsefulNotes/SegaMasterSystem version was available exclusively in Europe. The UsefulNotes/MegaDrive version, which was a beat-'em-up similar to the arcade game, was never released, but was leaked in the form of a pirated version that was still [[ObviousBeta in an unfinished state]].

!!'''The NES Trilogy (1988-1991)'''

In the first game, Ryu receives a letter from his father Joe Hayabusa (renamed Ken Hayabusa in the original localization), saying that should he not return, Ryu is to journey to America and contact a man named Walter Smith. Believing his father dead, Ryu goes to America to carry out this request. After battling a large man with an axe in a bar, he is subdued by a woman with a tranquilizer gun. He awakens in a prison cell, where the woman (Irene Lew) frees him and gives him a mysterious, grotesque statue. Ryu is puzzled by this, but presses onward. He meets with Smith, who identifies the statue as one of the Demon Statues, a pair of [[ArtifactOfDoom Artifacts of Doom]] he and Joe discovered and vowed to protect. As Ryu and Smith talk, the statue is stolen by another ninja. Ryu gives chase, and recaptures the statue, but returns to find Smith dying. Ryu vows to carry on his work, protecting the Demon Statues.

However, Ryu is captured by the CIA and brought before A. Foster, the head of the agency. Foster reveals that Irene is one of their agents, and that she is tracking down a man known as Jaquio, who seeks to release [[SealedEvilInACan the powerful demon sealed in the statues]]. Foster orders Ryu to take out Jaquio; Ryu, remembering his oath to Smith, complies. Air-dropped into the jungles of Brazil, he makes his way to Jaquio's fortress, where he finds Jaquio has Irene at gunpoint. Jaquio reveals he has the second Demon Statue already, and [[HostageForMacGuffin demands Ryu's statue in exchange for Irene's life]]; Ryu, being new at the whole hero thing, complies. Jaquio's an old hand at villainy, however, and simply absconds with the statues and the girl -- but not before sending Ryu hurtling down a {{trapdoor}} to the catacombs below.

Undaunted, Ryu fights his way to the top of the fortress, where he again encounters Jaquio and Irene... as well as Ryu's father, who, [[NotQuiteDead while not dead]], is under Jaquio's mind control. Ryu gets the better of Jaquio in battle, and in desperation, Jaquio launches a magic bolt at Ryu, but his father comes to his senses, [[TakingTheBullet intercepts the bolt]], and dies. The enraged Ryu proceeds to kill Jaquio... but he's too late, for [[OhCrap Jaquio has released the demon from the statues]]!

Ryu bravely fights the demon, sealing it once more. After the battle, Foster radios Irene and orders her to assassinate Ryu and take the statues. Irene hesitates, and Ryu takes her radio and tells Foster the next time they meet, it will be as enemies.

Quite a bit more elaborate than the SaveThePrincess plots of the day, isn't it?

''Ninja Gaiden II: The Dark Sword of Chaos'' and ''Ninja Gaiden III: The Ancient Ship of Doom'' both had similarly complex plots, centered around their titular {{MacGuffin}}s. Due to space considerations, we won't get much more into detail here; however, they offer just as many, if not more, twists and turns as the first game.

As for the actual game that takes place between the {{cutscene}}s? ''Ninja Gaiden'' played a lot like ''VideoGame/CastlevaniaI'' -- only faster paced and with a more acrobatic protagonist. The games were the very epitome of NintendoHard, with enemies coming at you from every direction at once. Gamers didn't seem to mind, however -- even those who found the challenge to be too much suffered through it anyway to see the next chapter in Ryu's saga.

!!'''The Team Ninja series (2004-current)'''

Sometime in 1999, Itagaki and Team Ninja began work on their first "action" title, aside from their on-going ''Dead or Alive'' series. Although then-Tecmo wanted a tie-in for this new revival with the NES trilogy, this Xbox version of ''Ninja Gaiden'', released in 2004, involves none of the elements. In an interview, Itagaki mentioned he "prefer not to be influenced by or base it on the original story". While Ryu's still the protagonist, none of the above elements are ''explicitly'' mentioned.

The story establishes Ryu's a member of the Dragon Ninja Clan, charged with protecting the Dark Dragon Blade, a {{BFS}} imbued with some pretty extraordinary powers. After the game's tutorial level, he's informed that the Hayabusa Village has been destroyed. When Ryu investigates, a samurai pledged to the Holy Vigoor Emperor, Doku, kills him with the Dark Dragon Blade.

Don't worry, [[BackFromTheDead he gets better]].

Thus, the game embarks Ryu upon a [[RoaringRampageOfRevenge ferocious quest for revenge]] and the retrieval of the Dark Dragon Blade. The details of the plot are convoluted and don't add up to anything particularly extraordinary, but Ryu slices and dices his way through Vigoorian soldiers, tanks, zombies, ninjas and ghost piranhas.

The Xbox version is, as the kids these days say, [[NintendoHard difficult]]… really, ''really'' difficult… as in "throw-your-controller-at-the-screen-and-scare-the-dog '''difficult'''". In contrast to other {{Hack And Slash}}ers, enemies avert MookChivalry and have no compunctions about suffocating the player at every available moment. In fact, beating this game is an achievement. Hell, there was an UpdatedRerelease called ''Ninja Gaiden Black'' which not only fixed gameplay imbalances, placed more enemies and bosses and added in "Combat Missions", it included two new modes: a "[[MercyMode super-duper-mega-easy]]" mode and an "[[UpToEleven even harder]] than HarderThanHard mode"! Unfortunately, it didn't help the "super-duper-mega-easy" mode was quite hard itself, difficult to the point of inducing trauma.

The game was critically acclaimed by all, and considered the best 3D HackAndSlash game of its time. A title that it still keeps in the eyes of a lot of people, specially the ''Black'' version. Many praised its preserved difficulty from the NES trilogy, but without being unfair, alongside gorgeous visuals and attention to detail in combat and environments by pushing the Xbox beyond its hardware limitations. An EnhancedRemake of ''Ninja Gaiden Black'' called ''Ninja Gaiden Sigma'' for the Sony UsefulNotes/PlayStation3 was released in 2007, rounding out the last gameplay additions with a new character ([[ActionGirl Rachel]]), new weapons and enemies, while making it look more pretty with the console's high-defintion capabilities. It also removes or simplifies some puzzles that contained too much back-and-forth.

In 2008, ''Ninja Gaiden: Dragon Sword'' was released for the UsefulNotes/NintendoDS. This GaidenGame sequel set six months after ''Ninja Gaiden'' tells of Ryu and his journey to save his apprentice, Momiji, and find the Dark Dragonstones that can resurrect an ancient Dark Dragon. In the same year, the true sequel ''Ninja Gaiden II'' was released for the Microsoft UsefulNotes/Xbox360, where another ArtifactOfDoom the Dragon Lineage were guarding, the Statue of the Archfiend, is stolen. Ryu must travel the world chasing the Four Greater Fiends as they attempt to resurrect the [[SealedEvilInACan Archfiend itself]]. Both games retain the difficulty of ''Ninja Gaiden'' (''Ninja Gaiden II'' arguably even harder) and the stories are serviceable, yet the latter's almost completely nonsensical, with EverythingTryingToKillYou more aptly applied. For example, at one point a giant armadillo with marginal fire ElementalPowers appears with [[GiantSpaceFleaFromNowhere no apparent connection to the villains]].

Following the release of ''Ninja Gaiden II'', Itagaki stepped down from Team Ninja and left the now merged Tecmo Koei. Current series director and producer Yosuke Hayashi took over and released an UpdatedRerelease of ''Ninja Gaiden II'' on the [=PS3=] as ''Ninja Gaiden Sigma 2''. Notably, the game partly resolves the nonsensical nature of the plot in the 360 original, but also throws in new characters ([[CanonImmigrant Ayane]] from the ''Videogame/DeadOrAlive'' series and [[TookALevelInBadass Momiji]], plus the return of Rachel) and scenarios, a co-op mission mode, a "Chapter Challenge" mode and a prologue that links ''Dragon Sword'' to current continuity (''Ninja Gaiden II'' never makes a mention of ''Dragon Sword''). It also significantly tones down the 360 game's gore and the number of enemies, making them more resilient instead.

In February 2012, ''Ninja Gaiden Sigma Plus'', an enhanced version of ''Sigma'' was released for the Vita, it featured new sets of accesories for both Ryu and Rachel, as well as utilizing the Vita's touch and motion controls.

''Ninja Gaiden III'' was released in March 2012 on both [=PS3=] and 360. Contrary to his predecessor, Hayashi wanted to make the game "more accessible", and the game, while not exactly easy, is noticeably more forgiving than the first two games. For the first time in the series, ''Ninja Gaiden III'' features CompetitiveMultiplayer. Set after ''Ninja Gaiden II'', Ryu receives a request from the Japanese government, after terrorists take the British Prime Minister hostage, demanding his appearance. He travels to London and faces the mysterious foes, led by the enigmatic "Regent of the Mask", who places a curse on Ryu's right arm, making him feel the pain and hatred of the people he killed. The story also marks the return of scriptwriter [[VideoGame/ChronoTrigger Masato]] [[VideoGame/FinalFantasyVII Kato]] to the series, bringing back the deep narrative seen in the NES trilogy. It effectively ties the modern games into overall continuity. ''III'' also has a much more cinematic and dramatic feel compared to its predecessors.

Alas, while ''Ninja Gaiden III'' was successful commercially, it wasn't as much critically with players criticizing the aforementioned dumbed-down difficulty, excessively streamlined gameplay and a lack of replay value. Many fans of the earlier two titles particularly panned it: its attempt at story unwelcomed, its "cinematic and dramatic feel" was panned as needlessly boring ''and'' nonsensical (watch super-ninja Ryu Hayabusa [[GoodIsBoring ride around the desert in a jeep!]]) whereas ''II'' at least was entertaining and nonsensical and those who'd enjoyed the fast-paced, unforgiving but fair combat of the previous titles particularly blasted the decision to remove all other weapons and inject [[ProtagonistCenteredMorality poorly-done moral choices]] in their place.

The game had a re-release in late 2012 on the UsefulNotes/WiiU (January 2013 in Europe) entitled ''Razor's Edge'', with Team Ninja addressing the flaws, such as re-adding back dismemberments, brutal difficulty, fleshed out gameplay, weapon acquisitions and upgrades and additional playable characters (Momiji, Ayane and the first appearance of [[CanonImmigrant Kasumi]] from ''Videogame/DeadOrAlive''). Also, some of the most disliked cutscences were eliminated. Ports for the [=PS3=] and [=Xbox 360=] were released in April 2013. Both versions include all the downloadable content from the Wii U version already on the disc.

Also in 2013, ''Sigma Plus 2'' was released on the Vita, it was widely considered superior to Sigma 2, as it restored all the gore that was cut on the [=PS3=] version.

In 2014, a collaboration with Spark Unlimited and Comcept gave birth to a SpinOff called ''VideoGame/YaibaNinjaGaidenZ''. The protagonist is Yaiba, one of the many victims of Ryu Hayabusa, who is BackFromTheDead to chase the man who killed him. The tone, graphical style and gameplay differ vastly from the main series, though. [[EverythingsDeaderWithZombies Also, there are zombies]].

'''Now with a good [[Characters/NinjaGaiden Character Sheet]], thus character tropes go there.'''

!!The ''Ninja Gaiden'' video game series provides examples of:


[[folder:General tropes]]
* ActionGirl: Although this series falls for the FauxActionGirl a little bit too often, Ayane, Momiji and Rachel in ''Sigma 2'' definitely play the role straight.
** Irene should count: those times when she isn't ''already'' captured [[spoiler: or dead]] she can definitely hold her own. She even pulls her own BigDamnHeroes [[spoiler: in ''The Ancient Ship of Doom'' when she rescues Ryu from death with the help of a submachinegun]].
* AnachronicOrder: Some ContinuitySnarl and FlipFlopOfGod aside, the series goes like this, from a young 18 years old Ryu to a 23 years[[note]]25 as of ''[=DOA5=]''[[/note]] old Master Ninja:
** ''Ninja Gaiden Shadow'' (Game Boy) --> ''Ninja Gaiden'' (Xbox) --> ''Dragon Sword'' --> ''Ninja Gaiden II'' --> ''Ninja Gaiden 3'' --> ''Ninja Gaiden'' (NES) --> ''The Ancient Ship of Doom'' --> ''The Dark Sword of Chaos'' --> ''Ninja Ryukenden'' OVA --> ''Dead or Alive'' series
* TheAnimeOfTheGame: The 1991 OVA, which is set after the events of the second NES game.
* AppropriatedTitle: The original incarnation of the franchise was known as ''Ninja Ryukenden'' (Ninja Dragon Sword Story) in Japan and ''Shadow Warriors'' in Europe. When Team Ninja rebooted the series, they chose to stick with one title worldwide instead of having a different {{market based title}} for each region. This caused a side effect which led to the Japanese versions of the game being easier to distinguish (the older series is known as ''Ninja Ryūkenden'', while the rebooted version is ''Ninja Gaiden''), a privilege not afforded to American fans.
* ArtifactOfDoom: The Dragon Ninja clan apparently exists to look after these, keeping the lids on various [[SealedEvilInACan cans of evil]].
** They aren't too good at it though, considering how [[RedshirtArmy everybody but Ryu gets killed. Twice]].
* ArtisticLicenseGeography: The arcade game ending involves Ryu in a small boat heading back to Japan. Both Tokyo Tower and Mt. Fuji are together in the same skyline in the shot.
* BattleCouple: Ryu the badass OneManArmy {{Ninja}} and Irene/[[spoiler:Sonia]] [[TheGunslinger the Girl With Guns]] then later ''MissionControl''; still together in the ''Dead or Alive'' series.
* CanonImmigrant: The fact Ryu married Irene and opened up a Curio/Antique Shop to run it together in the OVA carries over to the ''Dead or Alive'' series, which is set after everything that happened in his solo series. After Igakaki's re-imagination for the ''Ninja Gaiden'' series on the Xbox, it looked like this fact got {{retcon}}ned for good, but it took his departure from Team Ninja and Hayashi's intervetion as the new director to put the pieces back together in ''Dead or Alive: Dimensions''.
** Looking the other way around, Ayane would be the biggest immigrant in the series, followed by her half-sister Kasumi.
* ContinuityCameo: Ayane from ''Dead or Alive'' shows up in the modern trilogy. Inverted with Irene, who makes a cameo in ''Dead or Alive: Dimensions'' as Ryu's CIA contact during the story mode. [[spoiler: The cameo doubles as confirming Sonia from ''Ninja Gaiden II'' as Irene's alias]].
** [[spoiler:[[VideoGame/DeadOrAlive Kasumi]]]] gets a [[TheFaceless faceless]] cameo in ''Sigma 2''. [[spoiler:[[VideoGame/DeadOrAlive Hayate]]]] is name-dropped in ''III'' and certain characters in ''Dragon Sword'' appear on-screen in the same game.
* ContinuityNod: With ''Dead or Alive: Dimensions'', Hayashi has tried fixing some of Itagaki's mess, with Irene making a cameo in particular, as an attempt at settling Ryu's appearance in ''Dead or Alive'' as being placed years after his solo adventures.
** Within the franchise, ''Sigma 2'' gives many throwbacks to previous games, such as the inclusions of Rachel from ''Ninja Gaiden'' and Momiji from ''Dragon Sword'', something ehe original release ''Ninja Gaiden II'' for the 360 didn't trouble itself with. Similarly, a number of enemies in ''II'' were taken directly from ''Dragon Sword'' (the Rasetsu ninjas and the red dragons, among others).
** In the New York level of ''Ninja Gaiden II'', you can see some scrolling signs reading "[[Videogame/DeadOrAlive Doatec]]".
* ContinuitySnarl: Ryu's appearance in ''Dead or Alive'', since the first installment made clear in his character bio that the current Ryu is, {{canon}}ically, the one who already has ventured through all his solo games, reinforced by stating he's a Curio Shop owner, something that would only happen after the end of the NES trilogy with Ryu married to Irene and everything else, namely from the OVA. Itagaki then envisioned the ''new'' ''Ninja Gaiden'' series for the Xbox and kind of made continuity unstable, such as having Ryu wear his "Black Falcon" outfit as the default outfit from ''Dead or Alive 4'' and onward, while making no mention of Irene or his shop ''in-game''.
** As of ''Dead or Alive: Dimensions'', things seemed to have been fixed, thanks to a couple of cameos here and there.
* ConvectionSchmonvection: In ''Ninja Gaiden II'', Ryu can run on lava and swim in it, although it starts to hurt later. Possibly justified since he can set himself on fire every time he uses fire-based Ninpo (and other elemental Ninpo).
** Back in ''The Dark Sword of Chaos'' and ''The Ancient Ship of Doom'', Ryu can easily cross a firepit or the caldera of an active volcano and won't suffer injuries unless he falls into the flames or lava.
* DidYouJustPunchOutCthulhu: Both incarnations of the franchise involve Ryu eventually fighting giant demons.
* DressedLikeADominatrix:
** One of the Ancient Greater Fiends, Ishtaros, is a powerful evil goddess. She wears black thigh-high high-heeled boots, some weird leather straps on her arms, and that's pretty much it. One of her arms sports FemmeFatalons, the other one is a tentacle she uses like a whip.
** Rachel too uses this aesthetic. Her combat suit is made of black leather, and consists of thigh-high boots, gloves of varying length, and a leotard which exposes her cleavage and lower midriff.
* DualBoss: The NES series has some of this but the modern series is fond of pitting you against two to three bosses at once, sometimes with mooks involve! ''Razor's Edge'' takes it UpToEleven.
** Curse you, Giants of the Underworld!
** Also, the "Dragons" pro wrestling duo in the arcade version.
** The Tengu brothers in ''Sigma 2'', although it's an odd example since you alternatively fight them alone and together several times throughout the game (see RecurringBoss below).
** The Quetzalcoatl in ''Ninja Gaiden II''
** In the original trilogy, it's the Kelbeross in the first two games, followed by Great Koganei in the third.
* EldritchLocation: The Realm of Chaos, the Labyrinth of Shadows, and the eponymous Ancient Ship of Doom
* EmpathicWeapon: The Dragon Sword
* FanServicePack: ''Dead or Alive: Dimensions''[='=] inclusion of [[spoiler:Irene's cameo]] and revealing that [[spoiler:Sonia was her alias in ''Ninja Gaiden II'' for the Xbox 360]], pretty much "upgraded" all of [[spoiler:Irene's previously known portrayal in the classic trilogy]].
* GratuitousJapanese: The original Japanese version was titled ''Ninja Ryukenden'' (''Ninja Dragon Sword Story''), so the localization's title almost makes it seem like a GaidenGame when it isn't at all.
* GravityIsPurple: The Art of The Piercing Void, one of Ryu's most powerful ninja techniques, allows him to control gravity in order to create a black hole surrounded by purple energy.
* HappilyMarried: Ryu and Irene after the NES trilogy, during the OVA and carried over to ''Dead or Alive'', until this fact was stopped being mentioned in the latter after Itagaki envisioned the modern trilogy, possibly in an attempt to discard the idea of his creation being a long {{prequel}} for the original NES trilogy, turning into a [[AlternateContinuity new continuity]] altogether, and leaving Ryu free for new [[LoveInterest interests]]. It took ''Dead or Alive: Dimensions'' to fix the timeline again, namely bringing Irene back to make things stable... although the game is still very vague on the romance/marriage matter.
* HighlyVisibleNinja: Who said ninja games need a stealth mechanic? Considering Ryu has the access of the Dragon Sword and he's constantly facing demons and fiends that might not be fooled by stealth easily, perhaps stealth wasn't that necessary.
** ''Ninja Gaiden II'' ''seemed'' like you could be stealthy for once, until it gets retracted in a few seconds. How fast can you replace a searchlight that seemingly '''exploded''' for no reason?
** ''Ninja Gaiden III'' introduces stealth kills, although they are totally optional.
* KeepItForeign: The series' international title of ''Ninja Gaiden'' was chosen because Tecmo thought ''Ninja Ryukenden'' was hard to pronounce for Westerners. Interestingly, evidence seems to suggest that ''Ninja Gaiden'' was actually the original title (since the original arcade game was developed as a parody of American ninja films and their misunderstanding of Japanese culture), with ''Ninja Ryukenden'' being something Tecmo came up later due to the original title being too nonsensical for Japanese players.
* LargeAndInCharge: In both the NES trilogy and modern games, the bosses literally loom over Ryu Hayabusa. But just like [[FistOfTheNorthStar Kenshiro]], [[{{VideoGame/Doom}} the Doomguy]], [[{{VideoGame/Metroid}} Samus Aran]] and [[{{Franchise/Castlevania}} the Belmont Clan]], size means jack shit to our resident superninja, as he can and will carve a path through his enemies.
* MultipleChoicePast: It all comes down to Tecmo Koei simply establishing an official timeline without producers stating their own versions. Until then, it's not entirely clear which game represents Ryu's [[OriginsIssue first true adventure]]: the arcade game, the NES trilogy or the modern series.
* NintendoHard: If there's anything that can be said to be consistent about the series, it's that all of the entries are thumb-breakingly difficult. For the newer series, the guys at Team Ninja know it. You get an achievement for continuing enough times!
* NoPronunciationGuide
** A lot of people tend to mispronounce the title as "Ninja Gay Den" (rather than "Ninja Guy Den").
** And despite the fact that the characters call Ryu's name as "Ree-yu", some reviewers and critics ''still'' mispronounce it as "Ra-yu". Just like that other [[StreetFighter Ryu]], or any other [[AProtagonistIsRyu Ryu]] for that matter.
* RatedMForManly: Especially the modern series.
* {{Retcon}}: Some worth of mention, as Tecmo passed the series around to just about any willing developer and producer: Natsume, Team Ninja, Itagaki, Hayashi, etc. Of course, each had their own visions for the series:
** ''Ninja Gaiden Shadow'' is said to be set three years before the NES trilogy. Add to the fact Ryu is in his early 20s in the NES games don't match up with the modern trilogy, either.[[labelnote:Explanation]]This is the major reason why FlipFlopOfGod is heavy in regards to the post-2004 games being a {{Prequel}} to the NES trilogy: Ryu from 20 to 23[[note]]25 as of ''[=DOA5=]''[[/note]] years-old ventured through the trilogy and settled in the ''Dead or Alive'' series just as Ryu from 21 to 22 years-old gone through the present series and settled in ''Dead or Alive'' series at 23[[note]]25 as of ''[=DOA5=]''[[/note]]. The only way to reconcile this is by saying Ryu has done ''both'' sagas at around the same time.[[/labelnote]]
** Irene became a walking {{Retcon}} herself [[spoiler:when "Sonia" was confirmed to be another one of her codenames she uses on the field ''Dead or Alive''. Now it seems Ryu actually knew Irene before the NES series in the 360 version of ''Ninja Gaiden II'', while in the first NES game he certainly doesn't find "Sea Swallow" familiar to a certain Sonia he met earlier. Irene's appearance [[SarcasmMode of course was always]] that of a blond buxomed babe with pale skin instead of a brunette with modest body proportions; maybe she was [[WildMassGuessing wearing a disguise]] in the NES series]]?
** Ryu and Irene's marital status. The first ''Dead or Alive'' states they're HappilyMarried and Irene dutifully runs their Antique Shop while Ryu is away fighting in the tournament. In the next ''Dead or Alive'' tournament, their marriage became a mysterious subject: Ryu still is an Antique Shop owner, but Irene isn't mentioned in his bio anymore; in fact, it was doubtful that Irene ever existed from the second tournament onwards. When ''Dead or Alive: Dimensions'' was released, it recaps the first four tournaments and brought her back into the fray, but the marriage remains a mystery and suddenly Irene's a CIA agent again. The recap of ''Dimensions'' just goes as far as to imply they're romantically involved.
** Joe/Ken Hayabusa's whereabouts. Ryu's father dies in the NES trilogy, yet he's alive and kicking in the modern series, which is totally fine since it's a {{prequel}}. In enters ''Dead or Alive'' and make things difficult, as the first game makes no mention of Joe at all; it doesn't even touch upon the Hayabusa Clan, either. It only shows that Ryu is taking the position of clan leader for the moment and doesn't say anything else since his father was always fond of leaving his son to taking care of the clan while he spent seasons training on top of the mountains.
* SequentialBoss: The NES trilogy, plus the Vigoorian Emperor in the Xbox ''Ninja Gaiden''. Most bosses in ''III'' are also like this (which may explain why they have no life-bar).
* SingleStrokeBattle: The attract cinematic of the arcade version features a battle between the player character and a hockey mask-wearing {{mook}}. Never bring brass knuckles to a sword fight...
* SleevesAreForWimps: Ryu's arms are the only skin he bares in both incarnations.
* TenMinuteRetirement: While some elements of the OVA became CanonImmigrant for the ''Dead or Alive'' series (and by proxy the modern trilogy), the fact Irene retired from being a CIA agent to run an Antique Shop with Ryu didn't stick, at least in the {{Retool}} ''Dead or Alive: Dimensions'', where Irene acts as MissionControl for Ryu during his mission. It's unclear if she still is involved with their Antique Shop.
* UpdatedRerelease: Every modern game had at least one.
** For the Xbox ''Ninja Gaiden'', there's ''Black'', ''Sigma'' ([=PS3=]) and ''Sigma Plus'' (UsefulNotes/PlayStationVita).
** For ''Ninja Gaiden II'' (UsefulNotes/Xbox360) there is ''Sigma 2'' ([=PS3=]) and ''Sigma 2 Plus'' (Vita)
*** ''Sigma 2'''s case is a bit special though. Due to an exclusivity contract with Microsoft, ''II'' could not be ported onto the [=PS3=]. The only way to do it after Itagaki left was to add, remove and change so many things that ''Sigma 2'' would be considered an independent game rather than a mere port. It worked: although the levels, combat system and enemies are pretty much the same, the playing experience is quite different.
** For ''Ninja Gaiden 3'' ([=PS3=][=/=]360) there is ''Razor's Edge'' (UsefulNotes/WiiU, and then to [=PS3=][=/=]360).
** ''Ninja Gaiden Trilogy'' for the SNES can technically be counted as one for the NES series, though it winds up as a subversion. It uses the same 8-bit graphics, but in a couple levels in ''The Ancient Ship of Doom'' that had amazing 8-bit multiple parallax scrolling backgrounds, became single static scrolling backwards. It was actually a downgrade.
* TheVerse: ''Ninja Gaiden'' and ''Dead or Alive'' are one in the same universe, with the modern trilogy marking the earliest events, followed by the NES trilogy, and capping off with the ''Dead or Alive'' tournaments as the lastest.
* WallJump

[[folder:Tropes in the NES trilogy]]
* AlienSky: As Ryu approaches the gate to the Realm of Chaos in ''The Dark Sword of Chaos'', he's greeted by an eerie violet sky with strange stars hanging too close to the surface.
* AllThereInTheManual:
** Ryu doesn't learn Irene's real name until the very end of the first game. However, the manual already spoils this fact. However, the original Japanese manual made her name a complete mystery.
** The names of the four human bosses Ryu must face and then some are described in the manual. for the firs tgame
** The same thing also applies for said first game to the name of each of the stages.
* AirJousting: Both Ryu and his old man suck at it in the Original Trilogy.
** And after twenty-plus years, Ryu '''still''' sucks at it, as he attempts this in [[{{WebAnimation/DeathBattle}} his death match]] against [[{{VideoGame/Strider}} Strider Hiryu]] and fails epically.
** He ''does'' manage to eke out a draw (i.e., killed the mook) in the Arcade intro of Ninja Gaiden.
* AscendedGlitch: While Ryu could always stick to walls, he could only WallCrawl on select surfaces with ladder-like patterns on them in the original. However, with a little practice, it was easy to jump away from the wall and curl back onto it at a higher spot (which made several areas with difficult platforms, particularly Stage 5-3, much easier). Starting with ''The Dark Sword Of Chaos'', he was able to crawl up any wall.
* AttackDrone: The Shadow Clones from ''The Dark Sword of Chaos'', which follow in Ryu's footsteps ''precisely'' and attack when he does, at no cost. He can have up to two clones out at a time.
* AwesomeButImpractical: The spinning slash and fire shield in the first game. The first causes you to do a spinning slash every time you attack while jumping, which can deal obnoxious damage to bosses, even killing the first one in one hit if landed correctly. The problem is it causes you to do a spinning slash every time you attack while jumping, meaning you can't control how you use your special attack energy, and will probably run out of it (unless you know the trick: hold down while attacking). The fire shield makes you invincible for a little while, but the problem is that when it times out, you lose it and get nothing to replace it.
* AwesomeMcCoolname: The name of the stages in the original trilogy were pretty cool. One such name is "Place of Red Execution", where Ryu fights Bloody Malth in the first NES game.
* BackFromTheDead / DisneyDeath: Irene after being sacrificed for Jacquio's goal in ''The Dark Sword of Chaos''. She gets resurrected by the Dragon Sword's magic in the ending.
* BaitAndSwitchGunshot: After beating first boss in ''The Dark Sword of Chaos'', Dando the Cursed, Ryu meets a mysterious army operative who pulls a gun on him. Before Ryu can react, the man shoots...to finish off the monstrous Dando, who Ryu hadn't quite finished off.
* BeatThemAtTheirOwnGame: A villainous version. Most of the bosses in ''The Ancient Ship of Doom'' use Ryu's Ninja Arts such as the Windmill Throwing Star or mass-fire versions of the Art of the Fire Wheel.
* {{BFS}}: The titular Dark Sword of Chaos is just gigantic, yet Ashtar can wield it easily with one hand.
* BigBad
** Jaquio in the first NES game.
** Ashtar in ''The Dark Sword of Chaos'' and [[TheChessmaster the orchestrator]] of the events of the first. [[TheManBehindTheMan His position gets hijacked]] when [[spoiler:the Demon is revived (twice!) inside Jaquio's body by the Dark Sword of Chaos]].
** [[spoiler:Clancy]] in ''The Ancient Ship of Doom'', after doublecrossing [[TheDragon his]] [[UnwittingPawn boss]].
* BlindIdiotTranslation: ''Basaquer'', ''Kelbeross'', ''Malth'' and even BigBad ''Jaquio'' fall pray to this in the original NES trilogy. Their actual names were supposed to be "Berserker," "Cerberus", "Mars" and "Devil King" (Jakiō.) The mistranslated names do have plenty of charm, though...
** "Dando the Cursed" in ''The Dark Sword of Chaos'' is supposed to "The Damned One". This one is more forgivable, being an actual swear.
* BloodyBowelsOfHell: In ''The Dark Sword of Chaos'', the last stages take place in the Realm of Chaos. They steadily become more organic, with pulsing organs and faces on the walls, dripping ooze, and veins running across every surface.
* BossBonanza: One major source of the trilogy's notoriously brutal difficulty. At the end of the first game, you had to fight three bosses in a row, and your health would not be replenished after victory in the first two. Death at the end hands of any boss would result in being sent back to the start of the last level. This made learning boss mechanics through trial and error extremely difficult due to the long amount of time it took to get back to them after a defeat.
* CaptainErsatz: The mook with a hockey mask and [[MacheteMayhem a machete]] (named Jackson) is based on [[Franchise/FridayThe13th Jason Voorhees]].
* ChainReactionDestruction: Either that or bosses in the NES games carry a set of firecrackers which activate upon death.
* CheckPointStarvation: The first NES game was generally pretty good with checkpoints, as you would usually respawn at the same screen you died at...unless you died to a boss, in which case you're taken back to the beginning of the stage. if you're unfortunate enough to die at any of the three final bosses, however, you're taken ''[[UpToEleven all the way back to the start of 6-1!]]''
* ComicBookAdaptation: The ''Magazine/NintendoPower'' Strategy Guide for ''The Dark Sword of Chaos'' followed the game's story between gameplay tips and tricks as a fully drawn comic book. [[http://www.hardcoregaming101.net/ninjagaiden/nintendopower-1.jpg Ryu's encounter with Ashtar]] is a stand-out moment.
* CueTheSun: The {{happy ending}} of the first and third NES games.
* CutSong: "Inevitable" in ''The Dark Sword of Chaos'', which can only be heard with an NSF player.
* {{Cutscene}}: One of the first games, if not, [[TropeMaker the first game to incorporate these]] in between levels to tell a cohesive story.[[note]]Technically, the first VideoGame/CaptainTsubasa game came first, but that game wasn't released in North America until 1992, where it was [[DolledUpInstallment dolled up]] as "Tecmo Cup Soccer" (referred to on the title screen as "Tecmo Cup Soccer Game").[[/note]]
* CutsceneIncompetence: The first game contains one of the earliest examples ever of this trope. Despite being an elite ninja, Ryu is knocked out and captured by Irene Lew in a cutscene after the first level, and only gets out of prison after she lets him out. He later gets captured by CIA agents (the second time he's captured in a span of 3 levels) and forced to work for them. Eventually he is manipulated by a HostageForMacGuffin situation in which he hands over the demon statues Jaquio to prevent him from killing Irene. Natrually, Jaquio takes the statues, doesn't release Irene, and dumps Ryu down a pit trap, forcing him to fight through long levels just to get back to Jaquio again
* DemotedToExtra: Clones of the Malice Four, the bosses of the first game, appear as powered-down mooks in the second game.
* DifficultyByRegion: The NES version of ''III'' has no password feature, limited continues, less checkpoints and stronger enemies than its Famicom counterpart.
* {{Doppelganger}}: The Bio-Noid doppelganger from ''The Ancient Ship of Doom''
* DoppelgangerAttack: The Kelbeross beasts from the first two NES games, where only one of them was vulnerable but both were very, very deadly. Similarly, Ryu acquired this skill in ''The Dark Sword of Chaos'', where he could generate up to two Shadow Clones that are invulernable, would follow in his footsteps ''precisely'' (even stopping in midair if Ryu himself jumped and then stopped moving), and would slash or use Ninja Arts in perfect sync with him. A great deal of boss strategies (and speed runs) centered around proper positioning of these clones while Ryu himself ducked into a safe spot.
* DramaticThunder: The way that Ashtar introduces himself in ''The Dark Sword of Chaos''.
* DualWielding: Basaquer in the NES games dual-wields butterfly knives.
* EvilCounterpart: As far as the NES games go, it's explicitly stated that the [[TitleDrop Dark Sword of Chaos]] is this to the Dragon Sword, having been forged from a demon's bones as opposed to a dragon's fang.
* EvilTowerOfOminousness: Both the Tower of Lahja, and later the gate to the Chaos Realm, in ''The Dark Sword of Chaos''.
* FakeDifficulty: Aside from the famed birds and pits, there's also the fact that screwing up against the bosses in Level 6 of the first game will dump you at the start of the stage for no reason. Even if it's not a Game Over, and even though this hasn't been the way things work for the entire rest of the game. The fact that once you kill a boss it stays dead even after you hike it back there doesn't fully cover for how much of a dick move this is. The hit detection in all three of the games is also pretty awful. Ryu or pretty much any enemy can be hit, damaged or killed if their only pixels away from a damaging enemy or weapon, not when they, ya know, actually get attacked by said enemy or weapon. However, there are also points when you can clearly see Ryu's knife go through an enemy, but nothing happens to the enemy. This can make trying to make quick decisions or getting into tight spots much more of a pain, therefore leading to a fair amount of cheap deaths or injuries. A good example would be trying to avoid the stars flying ninjas throw at you in stages 5-3 and 6-2 in the first game. In the third game, this hit detection problem reaches bootleg game levels of bad. For example, if your on a platform, and a spike in a platform below comes near but is still many pixels away from your feet, it counts as a hit.
* FauxActionGirl: Irene, despite being a badass CIA agent, finds herself captured in both the first and second games. Played with both ways in ''The Ancient Ship of Doom'', which begins with Irene [[StuffedInTheFridge apparently murdered by a Ryu clone during the opening credits]] while spying on a secret lab. However, she later has a BigDamnHeroes moment when she rescues Ryu from the same clone with a machine gun.
* FourIsDeath: The Malice Four in the first NES game.
* GoodCannotComprehendEvil: Discussed at the end of the third game. Irene cannot comprehend evil, but Ryu can:
-->'''Irene''': I'll never understand why people make and pursue evil plans until they wind up dead.
-->'''Ryu''': Humans are always striving to achieve. [[BlindIdiotTranslation All of creatures on earth, in all worlds,]] can never be just a part of someone's plans. Fortunately, mankind is never foolish enough to wipe itself out to achieve some ambitions.
* HardLevelsEasyBosses: The first NES ''Ninja Gaiden''. Barbarian, Bomberhead and Basquer were all ridiculously easy once you got the pattern down, an easily-exploitable glitch could make Kelbeross a pushover, Bloody Malth is just a matter of getting close to him and mashing buttons and the Masked Devil just requires you to hit the giant orb in the middle. Jaquio, however, is ungodly hard, and the Demon is largely luck-based. The sequels evened it out quite a bit.
* {{Hellgate}}: ''The Dark Sword of Chaos'' presents a recursive example: an evil-looking tower with a demonic skull for an entrance, which leads to the antechamber of the Realm of Chaos. And inside ''that'', an altar upon which the actual gates can be opened.
* {{Hellhound}}: The Kerbeross beasts from the NES ''Ninja Gaiden'' and ''The Dark Sword of Chaos''
* HeroesWantRedheads: Irene was a redhead in the original trilogy. [[spoiler:As Sonia, [[EveryoneLovesBlondes her hair (supposedly bleached) is blonde]]]].
* HeroicSacrifice: Back in ''The Dark Sword of Chaos'', not only is it heavily implied that Robert died while [[HoldTheLine he held the line]] to protect Ryu's back, but ''the Dragon Sword itself'' makes a sacrifice to revive Irene at the end.
* HighlyVisibleNinja: How did the CIA and Jacquio's troops find Ryu so quickly after he came to America? Maybe it's because he's the only person in modern New York who runs around in broad daylight dressed like a Ninja.
* IKnowYoureInThereSomewhereFight: Ryu versus his brainwashed father in the first NES ''Ninja Gaiden''.
* {{Interquel}}: ''The Ancient Ship of Doom'' takes place after the events of the first NES ''Ninja Gaiden'', but before ''The Dark Sword of Chaos'', which is why Ryu still possesses the Dragon Sword, despite having lost it at the end. The Japanese manual makes the game's setting clear, but the American manual only implies it subtly.
-->After Ryu's victorious duel with Jaquio, Ashtar returned to the bowels of darkness and bided his time. But another evil creature was already on its way as another adventure awaits the unsuspecting Ryu Hayabusa...
* LedgeBats: The birds.
* TheLegionsOfHell: What will pour out of the Gate of Darkness to the [[{{Hell}} Realm of Chaos]] if Ashtar's ritual is completed. Many foes in the games already hail from there.
* LoveAtFirstSight: Both Ryu and Irene in the first NES game, after an entire adventure without any proper build up for romance. In fairness, Ryu took the fact he was able to meet her as a fitting payment for all the trouble they went through, and Irene seems to have the same mindset on this matter as she disregarded Foster's direct orders to kill him. The result is the couple kissing at the end; as of ''Dead or Alive'', they are HappilyMarried and running their Antique Shop together.
* TheManBehindTheMan: Jacquio --> Ashtar --> Jacquio. Trust us, ItMakesSenseInContext.
* MaskPower: Ashtar from ''The Dark Sword of Chaos'' wears a smooth, faceless metal mask with only thin slits for eyes... or maybe the eyes ''are'' part of the mask.
* NiceJobBreakingItHero: The NES games were fond of this. In the first, [[spoiler: Ryu leaves the statues together too long, releasing the Demon]]; a year later in ''The Dark Sword of Chaos'', [[spoiler: he doesn't pay attention as the pool of blood from Jaquio's corpse reaches the Sword of Chaos, releasing the Demon again]].
* NinjaPirateZombieRobot: [[AwesomeMcCoolName Funky Dynamite]], a man-sized mutant lizard cyborg with a jetpack and plasma guns.
* ObstructiveForeground: Used in ''The Dark Sword of Chaos'' intentionally, with infuriating results.
* OneWingedAngel: Jacquio in the first game, [[spoiler:Jacquio again]] in the sequel and Clancy in the final.
* PlatformHell: The NES games. If it wasn't bad enough that Tecmo forced you to use the wall cling ability and jump across tiny platforms over pits, they decided to throw in GoddamnedBats, eagles and even the ''grunts'' on full force. Worse, the first two games allow infinite {{mook}} respawns.
* PainfullySlowProjectile: Played straight in the NES trilogy, thank goodness. The PlatformHell aspect of the game is hard enough as is; it's almost NightmareFuel to think of what it would be like had the several enemies who shot at you or threw shuriken at you did so ''quickly''.
* PlayingWithFire: Most of Ryu's Ninja Arts in the NES trilogy revolve around flinging fireballs or encasing himself in them with the [[InvincibilityPowerUp Invincible Fire Wheel]].
* PrecisionGuidedBoomerang: The Windmill Throwing Star in the NES trilogy and the Windmill Shuriken in the two Xbox games.
* PuzzleBoss: In the Boss battle against Ryu's father, trying to strike him will get you nowhere. To win the fight, you have to destroy the statue casting orbs of energy towards him. (Which isn't hard, once you catch on. Or if you watched the cutscene right before the fight, which shows you what to attack)
* RaceAgainstTheClock: In Act 7 of ''The Ancient Ship of Doom'', should you make it to the FinalBoss without dying, you will notice the timer is '''very close''' to zero once you reach the end.
* RespawningEnemies: The NES trilogy has perhaps the most frustrating examples of such. After killing any mook, if their spawn point even goes ''one pixel'' offscreen and back, they're immediately back. In fact, the spawn points are so sensitive, you may find yourself at times standing in just the right spot for a spawn point to be grazing the boundary, causing them to ''infinitely respawn'' should you keep killing them without moving.
* RockBeatsLaser: Throughout ''The Ancient Ship of Doom'', instead of heading into a hellish dimension to battle demonic creatures like its preceding games, Ryu faces a high-tech robotic army at (mostly) artificial environments, culminating with a battle within an alien ship against a laser-equipped HumongousMecha.
* RuleOfThree: In the NES trilogy, each game requires Ryu to fight three bosses in succession in the final stage.
* SayMyName: In ''The Dark Sword of Chaos'', multiple times.
* SceneryPorn: The NES series had a fair amount of this as well: each game had at least one cutscene that was just a grand panoramic sweep that generally showed Ryu in the foreground gazing upon his uniformly majestic destination, and many of the backgrounds and stages were more visually detailed and attractive than the player was likely to notice.
* SchmuckBait: The Demon Statues from the first NES ''Ninja Gaiden''
* SingleStrokeBattle: The opening cutscene of the NES ''Ninja Gaiden'', where Joe gets defeated via this. [[spoiler: He later turns out to be alive...]]
* SleevesAreForWimps: Robert T. Sturgeon is a devoted follower of this philosophy.
* SpinAttack: The Jump and Slash Technique in the first game is a powerful art which turned Ryu into a flying buzzsaw and had the potential to take out bosses with one good hit. It's no wonder why it was removed in the sequels.
* StupidSurrender: In a cutscene in the first game, Ryu surrenders to a few CIA agents who point guns at him... right after finishing a level in which he had to defeat numerous enemies, including several of them who were armed with guns.
** Subverted, though, because with Dr. Smith dead and only a warning about the demon statues from him, Ryu didn't have anyplace else to go. He correctly surmised that going along with them would get him the information he needed.
* SwordBeam: The Dark Sword of Chaos can shoot off what looks like ball lightning.
* TeamPet: The Kelbeross are a villainous example, being Jaquio's pet dogs (well, they were before he mutated them into gargantuan monstrosities). This only gets described [[AllThereInTheManual in the manual]], though, leading people who didn't read it to consider them a GiantSpaceFleaFromNowhere.
* TrapDoor: The NES trilogy is loaded with this
* VisibleSilence: Made famous by the NES titles.
* WarmupBoss: Surprisingly, most of the early bosses in the NES games were this.
* [[OhCrap What the...?!]]: In the NES trilogy, this is Ryu's version of an OhCrap Moment. He tends to draw these like a moth to a flame.
** At the FinalBoss of ''The Ancient Ship of Doom'', Ryu instead stutters out the villain's name upon seeing its monstrous form.
* YourPrincessIsInAnotherCastle: After releasing Joe and defeating BigBad Jaquio, you still have to deal with the Demon he was trying to release. Much easier than the previous boss fight, fortunately.
* YouShallNotPass: Robert's battle against the demons in ''The Dark Sword of Chaos''.

[[folder:Tropes in the Team Ninja series]]
* AbsurdlySharpBlade: Played in an odd way in ''Ninja Gaiden 3''. Ryu's weapons can cut through metal, but not effortlessly − a good half of the [=QTEs=] in the game are button mashing to cut down turrets, spider tank legs or other armored equipment.
* AbsurdlySpaciousSewer: The tenth level of the Xbox title, oddly named "the Aquaduct" (sic).
** DownTheDrain: A sizeable chunk of the sequel's third chapter takes place in a sewer.
* ActionCommands: ''Ninja Gaiden III'' may be the first game to have these with ''non-indicative button prompts'' during steel-on-bone attacks. Even if you're told to press Y, pressing X works just fine, and vice-versa. Since steel-on-bone chaining works only if you press X, you'll sometimes be better off disregarding the button prompt. Of course, you can also just turn the button-prompts off entirely...
* AdvertisedExtra: Ryu's childhood friend Kureha gets her own short profile in the manual of the first game, indicating she'll have some important role. In truth, she only briefly shows up in one cutscene early on before dying alongside the rest of Ryu's village.
* AIBreaker: In ''Ninja Gaiden II'', midair attacks with the scythe. The Y button attack in particular ("Blood Rain") causes Ryu's landing to be delayed nearly a full second -- most enemies and even certain bosses will dash underneath you and get hit by the scythe.
* AlasPoorVillain: Genshin is from the rival Black Spider Ninja Clan who allied with Elizabet to resurrect the Archfiend, and sees Ryu as a WorthyOpponent. After multiple encounters that end with a stalemate, Genshin is formally defeated and reveals he was something of a pawn in the whole thing. Genshin is then revived as a fiend and defeated once more against Ryu with the True Dragon Sword, with Elizabet lamenting his uselessness. Ryu is subsequently enraged [[TakeUpMySword he picks up]] Genshin's sword The Blade of the Archfiend and uses it in conjunction with the Dragon Sword through the remainder of the game (it replacing the weaker twin swords "Dragon's Claw and Tiger's Fang" you previously had). Ryu then places Genshin's sword among [[WeaponTombstone the field of the buried warriors]].
* AndYourRewardIsClothes: Beating any of the difficulty levels in the modern games rewards the player with a new costume.
* AntiFrustrationFeature: ''Ninja Gaiden III'' allows the player to switch anytime to "Hero Mode". The game plays the same as on Normal difficulty, but when health is under 30% (when the lifebar starts to glow red), guard and evading become automatic, making death pretty much impossible.
* ArtifactMook: In the first level, Murai sends his own, novice mooks at you in normal mode. From hard mode on, though, the same level makes you fight Black Spider Ninja... which are supposed to be enemies of Murai and have no reason to obey him whatsoever. Similarly, in hard mode you will often fight fiends and Black Spider Ninja altogether, even though these fiends are supposed to fight the Ninja, not help them.
* ArtificialStupidity: In ''II'', the Werewolf fiends cannot get on a table if Ryu jumps on it. A patch made things even more stupid, with the Werewolf fiends able to get on it but not get ''off''. The T-Rex boss in ''Ninja Gaiden III'' is becoming quite infamous for this. One of its main forms of attack is charging Ryu and then suddely tripping and falling to its side without hitting anything just so Ryu can attack it.
* AscendedExtra: Some of the characters, bosses, and even ''mooks'' get this in the sequels and [[UpdatedRerelease Updated Rereleases]].
* AutoRevive: Talisman of Rebirth in the modern trilogy
* AwesomeButImpractical: The Unlabored Flawlessness in the Xbox ''Ninja Gaiden''. It's the wooden sword upgraded some 7 times (other weapons peak at 3 or 4) with no discernable change until it becomes a giant wooden paddle. It's a surprisingly powerful weapon, able to wreak havoc at about the same power as the upgraded War Hammer, but its high upgrade cost and very restrictive secret to its power ([[CriticalStatusBuff when you're low on health]] [[DesperationAttack it becomes exceptionally vicious]]) makes it difficult to use.
** The Falcon's Talons from ''Ninja Gaiden II'' and onwards is generally regarded as having one of the worst Ulimate Techniques to use (the talons themselves are very restrictive to close combat), but it's awesome to see Ryu go berserk on an enemy with claws attached to his hands and feet.
** Projectile weapons in the first Xbox game start bouncing off enemies when you get near the end (so much for your giant shuriken and stocks of gunpowder laced kunai). The bow is an exception, but standing around for Ryu to take it out and fire gets you killed pretty quickly at higher difficulties, though it's made more useful in "Sigma Plus" as you can now shoot arrows while jumping.
* BackFromTheDead / DisneyDeath: Ryu after being killed by Doku in the Xbox ''Ninja Gaiden''.
* BagOfSpilling: In the modern trilogy, this is averted for Ryu's movelist. The Flying Swallow, Izuna Drop, counter and Guillotine Throw are all unlocked at the start of ''II'', all of which were acquired during the first game. Played straight for the weapons in a strange way: three of them that are found in random places ([[SimpleStaff the Lunar]], [[DualWielding Dragon's Claw & Tiger's Fang]] and the [[FightingWithChucks Vigoorian Flail]]) were already acquired in the first game, [[FridgeLogic of which two of them are supposed to be unique…]]
* BeamSpam: Dagra Dai in ''Ninja Gaiden II''
* {{BFS}}: Aside from playable examples, cleavers are used by Fiend Nightmares and Spirit Doku has one long nodachi in the Xbox ''Ninja Gaiden''.
** The final boss in the unjustly-overlooked arcade original had a pair of these.
** Dagra Dai {{Dual Wield|ing}}s these.
* BigBad: The Regent of the Mask [[spoiler: and [[TheManBehindTheMan men behind the man Cliff and Ashtear,]] in ''Ninja Gaiden III'']]
* BlockingStopsAllDamage: One boss explodes. The way to avoid damage is to block it. This leads to a massive arena-wide explosion stopped by a katana.
* BloodierAndGorier: ''Ninja Gaiden II'' for the 360 ([[SerialEscalation as if the first wasn't gory enough...]]). ''III'' more or less goes back to the level of the first game by removing dismemberments and decapitations entirely, although thanks to a new graphical engine, HighPressureBlood will not only stain Ryu's weapon during fights, but also his body [[CameraAbuse and the camera]]. However, ''Razor's Edge'' brings back all the gore that made ''Ninja Gaiden II'' (in)famous.
* BoringButPractical: For the array of awesome weapons that you have stashed in {{Hammerspace}}, you'll probably end up being forced to use the Dragon Blade to beat bosses and higher-tier enemies.
** To a lesser extent, shurikens do virtually no damage but are very useful to stun small enemies and prevent them from grabbing you or interrupting your charge for an Ultimate Techqniue.
* BossInMookClothing: Good Lord, the Vigoorian Berserkers. They are armed with a [[{{BFS}} Dabilahro]], [[LightningBruiser are fairly fast for their build]], [[ImplacableMan have a solid guard but are also very resilient]], and on top of that have nothing but powerful close range ''and'' distance attacks. Of course if you try to use a Flying Swallow, [[KungFuProofMook you will be promptly dissuaded]] [[HoistByHisOwnPetard to try again]]. Manage to deal them enough damage? To reward you, they [[TurnsRed turn red]] and become even more dangerous. Granted, there is a simple tactics to take them down (let them attack at close range and use a counter) [[TheComputerIsACheatingBastard but it doesn't work so well when there are two or three of them]] (which is, 90% of the time).
** Alchemists in ''Razor's Edge'', always attack in groups of 3, just love to dodge your attacks and spam {{Painfully Slow Projectile}}s on you while you're trying to focus on one of them. They can also block your Ninpo and steel-on-bone attacks with their alchemic shield, and have a grab that drains both your health ''and'' your ki.
* BossRush: Sort of at the end of the first Xbox ''Ninja Gaiden''. You first fight two previously beaten bosses, then Marbus, two forms of Vigoor and finally the BigBad. At higher difficulties, [[OhCrap the two fairly easy bosses are replaced by the]] ''[[OhCrap much]]'' [[OhCrap more challenging ancient fiends Nicchae and Ishtaros]], making this a BossRush with only new bosses.
* {{Bowdlerise}}: While ''Sigma 2'' brought great additions such as new playable characters, game modes and a multiplayer option to warrant its deserved critical acclaim, it also got some vocal criticism from some due to the direction of removing the potential bloodbath present in the 360 version. Rather than see gallons of blood, dismembered limbs and body parts were turned into purple mist, which creates a rather odd effect because Ryu still performs brutal actions against enemies, only to see them gush out purple-colored smoke.
* BraggingRightsReward: In ''Ninja Gaiden (Sigma)'' for the Xbox/[=PS3=], the Plasma Saber MK II (on Normal) or the Dark Dragon Blade (Hard and above), sort of. You get them by gathering all 50 gold scarabs, but the latter is so close to the end of the game that they won't be of much use. Add to this that you have to bring the scarabs to Muramasa, and since there's no shop at the top of the Emperor's tower (where you get the last scarab), that means you have to go backtrack through tough enemies and swarms of [[DemonicSpiders ghost piranhas]] just to find a shop where you can get the damn sword. You then discover the Plasma Saber is every bit identical to the True Dragon Sword and that you can't use the Dark Dragon Blade against the FinalBoss ([[spoiler:since he's the one using it]]). With the exception of some fiend challenges like the ones with many {{B|ossInMookClothing}}erserkers, it's not really worth the trouble. This trope is averted with the highest difficulty Master Ninja Mode, which rewards you with...nothing!
** The Unlabored Flawlessness can be viewed this way. Its most notable feature is that its attack power goes way up when your health is in the red zone, but if your defense is skilled enough to survive like that, you probably don't need it.
* BreakingTheFourthWall: In ''Dragon Sword'', after finally explaining what the collectable Wooden Amulets are for, [[TeenGenius Denroku]] comments that he read it in the strategy guide.
* BrutalBonusLevel: The final mission in the first game, Eternal Legend, is a mini-scenario with 5 phases, during which you face waves of all the enemies met in story mode, and several bosses in-between. You have access to most of your semi-upgraded weapons and unlimited projectiles. You can save and go shopping between phases, but you will have ''very'' limited resources, and will have to take as little damage as possible to beat the mission.
* BulletHell: ''Ninja Gaiden II'', Master Ninja mode. Just… [[http://www.youtube.com/watch?v=AvTPjdTRfH4 watch.]]
* CallBack: In Day 6 of ''Ninja Gaiden 3'', the Epigonos boss can switch between a sword, a scythe, and claws, like Ryū. Except the combos he uses with the scythe and claws are from the movelist of ''Ninja Gaiden II''.
* CameraAbuse: For additional immersion, blood will splat on the screen each time you peform an Obliteration Technique on an enemy in ''Ninja Gaiden III''.
* CameraScrew: In the modern trilogy, specifically the ones released on Microsoft platforms, the camera will often be your toughest opponent, chosing the most impractical angle possible, zooming in without reason and putting {{mook}}s or even Ryu himself off-screen. Surely ''Sigma'' and ''Sigma 2'' have fixed this problem, haven't they? Er...well, no.
** Fortunately, the camera in ''Ninja Gaiden III'' does its job decently, although still not perfectly. The most frequent problem is that enemies in the foreground obstruct your view because of the low camera angle.
* CatsAreMean: And those of the first Xbox game are DemonicSpiders!
* ChainsawGood: Spriggans (zombies in ''Ninja Gaiden II''/''Sigma 2'') with chainsaws and cannons for arms
* ChargedAttack: Hold-type, though a variation. To pull off the devasting Ultimate Techniques in the modern games, you must collect essences by holding down the heavy attack button in the first Xbox ''Ninja Gaiden''. The sequels and remakes allowed the techniques to be performed even if essence isn't collected, but it will kick in much faster if essence is absorbed.
** ''Ninja Gaiden III'', however, opts out into the collect-type: you can only unleash an Ultimate Technique when Ryu's arm starts to glow red after killing {{mook}}s. In the same vein, Ninpo can only be activated if a gauge is filled up.
** And ''Razor's Edge'' goes back to a mixed-system, even adding a third level of charge.
* ChargeMeter: Ryu glows brighter and more fiercely as the charge of an Ultimate Technique increases (accompanied by an explosion).
* CheckPointStarvation: ''Sigma 2'' has a few passages where you have to go through several long, tough fights without the possibility to save in-between, most notably the last parts of Chapter 13 (including the very grueling stairway fight), 14 (the graveyard fights) and the first half of Chapter 16 (the very long straight corridor). The latter two have an appearance of {{Recurring Boss}}es out of nowhere without the usual auto-save. These passages are stressing in Normal but get ''really'' sadistic in Master Ninja.
* CherryTapping: [[http://iberiansngrealm.com/Wooden_Sword.html Wooden Sword School]]
* ChestMonster: [[MemeticMutation We found some ghost fish - in a chest! Instead of a box of "cash"!]]
* CollapsingLair: A staple of the series once the BigBad [[LoadBearingBoss is defeated]].
* CompetitiveBalance: Weapons in the modern trilogy use some combination of [[NecessaryDrawback range, damage, combo potential and the power of the Ultimate Technique]]. The Dragon Sword is the most balanced but in the first game there are several weapons that mostly play the same way (War Hammer, Dihilabhro and the Unlabored Flawlessness are all heavy blunt weapons, as well as the Dark Dragon Blade in bonus-quests). The sequel has a bit more variety in that regard, since no two weapons play quite the same.
** Also used for the girls in ''Sigma 2'': Rachel is the MightyGlacier, Ayane the FragileSpeedster, while Momiji's a JackOfAllStats.
* ConservationOfNinjutsu: Ryu, a lone {{ninja}}, will slice his way through veritable armies of {{mook}}s.
* CounterAttack: A basic technique in the modern games, although it has been progressively {{nerf}}ed. In the first game, it was overpowered (especially if used with the [[{{BFS}} Dabilahro]]), but in the sequel they mainly served to dismember weaker enemies. By ''Ninja Gaiden III'', it's just a little more damaging than a heavy attack. ''Razor's Edge'' un-nerfs it by giving it back its dismembering properties.
* CosmeticAward: Karma system. Averted in ''Razor's Edge'', wherein the player spends points to upgrade weapons/Ninpo, increase health and learn new techniques.
* CrueltyIsTheOnlyOption: ''Ninja Gaiden III'' has sequences where you're forced to slowly descend on helpless, disarmed {{mook}} and mercilessly cut them down. While the first instance is a {{mook}} who just watched you dozens of his comrades and drops his gun, pleading for his life (and scared shitless), other situations has the {{mook}} dare you to kill them while [[BreakingLecture lecturing you]]. The game cannot progress unless you kill them. [[IncrediblyLamePun Mercifully]] removed in ''Razor's Edge.''
* DamnYouMuscleMemory: In ''Sigma 2'', the bow is aimed and fired with the triggers instead of the face buttons for ''Ninja Gaiden'' and ''Ninja Gaiden II''. Justified since it allows to throw shurikens even with the bow equipped but it does take a bit of time to get used to it. The opposite is even worse: in ''II'', many ''Sigma 2'' players will try to throw shurikens mid-jump and fire an arrow; it won't work.
** Same deal with guarding: for the Xbox games, it's on the left trigger; on the [=PS3=], it's L1. Consider the consequences of letting your guard down for one second in ''II'', this can be a problem.
* DeadlyLunge: The Flying Swallow and Guillotine Throw techniques can make short work of the standard Mooks.
** A lot of enemies like to pull these stunts too.
* DeathFromAbove: A gameplay mechanic in ''Ninja Gaiden III''. You can jump from a high building and [[ArtisticLicensePhysics glide in the air]] towards a poor mook, before impaling him as you land.
* DeathOrGloryAttack: ''Razor's Edge'' turned the stee-on-bone attacks into this. If you time it right, you can one-hit-kill an enemy before he grabs you − and repeat the attack on nearby enemies (a max-upgraded allows up to 4 kills in a row), and regain a tiny bit of health. If you don't, well, [[CaptainObvious he grabs you]].
* {{Doppelganger}}: The aggressive Doppelganger Fiends in the modern series. They are capable of doing nearly every single one of Ryu's moves and every single advanced techniques a player ''must'' know.
** The Epigonos from ''Ninja Gaiden III'', and it comes in two forms: the first has Ryu's form, the second has a fiendish transformation and can switch between three weapons like Ryu. However, they're not as aggressive as the fiend versions and they easily fall for an Izuna Drop, even in harder difficulties.
* DoppelgangerAttack: The Doppelganger Fiends.
* DualWielding: A wide assortment available for Ryu, ranging from the Dragon's Fang and Tiger's Claw, Tonfas and the [[spoiler:True Dragon Sword and Blade of the Archfiend]].
* EarnYourFun: Itagaki wasn't the page quote for nothing.
* EasyModeMockery: Done literally in ''Black''. You unlock Ninja Dog mode if you die too many times on the first level, but not before Ayane admonishes you for being so weak. She then proceeds to give you a purple ribbon powerup, and all the power bracelets become ribbons as well. Ryu remains in his purple ninja trainee outfit for the remainder of the adventure after Chapter 2 instead of changing to his [[IconicOutfit iconic Black Falcon suit]].
** In ''Razor's Edge'', playing in [[AntiFrustrationFeatures Hero Mode]] reduces the experience earned in combat ''if'' the character's health drops to the level where guard becomes automatic (i.e. you would have died without it). Hero Mode was also featured in ''Sigma Plus''
* ElaborateEqualsEffective: Used for every weapon in the modern trilogy, except for katanas. In a variation, [[spoiler:the True Dragon Sword and Blade of the Archfiend]] replaces a maxed-upgraded Dragon's Claw and Tiger's Fang in ''II''/''Sigma 2'', since it's the strongest weapon in the game.
* ElevatorActionSequence: Rachel's chapter in ''Sigma 2'' has one of these.
* EliteMooks: The Underworld versions of the Incendiary Shuriken ninja deal much more damage than their normal counterparts who were already [[FakeDifficulty cheap enemies]], but they also feature a quasi-suicidal attack where they stab you in the chest with one of their claws and then detonate an Incendiary Shuriken attached to their impaled-arm to deal massive damage.
* EpicFlail: Nunchaku, Vigorian Flail and Kusari-Gama. The latter two crosses with SinisterScythe.
* EscortMission: A very brief, easy one at the end of Day 4 in ''Ninja Gaiden III'', where you have to protect Canna as multiple Homunculi jump and attack you. Inverted in the same game during the trek to find Joe, as Momiji is the one escorting Ryu.
* EssenceDrop: In the modern games, yellow essence is the currency, blue refills health and red restores Ninpo. In fact, this trope is a requirement to perform Ultimate Techniques in the first game. ''Ninja Gaiden III'' removed it completely for a better GameplayAndStoryIntegration.
* EverythingsBetterWithDinosaurs: LOA's various activities include cloning dinosaurs to sell them as pets, or so says the Regent of the Mask; not sure many people will want a Tyrannosaurus Rex at home.
* EverythingsBetterWithSpinning: Nearly the entire weapon roster in the latter-day Gaiden games abuse the hell out of this. Of particular note is the [[SimpleStaff Lunar]], which Ryu mainly uses by spinning it so fast it literally grinds his enemies' limbs off.
* ExcusePlot: Primarily a trait of Itagaki's games, which can both be summed up as "BigBad attacks the village, Ryu chases BigBad to his lair and defeats BiggerBad". Both [[UpdatedRerelease Sigmas]] and ''Dragon Sword'' are a tiny bit more fleshed out. ''Ninja Gaiden 3'', however, is much more plot-driven, going back the tradition of the NES games.
* ExpospeakGag: In the middle of the "Flying Fortress Daedalus" level in ''Ninja Gaiden II'', the intercom voice suddenly stops being serious for a second.
--> ''"Another intruder has been detected with explosives. A blonde woman. Message to all units: [[DistractedByTheSexy she's hot!]]"''
* EyepatchOfPower: Genshin
* TheFaceless: [[spoiler:Kasumi]] in ''Sigma 2''
* FacelessGoons: [[http://www.youtube.com/watch?feature=player_embedded&v=2hYya_IyS1k Averted]] in ''Ninja Gaiden III'' for a full dollop of WhatMeasureIsAMook.
* FakeDifficulty: The {{Camera Screw}}s were bad enough in the first Xbox game, but the second added some extremely cheap mooks, always in hordes, who have grabs that are way too fast to anticipate, or ones who constantly spam explosive projectiles, mostly from off-screen. Mentor and Master Ninja Modes often takes this straight into BulletHell.
* FatalFamilyPhoto: As soon as the scientist in ''III'' starts talking about how Canna reminds him of his daughter back home, whom he will be seeing soon, you know he's doomed.
* FauxActionGirl:
** In the Xbox ''Ninja Gaiden'', Rachel, who kills a random fiend when she's introduced, spends the rest of the game getting captured, thrown around Vigoor and being strung up for a sacrifice. Lovely outfit, however. This gets fixed in ''Sigma'', where she's promoted to playable character, thus promoted to full-on ActionGirl. Who still gets constantly captured and thrown around in the {{cutscene|Incompetence}}s. Aside from the promotion, her role in the story didn't change.
** Sonia in ''Ninja Gaiden II'', plays the badass CIA agent a little more convincingly. While she manages to get captured and needs rescuing at the start, she repays the favor by showing up like a {{big damn hero|es}} and saving Ryu from a battle against impossible odds, and later by strolling around the Daedalus, casually dispatching ninja {{mook}}s with a rocket launcher. Unfortunately, she gets demoted by getting captured ''again'', put into a dress marginally ''less'' {{Stripperific}} than her regular attire, and fails to do anything useful from that point on (although admittedly, it's kinda hard to do anything [[spoiler: in the Underworld]] if you're not a badass {{Ninja}}.
** Really, the series has become a FauxActionGirl ''factory,'' since [[ThirdPersonSeductress hot, playable female characters]] have become a selling point, but the protagonist is always Ryu, requiring 1-3 seemingly-competent women to still need him bailing them out every game.
** Come in, Mizuki [=McCloud=], and welcome to the club!
** As stated above, some of the female characters manage to abandon the FauxActionGirl category eventually. The best example is Momiji, who gets captured in ''Dragon Sword'', but gets to be a full-blown ActionGirl in ''Sigma 2''. And by the time of ''Ninja Gaiden III'', she spends a whole level [[BackToBackBadasses fighting alongside Ryu]] almost as an equal.
* FetchQuest: The golden scarabs in the first Xbox ''Ninja Gaiden'' and the crystal skulls in the sequel, though the latter's especially bad: when you collect the 30 skulls, the reward is...a giant crystal skull that has no use whatsoever. It ''might'' have some sort of effect, but the description of the object is too crytpic to determine what.
* FieldOfBlades: In ''II'', the last part of the infamous [[MarathonLevel Chapter 11]].
* FinishingMove: Obliteration Techniques, Fiend Sealer and variants
* FlashStep: Several Ultimate Techniques emulate this; in the sequel, most Ultimates rely on this to continue the attack. The True Dragon Sword's Ultimate Technique upgrades this into TeleportSpam.
* FlunkyBoss: Masakado and Marbus in the first Xbox ''Ninja Gaiden'' and Zedonius and Dagra Dai, as well as the second fights against Rasetsu, Genshin and Volf in ''II''. In ''Black'', ''Sigma'' and ''II'', [[OhCrap every single boss turns into this in higher difficulties]].
* FranchiseZombie: Itagaki wanted ''II'' to be the last ''Ninja Gaiden'' game, at least for modern continuity. It only took his departure for Hayashi to keep going with ''III''. Still, it's unclear if Itagaki [[LikeYouWouldReallyDoIt really meant that]], since he made the statement when he was already at odds with Tecmo Koei, very close to his eventual departure.
* FrickinLaserBeams: Paz Zuu from the Xbox ''Ninja Gaiden'' uses EyeBeams which, oddly enough, doesn't damage you directly; instead, it traces a path, which ignites shortly afterwards. Unfortunately, the black pincer fiends in the same game aren't so kind-hearted with their own EyeBeams, [[DemonicSpiders infuriating more than one player]].
* GameplayAndStoryIntegration: ''Ninja Gaiden III'' makes a point of eliminating elements that "break the immersion". No HyperspaceArsenal (Save for the extra weapons in ''Razor's Edge'', but that's it), no statues that teleport you to a shop, no EssenceDrop from dead foes and the save point statues are replaced by a falcon following Ryu. There are no healing items either: even in ''Razor's Edge'', all methods for healing (Ninpo, meditation, steel-on-bone and save points) are performed directly in-game, except for life-upgrades.
* GiantSpaceFleaFromNowhere: The ankylosaurus at the end of ''Ninja Gaiden II'' Chapter 7 would seem to fit, but it's actually seen and referred to at least once before you fight it. The two you eventually face in the Underworld, however, fit this trope.
** Actually, you can see them in a lake of lava a little ways before the second fight.
** Really, a good portion of the minibosses fit this. The Rasetsu-class ninja show up in the oddest of places...
** The most egregious example in ''II'' is the electric metallic Viking/fish/sperm… [[NinjaPirateZombieRobot thing]] at the end of Chapter 3.
* GoodThingYouCanHeal: One of the new techniques of ''Razor's Edge'' is "Meditation", which allows you to heal yourself using your Ninpo energy.
* GrenadeLauncher: Certain MSAT {{mook}}s in the first Xbox ''Ninja Gaiden'' carry these, and ''Black'' gave the tanks these to counter an easy means of defeating them, which was to get so close that it could only circle without being able to fire its cannon, only a mounted machine gun with a suppressable gunner.
* HarderThanHard: Very Hard/Path of the Mentor and Master Ninja/Path of the Master Ninja.
** ''Ninja Gaiden II'' was this on any difficulty...[[TheComputerIsACheatingBastard for questionable reasons]].
** Players who became proficient on Path of Acolyte/Warrior would end up dying in the first chapter of Path of the Mentor. All enemies are upgraded to those you previously encountered later on and you start out with no upgrades.
* HardLevelsEasyBosses: This is also the case in ''Ninja Gaiden II'': while the levels are basically massive gauntlets with endless hordes of cheap {{mook}}s, most bosses are surprisingly easy to take down. Even the four Greater Fiends and the FinalBoss pose little threat. ''Sigma 2'' balanced things by reducing the amount of on-screen {{mook}}s but made most of the bosses harder, improving their AI and health.
** Played straight in Ayane's chapter in ''Sigma 2'', though; Onibaba is considerably easier than the mooks you have to get through first, particularly at higher difficulty levels.
* HeelFaceTurn: [[spoiler: Awakened Alma saving Rachel]]
* {{Hellgate}}: Mt. Fuji is one, apparently.
* HeroicSacrifice: [[spoiler:Awakened Alma saving Rachel]]
* HeadsIWinTailsYouLose: The first fight against the Regent of the Mask in ''Ninja Gaiden III''. You stab him for what seems to be the finishing blow...but instead he grabs Ryu's sword, utters a few words to activate the Grip of Murder and fuses it into his arm, giving him a cursed RedRightHand for the rest of the game.
* HighPressureBlood: While ''Ninja Gaiden II'' went for LudicrousGibs, ''III'' took this route.
* HopelessBossFight: Two of them in ''Ninja Gaiden Sigma''. In Chapter 2 against [[spoiler:Doku]], when you have only a level one Dragon Sword and a rachitic lifebar, and in Chapter 14 with Rachel when you fight [[spoiler:Nicchae and Ishtaros]]. In both cases, a normal player will likely get their ass handed before understanding what's going on. It ''is'' technically possible to win, but that requires insane skill, and even if you do [[GameplayStorySegregation your character gets beaten in the cutscene anyway.]]
* HowWeGotHere: The original ''Ninja Gaiden III'' begins with the scene from the very first trailer of the game − a first-person perspective of Ryu coldly assassinating an enemy and removing his mask, with chaos in the background. The player gains control of Ryu as he fights a giant humanoid monster, before the title appears and the story flashes back to Day 1. [[spoiler: Turns out the man Ryu is killing is Theodore Higgins, BrainwashedAndCrazy into becoming the Regent of the Mask, and the giant monster is the Goddess using Theodore's daughter Canna as its vessel, wielding the Dragon Sword]].
* HyperspaceArsenal
* IdiosyncraticDifficultyLevels: In ''Ninja Gaiden II'', the difficulty runs from Acolyte, Warrior, Mentor to Master Ninja.
* IHaveAFamily: One of the {{mook}}s tries to pull this on Ryu at the beginning of ''Ninja Gaiden III''. [[CrueltyIsTheOnlyOption It works as well as expected.]]
* ImmuneToBullets: Many higher-level {{mook}}s in the modern trilogy are immune to standard shuriken or can block them if you throw them off-the-cuff instead of as part of a combo. In the weapon description of Rachel's sidearm in ''Sigma 2'', it states high-level fiends are immune to her magic-laden ammunition, crafted specifically to give her an edge in fighting them.
* ImperialStormtrooperMarksmanshipAcademy: Averted in the modern games. Gun-toting enemies are very competent at aiming and can be a real hindrance. The only exceptions are the basic hooded {{mook}}s of ''Ninja Gaiden III'', who consistently shoot over your head, even when you're kunai-climbing a wall and you are not meters from them.
* ImpossiblyCoolWeapon: Plenty, such as the Vigoorian Flail, but in RealLife it would be more dangerous for the user than the target. It probably wouldn't swing as easily as a nunchaku, either. Then there's the Plasma Saber MK II. Most projectiles are also this, such as the Incendiary [[InsistentTerminology Kunai]], the FuumaShuriken, the Gatling Spear Gun and Howling Cannon.
* IndyEscape: ''Ninja Gaiden III'' is quite fond of these, with notably two in Day 3 (the first to escape a napalm bombing, the second to outrun the T-Rex). Thankfully, it doesn't have too much of the {{Camera Screw}}s these sequences usually have, since the camera zooms out a bit when an obstacle is close.
* InfiniteSupplies: Ryu has an endless supply of standard shuriken. Enemies with small arms have to periodically reload (most evident with the MSAT), but they never run out of magazines.
** In ''Sigma 2'', he also has an infinite amount of arrows. In the first game and ''II'', there's a limit, but there will always be a body bristling with arrows nearby when you need it.
* InstantDeathRadius: The modern trilogy have the Gleaming Blade move and its Ultimate Technique versions, which eat {{mooks}} for breakfast.
* {{Invisibility}}: The Ghosts in ''Ninja Gaiden III'' have an invisibily suit and will usually use it for surprise attacks or lob grenades at you from every direction. You can detect them with your shurikens and your bow, and they always turn visible when they attack, so they aren't ''that'' difficult to fight, but they still can be a pain at higher difficulties.
* InvulnerableAttack: Ninpo, off-the-wall attacks, throws, Obliteration and Ultimate Techniques, and steel-on-bone in the modern series (plus certain spin attacks in ''Ninja Gaiden II''). In the higher difficulties of ''II'', knowing how and when to use these is actually crucial.
* JigglePhysics: Itagaki is very fond of this in his games. ''Sigma 2'' gives us the ability to control this with the Sixaxis controller.
* JumpPhysics: Remember, kids -- you can change directions and accelerate multiple times while mid-air, and maintain yourself in the air by maiming an enemy!
* KaizoTrap: The giant armadillo boss in ''Ninja Gaiden II'' explodes after death, which kills you instantly. The only way to avoid a OneHitKO is to hold the block button, which is rather counter-intuitive since no other explosive attack in the modern series can be blocked.
** The clawed mutants of ''III'' will sometimes start to "overheat" and come at you to explode after you killed them.
* KickThemWhileTheyAreDown: Fiend-Sealer from the Dragon Sword in the Xbox ''Ninja Gaiden''. Notched up in sequels with Oblieration Techniques.
* LagCancel: You can throw a shuriken to cancel the recovery of normal attacks (but not heavy ones). ''Razor's Edge'' also introduces the [[NoIAmBehindYou Cicada Surge]], which can be activated any time, including in the middle of a combo, as long as you are on the ground. Both techniques require quick thinking and good reflexes to use effectively.
* LargeHam: Volf, all the way. The Regent of the Mask in ''Ninja Gaiden III'' takes his share, too.
* LethalLavaLand: The underworld in ''II'', which can be accessed by leaping into Mount Fuji.
%%* LeParkour
* LifeDrain: A special ability of Kitetsu, Doku's demonic sword in the first Xbox ''Ninja Gaiden''. You can do it to minor {{mook}}s the same way Doku does it to you and regain quite a bit of health. You can even do it to ''Doku himself''. However, the rest of the time you use it, the blade drains ''your own health''. In ''Sigma'', holding the sword doesn't deplete your lifebar, but the effect of this trope is considerably {{nerf}}ed.
** The Alchemist {{mook}}s in ''III'' also have a grapple maneveur like this.
* LighterAndSofter: ''Ninja Gaiden Sigma 2'' when compared to the original ''Ninja Gaiden II'', graphically speaking. Most of the blood and gore is removed and it uses noticeably brighter color tones and a bloom effect, thankfully the Vita version - ''Sigma Plus 2'' restored all the gore.
* LivingStatue: In ''Sigma 2'' you fight a giant Buddha statue as a WarmUpBoss; a few chapters later, ''the freaking Art/StatueOfLiberty''.
* LoadsAndLoadsOfLoading: An issue in ''Sigma 2''. For example, you have a loading at the chapter screen, then if you want to change costumes you have another loading, and after you've selected the outfit, you have to go through the chapter screen loading ''again''. In ''Ninja Gaiden III'', the "world map" animation would be cool if it wasn't so long and if you didn't have to watch it every single time you load the game or get to the next day. Sometimes you even have to watch it ''twice'' between two events.
* LudicrousGibs: Every weapon in ''Ninja Gaiden II'' can dismember and dice opponents, [[OnlyAFleshWound not that this deters them from fighting]]. Lycanthropes will even pick up stray body parts and throw them at you.
* LosingYourHead: Inverted with the zombies and Spriggans in the first two modern games. They continue their attacks even after being decapitated, although doing so renders them blind and they just swing randomly. The flare fiends in ''Sigma 2'' can also fight headless, and they are ''not'' blinded.
* LostTechnology: Twin Serpents Plaza statue in the Xbox ''Ninja Gaiden''/''Sigma''
* MacrossMissileMassacre: Thanks to some {{BFG}} toting ninjas in the later levels of ''Ninja Gaiden II'', you get to be on the receiving end of these.
* MagikarpPower: The Wooden Sword is pathetic until its final upgrade, where it becomes the Unlabored Flawlessness, a potential gamebreaking weapon for those skilled enough to use it.
* TheManBehindTheMan: Doku -> Vigoorian Emperor -> [[spoiler:The Dark Disciple, who is Murai in disguise]]
* MarathonLevel: Many in the first Xbox game, notably those with long puzzles. In ''Ninja Gaiden II'', nearly every single chapter is this, but Chapters 6, 8 and 11 are the most notable, especially the latter.
* MaskPower: Inverted with the Ogres from ''Ninja Gaiden Black'', who grow stronger after Ryu breaks their masks.
* MegaCorp: Lords Of Alchemy in ''Ninja Gaiden III''
* MercyKill: One of the developers of ''Ninja Gaiden II'' described Obliteration Techniques as this, but considering dismembered {{mook}}s still go after you and will occasionally [[TakingYouWithMe use a suicidal maneveur]], "mercy" might be overstating it.
* MercyMode: Ninja Dog in the first Xbox ''Ninja Gaiden'', Hero Mode in ''III''
* MetaPowerUp: You can purchase a power-up in ''Razor's Edge'' (possibly [=NG3=] as well) that allows you to accumulate Karma more quickly.
* MightyGlacier[=/=]StoneWall: The purple zombies of the first Xbox ''Ninja Gaiden''. They carry enormous bayonet guns, their attacks are pretty damaging, but are so slow you have to be really careless to get killed. It takes three full Ultimate Techniques of the Unlabored Flawlessness to make them bite the dust, meaning they have more health than some ''bosses''.
* MookBouncer: The black laser fiends in the first Xbox game are already [[DemonicSpiders annoying]], but in the tower section of the second-to-last chapter, they can use a really nasty grapple that drags you underground and sends you back to the level below, forcing you to go through the previous wave of enemies again ''and'' through a wave of ghost fish. Even more infuriating if you're doing a [[SelfImposedChallenge Karma run]], since it prevents you from getting any more points in that fight (it's counted as if you had fled the fight).
* MookChivalry: [[AvertedTrope Chiva-what]]?
* MookDebutCutscene: Generally averted in the modern trilogy, with a few exceptions like the [=MSATs=], the zombies and the flare fiends in ''Ninja Gaiden''/''Sigma'', or the Van Gelfs in ''II''/''Sigma 2''. In both cases, the "rank" of the enemy introduced will actually change depending on the difficulty: a purple (immature) Van Gelf will come out of the hole in Accolyte, a green one (winged) in Warrior and a golden one (the strongest type) in Mentor.
* MoraleMechanic: In ''Ninja Gaiden 3'', using the fire dragon Ninpo will cause the weakest enemies around to drop their weapons, cower and beg for their lives. If you so chose, you can finish them off regardless.
* MostDefinitelyNotAVillain: Murai starts off the first Xbox ''Ninja Gaiden''/''Sigma'' by sending dozens of his men at you to be killed. Throughout the game, he sends you letters encouraging you kill as many people as you can, including civilians, because their blood will make the Dark Dragon Blade stronger. Yeah, good luck guessing who the "surprise" FinalBoss will be.
* MultiMookMelee: The so-called Fiend Challenges in ''Ninja Gaiden''/''Sigma'' and the Tests of Valor in ''II'' (but removed in ''Sigma 2'') and ''Razor's Edge''. ''II''/''Sigma 2'' has infamous stairway fight in Chapter 10/13, where you face a ridiculous number of enemies at the same time and take down a good hundred of them. Hell, in Master Ninja Mode for ''II'', the game is pretty much a 12-hour long MultiMookMelee!
* PowerCopying: Weapons picked from certain bosses will allow Ryu to perform their special attacks.
* MysteriousWatcher: Ayane and Gamov from the Xbox ''Ninja Gaiden''
* {{Nerf}}: The Flying Swallow in the Xbox game was toned down in ''Black'' because you could spam it on pretty much everything with 100% success. ''Black'' featured {{mook}}s that were specifically designed to punish you for overabusing it, i.e. block the attack entirely and counter it. You definitely didn't want to be caught using that on the Advanced MSAT soldiers.
** The counter system: in the first game, counters were fairly easy to execute with little effort in timing of an enemy's attack. Coupled with a powerful weapon, such as the Dabilahro, counters turn into {{OneHitKO}}s. The sequels required stricter timing and plenty of enemies' attacks are combo-driven.
** The SpinAttack from the first NES ''Ninja Gaiden'' was removed from the sequels. The [[InvincibilityPowerUp Invincible Fire Wheel]], an equippable (albeit expensive) Ninja Art was turned into a limited, single-use powerup for ''The Ancient Ship of Doom''.
*** The Art of the Fire Wheel is further {{nerf}}ed for the Xbox ''Ninja Gaiden'' compared to the NES days. It creates a flaming shield around Ryu, but it knocks away most enemies on contact which severely limits its usefulness (continuous damage is impossible and it knocks them out of your melee weapon's effective range). You are also far from invincible.
*** It has been un-nerfed in ''Razor's Edge'', as Momiji's Ninpo, although her ki gauge takes a long time to fill.
** Incendiary Kunai in ''II'' systematically dismembered enemies the first time and killed them with a second one. In ''Sigma 2'', those used by Ayane are quite effective in normal difficulty, but are about as useful as shuriken at higher difficulties. ''Sigma 2'' also removes the ability to charge arrows. Then again, since projectiles are rendered infinite in use, keeping them as powerful would've turned them into Game Breakers.
** ''Ninja Gaiden III'' indirectly {{nerf}}ed the [[SpinningPiledriver Izuna Drop]]: it's still an instant kill technique, but tougher human-sized {{mook}}s have to be weakened before you can lift them up, so it's not quite as overabused as in previous games.
* NewGamePlus: Used in ''Ninja Gaiden II''. ''Sigma 2'' and ''Razor's Edge'' subvert this a bit with Chapter Challenge Mode: once you beat any difficulty, you can redo the chapters individually with all your weapons and Ninpo upgraded (not unlike ''Franchise/DevilMayCry''), and can choose your character. So while it's not ''technically'' this trope, it functions as one, except your life bar's length depends on the chapter you play. The game is also slightly more difficult in this mode.
* NiceJobBreakingItHero: A minor example in ''II''/''Sigma 2'' (so minor that Ryu [[DidYouJustPunchOutCthulhu fixes it pretty fast]]) [[spoiler: While escaping Mt. Fuji with Sonia, a drop of Ryu's cursed Dragon Clan/Fiend blood revives the Archfiend Vazdah into its OneWingedAngel form]].
* NinjaPirateZombieRobot: Spriggans are a more literal example: giant, armored zombies with a chainsaw in one arm and a cannon in the other.
* NonDubbedGrunts: ''Dragon Sword'' has no English voice track, as Tecmo Toei felt no need to hire English voice actors, since the game only has grunts and a few words uttered through the whole adventure. Still it's quite impressive that all sounds and grunts alike are performed by the original Japanese voice actors, and actually recorded for production, not recycled tracks from the console versions.
* NoIAmBehindYou: The "Cicada's Surge" technique allows Ryu to teleport behind an attacking enemy in ''Razor's Edge''.
* NonStandardGameOver: You can actually shoot Sonia dead near the end of ''Ninja Gaiden II'', which will result in this.
* NoSidepathsNoExplorationNoFreedom: Averted in the first Xbox ''Ninja Gaiden'', as you can still explore a bit of Tairon or find a few secret paths, as well as stroll in previously visited areas; this is helped by the fact that 90% of the game takes place inside or near the city. Played straight with the sequels, being much more linear, especially ''III'', where there are no items to pick up, so any semblance of exploration has totally vanished. ''[[UpdatedRerelease Razor's Edge]]'' re-adds scarabs and secret areas, though.
* NumericalHard: The difference between Normal and Hard was barely noticeable in the Xbox ''Ninja Gaiden''. There were more, slightly tougher enemies, but that was pretty much it. Like so many other things, ''Black'' and ''Sigma'' corrected this by replacing basic {{mook}}s with new, tougher ones, and turning every boss into a FlunkyBoss.
* OmnicidalManiac: The Dark Dragon in ''Dragon Sword'', according to Nicchae, would've annihilated both humans AND fiends had Ryu not destroyed it soon after its birth.
* OncePerEpisode: In the modern series, the first three games has the Hayabusa Village attacked at the beginning − by Doku in the first and the Black Spider Clan in ''Dragon Sword'' and ''II''.
* OneHitKill: Master Ninja Mode's ungodly difficulty in ''Sigma 2'' relies on the fact that the player has very little room for mistake. Several enemy attacks like fire geysers, and any boss grapple or {{mook}} suicidal attack will kill you instantly regardless of your lifebar's length.
** In your arsenal, the Inazuma Drop for any non-boss humanoid enemy. The only caveat is that you have to actually pull it off.
* OneTimeDungeon: In the first Xbox ''Ninja Gaiden'', you can't go back to the Ninja Fortress from Chapter 1 nor enter the airship in Chapter 3 since it crashes.
* OneWingedAngel: Alma -> Awakened Alma, Doku -> Spirit Doku, and both forms of the Vigoorian Emperor in the Xbox ''Ninja Gaiden'' and the Archfiend in the sequel.
* OnlyAFleshWound: A game mechanic in ''II''/''Sigma 2'', where enemies act differently depending on how they've been dismembered. In some ways, they become more dangerous when they've lost a limb, and will liekly do a grab/suicide attack that's very hard to avoid and heavily damaging.
* OnlyIdiotsMayPass: Subverted in the modern games
* OurHomunculiAreDifferent: Homunculi in ''Ninja Gaiden III'' turn into Chimeras after you take them down. They are also the only enemies that ''[[MercyKill beg you to kill them]]'' while they attack you.
* PerfectPlayAI: The Doppelganger fiend in the first Xbox game would make you feel like you're fighting against a computer-controlled Ryu.
** The Regent of the Mask in ''Razor's Edge'' can also be quite infuriating, as he is mostly immune to Ultimate Techniques, dodges a lot and takes advantage of every little opening in your defense − and even his basic attacks deal quite a lot of damage. Dealing with him in higher difficulties requires a perfect knowledge of his pattern.
* PainfullySlowProjectile: Averted in ''Ninja Gaiden II'', where white ninja archers fire explosive arrows so fast you can't possibly dodge them in time; they're also unblockable and can hit you underwater. In Master Ninja Mode, you fight them right at the beginning, waiting for you across gaps or targeting you while running on water. [[FakeDifficulty Everyone's got their four-leaf clovers]]? Thankfully, they are fewer and a bit slower in ''Sigma 2''.
* PlayingWithFire: Art of the Inferno, Fire Wheel and Phoenix.
* PivotalBoss: [[WarmUpBoss The spider tank]] in ''Ninja Gaiden III'' is more or less this, although it can attack you even without facing you directly.
* PowerGlows: After you acquire the True Dragon Sword in the modern trilogy, it gains a purple aura. In ''Ninja Gaiden III'', Ryu's cursed arm glows red, indicating when you can unleash an Ultimate Technique.
* PrecisionGuidedBoomerang
** The Windmill Shuriken in the two Xbox games.
** You can throw the [[SinisterScythe Eclipse Scythe]] like a boomerang as a wall attack in ''Ninja Gaiden II''. ''Razor's Edge'' also adds this move as a hold-and-release attack.
* PressXToNotDie: One of the most frequent complaints regarding ''Ninja Gaiden III'' is the heavy use of scripted sequences -- of the "you can take a shower and have a tea before pressing the button" type.
* {{Prequel}}: The modern trilogy compared to the NES originals
* ProductPlacement: ''Ninja Gaiden II'' has some in the New York level, notably for Toshiba. Strangely, you don't see them in ''Sigma 2''.
* PunchClockVillain: Arguably the Special Forces and Vigoorian Military, though the journals found in ''Ninja Gaiden II'' show the Black Spider Ninjas to be something of this, too.
* RecurringBoss: Doku, Genshin, and Regent of the Mask.
** [[RedOniBlueOni The Tengu Brothers]] in ''Sigma 2'': you fight one alone in Chapter 5, who flees in the middle before you can finish it off; you fight them together at the end of the same chapter. At the beginning of Chapter 14, you fight the two but one of them escapes. You kill the other, and the one that escaped reappears at the end of the chapter, [[FlunkyBoss with a few other ninjas]]. Finally, the two reappear in Chapter 16. What's interesting is that you almost ''always'' have to fight them after going through several long and harsh fights, [[CheckPointStarvation with no possibility to save between the fights]], meaning you'll rarely confront them at full health.
* RealTimeWeaponChange: Deliberately averted in the modern series − asked about it at the time of ''Ninja Gaiden II'', Itagaki said that such a feature would change the game too much and that he prefers player to stick to one weapon during a fight. You can open a quick menu with the d-pad to change weapons, but it pauses the game.
* RecurringRiff: "A Hero Unmasked" in the soundtrack of ''Ninja Gaiden III''
* RefugeInAudacity: The boob-jiggling feature in ''Sigma 2''; you can even do it during ''cutscenes''.
* RespawningEnemies: Averted beginning with ''Ninja Gaiden II'': once you've wiped out a wave of enemies, it's for good.
* {{Revival}}: NES trilogy -> Modern trilogy. Also counts as a VideoGame3DLeap.
* RockBeatsLaser: [[VideoGame/BaldursGate Vigoorian forces, meet Dragon Sword! Dragon Sword, meet Vigoorian forces]]! Subverted against tanks and a helicopter, which Ryu needs to use specially-tipped arrows to destroy.
** Note a bow is simply outdated since {{mook}}s have access to firearms at that point. [[FridgeLogic What sensible military would use resources to make armor-piercing/explosive arrows for a weapon as outdated as a bow, especially since enemies gain increasingly large caliber guns as the game progresses]]?
* RPGElements: The Mission Mode and online modes for ''Ninja Gaiden III'' has you start as a low-ranking {{ninja}}. Completing trials will level up your character, improving combos and equipment. This is quite surprising, as the story mode in the same game removed everything that remotely looked like an upgrade system.
** ''Razor's Edge'' rectifies story mode, but with a different mechanic: players will use Karma points to upgrade weapons, Ninpo, increase the life bar and gain new techniques.
* RuleOfCool: The modern trilogy thrives on this.
* SceneryPorn: Some of the levels in ''Ninja Gaiden II'' are ''gorgeous''. Special mention goes to the chapter taking place atop the Tokyo skyscrapers. The game also has one of the more beautiful game portrayals of central Moscow (albeit the city is never named), going through Red Square, the GUM, the Underground, some nearby churches and buildings, before ending in Spaskaya Tower. [[SymbologyResearchFailure St. Basil's Cathedral]], unfortunately, is absent.
* ScoreMultiplier: In ''Razor's Edge'', after killing a few enemies, you enter "bloody rage mode", where your weapon/right arm starts to glow red: by holding triangle you can trigger an instant Ultimate Technique, but as long as you don't, a Karma multiplier will appear and increase each time you kill an enemy. Note than in the original ''Ninja Gaiden 3'', the "red arm" was just the new way to activate ultimate techniques and didn't have any other function.
* SelfImposedChallenge: Karma runs; other popular ones include finishing the game with no upgrades or without using [[ElementalPowers Ninpo]] and [[ChargeAttack Ultimate Techniques]].
* SequelDifficultyDrop: A good part of the bashing ''Ninja Gaiden III'' received is [[ItsEasySoItSucks due to this]]. The thing is, Hard Mode is still just as brutal as ever, so the jump between Normal and Hard is pretty steep.
* SequelDifficultySpike: Or rather "re-release difficulty spike" − the original Xbox ''Ninja Gaiden'' was hard but nothing pain-inducing. ''Black'' (and by extension ''Sigma'') cranked it up a couple notches by introducing new vicious enemies, giving pre-existing ones better AI (and a grappling maneveur for Black Spider Ninjas), throwing out the window what little MookChivalry they could have, significantly {{nerf}}ing overly efficient moves like the Counter or Flying Swallow and adding the utterly sadistic Master Ninja Mode.
** ''Ninja Gaiden II'' is also infamous for being this, [[FakeDifficulty but not always in a good way]].
* SequelEscalation: ''Ninja Gaiden Black''/''Sigma'' are NintendoHard with moderate gore, playthroughs are done at a relatively slow pace, you never fight more than three or four enemies at once and the strongest techniques are restricted in use. ''II'' takes the gore to [[LudicrousGibs ridiculous levels]], is considerably faster, requires offensive strategies and you frequently fight insane number of {{mook}}s. Combos, weapons and Ultimate Techniques are cranked up to the point they would've been absolute {{Game Breaker}}s in the first game. ''Sigma 2'' toned down the gore and number of enemies, though increased AI and boss/{{mook}} resilience, ''Sigma Plus 2'' included all that in addition to restoring the gore.
* SerialEscalation : ''Sigma 2'' features a co-op based Mission Mode with five levels - Acolyte, Warrior, Mentor, Master Ninja and Ultimate Ninja. The latter has missions that make even the most experienced players have a HeroicBSOD the first time, like fighting the Four Greater Fiends ''simultaneously''. You won't be able to do anything in those missions without an experienced human partner.
* SliceAndDiceSwordsmanship: Both used and averted depending on which technique Ryu pulls off in the modern games.
* SmashMook: Ogres from ''Ninja Gaiden Black''
* SmokeOut: Smoke bombs are used by both Ryu and enemy ninjas in the modern trilogy.
* SpamAttack: Most Ultimate Techniques
* SpinAttack: Ryu's movelist with the Dragon's Claw/Tiger's Fang consists of some hard cuts and a lot of spinning. Certain weapons also have access to a 360 degree input that usually turns out to be a spin attack. In ''Razor's Edge'', the shuriken gets its own spin attack.
** Most of the "hold-and-release" strong attacks in ''III'' involve spinning horizontally or vertically.
* SpyCatsuit: The UsefulNotes/XBox ''Ninja Gaiden'' gave one sleeve-less ninja version to Ryu (coupled with a ScarfOfAsskicking and a CoolMask to boot), and it's been his default costume both in his own series and the ''Videogame/DeadOrAlive'' series ever since.
* SquishyWizard: In the modern games, mages are annoying and potentially very damaging long-distance attacks, but are the weakest human enemies in terms of health. Of course, they're only squishy compared to other ninja {{mook}}s, but still.
** Completely averted in ''Ninja Gaiden III'': Alchemists are among the toughest enemies in the game, especially the white-clad variant.
* StealthPun: This one's a bit of a stretch, but "Florentine" is both an Italian identity (via its city) and a term used for DualWielding. In ''Sigma 2'', Ryu receives dual katanas in the Venice-based chapter (Venice being a city in Italy).
* StoryDifficultySetting: "Hero Mode" in ''3'' and in both ''Sigma Plus'' games, where blocking and evading becomes automatic if your health is low, which means the player basically cannot die. WordOfGod was that this mode was made for those who just wanted to enjoy the story. The UpdatedRerelease of ''3'' ''Razor's Edge'' keeps Hero Mode but also has a NewGamePlus-ish mode that, conversely, removes the cutscenes and QuickTimeEvents to keep only the gameplay.
* {{Stripperiffic}}
** Rachel's outfit is barely there.
** Sonia's outfit in ''Ninja Gaiden II'' is just as much, if not more so, to the extent where the diaphanous gown-and-lingerie ensemble she ends up near the end of the game is probably ''less'' revealing.
** Momiji's "Ninja" outfits (her black and red-and-white ones in particular) in ''Ninja Gaiden II'' and ''Razor's Edge'', which show a bit of skin on rather interesting parts of her body (namely around her [[SideBoob chest]], [[SexyBacklessOutfit back]], and thighs).
* ShutUpHannibal: In the aftermath of a boss fight in ''3 (Razor's Edge)'', said boss would go on a rant of how the humans will be cleansed. As Ryu, your job is to slowly drag yourself there and [[TalkToTheFist make him talk with your sword instead. Literally.]] And it is glorious.
* SwipeYourBladeOff: Will often be done by Ryu with all of his weapons in ''Ninja Gaiden II''. Great: ''more'' blood to clean up.
* SwordBeam: The double katanas' Ultimate Technique in ''Razor's Edge'' has Ryu spin rapidly before launching three of these.
* SwordOfPlotAdvancement: Getting the Eye of the Dragon to upgrade the Dragon Sword to the True Dragon Sword in every game of the modern trilogy.
* TakingYouWithMe: A good deal of any crippled, dismembered enemies in ''Ninja Gaiden II''. As well, the Armadillo bosses explode upon death, killing Ryu instantly if he doesn't block.
* TeleportSpam: Some of Ryu's Ultimate Techniques gain this.
* ThereIsNoKillLikeOverkill: The combo system allows characters to keep mangling decapitated enemies.
* ThrivingGhostTown: Tairon, capital of the Vigoor Empire, doesn't seem to have anyone other than a lone shopkeeper and a bunch of military personnel. Subverted when there are people in the nightclub, but they all run screaming when a giant dinosaur-fiend shows up. That, and the Vigoorian military imposes a curfew more or less as soon as Ryu shows up.
* TeasedWithAwesome: The Blade of the Archfiend at the end of ''Ninja Gaiden II''. Since you get it at a point when only bosses and large enemies remain, you can only use the Underworld Drop (the most powerful combo in the game) during NewGamePlus.
* TemporaryOnlineContent: The [[DownloadableContent Hurricane Packs]] for the original Xbox game, following the discontinuation of the original Xbox Live service. While ''Ninja Gaiden Black'' carries over most of the content from the Hurricane Packs (extra game modes and costumes), it also removes the famed Intercept move, which was deemed [[GameBreaker too powerful]] by the developers.
* TurnsRed: The Armadillo bosses in ''Ninja Gaiden II'' turn red and glow when their health is low, becoming somewhat more dangerous. When finally killed, [[MadeOfExplodium they explode]]. Ogres and Berserkers in ''Black'' and gorilla Chimeras in ''III''.
* UnexpectedGameplayChange: [[BiggerBad The Emperor]] in the Xbox ''Ninja Gaiden'' is fought on a floating platform that you must move back and forth (default) or up and down (by holding the guard button) to avoid its BeamSpam. It's painfully unintuitive and tedious.
* UnexplainedRecovery: Ryu's adventures in New York end with an animated Art/StatueOfLiberty using up its last moments of movement and first moments of freedom extending its hand to helt him escape before sinking into the sea. Rachel's chapter in ''Sigma 2'' sees said statue right back where it should be as the sun rises.
* UpToEleven: The Xbox ''Ninja Gaiden'' was already a violent game, but ''II'' makes the first game look pretty tame. Fights against large groups of enemies are essentially guaranteed to turn into utter bloodbaths as Ryu dismembers enemies and, with the right weapons, can cut enemies in two.
** Forget clean cuts: certain weapons can make body parts explode on impact. Extended use of those weapons can leave gibs on the floor and walls everywhere you go. In fact, the blood and body parts remain in the background for as long as you are playing the level with any enemy that doesn't dissolve upon being defeated. Ah, the wonders of technology.
* VeryDefinitelyFinalDungeon: The Imperial Palace in the Xbox game. It's an enormous tower hanging [[GravityScrew upside down]] and covered in giant skulls. It's so very definitely final, that even the item chests are evil and spiky.
* WakeUpCallBoss: Murai, the first boss of Xbox ''Ninja Gaiden'', is a classic example of this. Still, almost every subsequent boss serves as this, popping up if only to hammer you for thinking the rest of the game would be smooth sailing (Alma's first encounter, for example).
** Regent of the Mask in ''III''
* WallCrawl: The Kunai Climb allows Ryu to climb walls made of wood, brick, stone, ice or even metal. Those kunais mst be pretty damn sharp.
* WeDontSuckAnymore: Team Ninja admitted that they tried too hard to catch a western audience with ''Ninja Gaiden 3'' and ended up neglecting old fans of the series. As a result, the massive changes made to the gameplay for ''[[UpdatedRerelease Razor's Edge]]'' are a mix of backpedalling to ''Ninja Gaiden II''[='s=] popular elements (dismemberments, Ninpos, fast weapons) and overhauling of ''3'''s new mechanics (Ki system, Grip of Murder, Steel-on-bones), peppered with a few new techniques and features, and a difficulty cranked up a couple notches. [[MercyMode They kept Hero Mode, though]].
* WhatMeasureIsAMook: For a series that took much joy in slicing and dicing opposing mooks, ''Ninja Gaiden III'' [[http://www.youtube.com/watch?v=AYjO2Hs1zRU&feature=player_embedded attempted to turn this into a plot point]]. Also, when you perform the fire-dragon Ninpo the first time, {{mook}}s around drop their weapons and stop fighting; you have the choice to coldly finish them or let them live (it happens in Normal mode only).
* WorldOfBuxom: Only female children are exempt from it.
* WrestlerInAllOfUs: Guillotine Throw and Izuna Drop. Ayane in ''Sigma 2'' has a scissors lock in place of the Guillotine Throw.
* YouShallNotPass: Said word-for-word by Shadow Ninja Rasetsu in the first boss fight of ''Ninja Gaiden II''.
* ZombieApocalypse: ''Yaiba: Ninja Gaiden Z'' is set to have some zombie themes.

'''[[LampshadeHanging ''HARD TO BEAT!!'']]'''