[[quoteright:270:http://static.tvtropes.org/pmwiki/pub/images/270px-mmx4promo_7840.jpg]]

''Mega Man X4'' is the fourth entry in the ''VideoGame/MegaManX'' series, released on the UsefulNotes/PlayStation and UsefulNotes/SegaSaturn on July 1997 in Japan, August 1997 in North America, and October 1997 in Europe. It was also the first ''Mega Man X'' game not to be released on the SuperNintendoEntertainmentSystem.

[[ExtyYearsFromNow In the year 21XX]], two large reploid armies to combat the outbreak of Mavericks exist, the Maverick Hunters including X and Zero, and the Repliforce. The two great organizations have worked together several times to counter Maverick activity, and it was during this time that Zero gets to know the Colonel and his sister Iris of the Repliforce. With the Maverick Hunters, X has also befriended a new ally, a clumsy rookie named Double.

But one day, the aerial city of Sky Lagoon is targeted by Mavericks, causing it to crash to the earth causing thousands of causalities. As Repliforce was in the area during the attack, they are asked to disarm themselves and come in for questioning; however, the Colonel refuses due to his pride. To make matters worse, the Repliforce leader, General, launches a coup d'état to start a nation only for Reploids to exist, which soon causes him and the entirety of Repliforce to be labeled as Mavericks by the government, forcing the Maverick Hunters to turn against their once allies.

Mavericks:
* Web Spider of Repliforce, gives [[FloatingPlatforms Lightning Web]] to X, and [[ShockAndAwe Raijingeki]] to Zero; is weak to Twin Slasher/Shippuuga
* Magma Dragoon of the 14th Special Unit, gives [[PlayingWithFire Rising Fire]] to X, and [[FlamingSword Ryuenjin]] to Zero; is weak to Double Cyclone/Raijingeki
* Storm Owl of Repliforce, gives [[RazorWind Double Cyclone]] to X, and Tenkuuha to Zero; is weak to Aiming Laser/Rakuhouha
* Split Mushroom of Sigma's forces, gives [[SelfDuplication Soul Body]] to X, and [[SpinAttack Kuuenzan]] (as well as [[DoubleJump Kuuenbu]]) to Zero; is weak to Lightning Web/Raijingeki
* Frost Walrus of Repliforce, gives [[ElementalBarrier Frost Tower]] to X, and [[AnIcePerson Hyouretsuzan]] to Zero; is weak to Rising Fire/Ryuenjin
* Slash Beast of Repliforce, gives [[SpreadShot Twin Slasher]] to X, and [[DeadlyLunge Shippuuga]] to Zero; is weak to Ground Hunter/Raijingeki
* Jet Stingray of Repliforce, gives [[MookMaker Ground Hunter]] to X, and [[VideoGameDashing Hienkyaku]] to Zero; is weak to Frost Tower/Hyouretsuzan
* Cyber Peacock of Sigma's forces, gives [[PlayerGuidedMissile Aiming]] [[FrickinLaserBeams Laser]] to X, and [[SmartBomb Rakuhouha]] to Zero; is weak to Soul Body/Ryuenjin

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!!Tropes:
* AllThereInTheManual: Did you know that Colonel and Iris used to be one reploid? And that said reploid was supposed to be a clone of X? It didn't work, however, and needed to be split to allow any sort of functionality, with Colonel gaining X's fighting spirit and sense of justice, whereas Iris retained X's compassion and pacifism.
* AscendedExtra: Zero was technically PromotedToPlayable in ''[[VideoGame/MegaManX3 Mega Man X3]]'', but this game allows him to be chosen as the main playable character from the start, and gives a lot of CharacterDevelopment. Unlike X, he gains 3 cutscenes involving him whereas alongside X's ending where he worries about being a Maverick and Double's betrayal.
* BackFromTheDead: Despite seemingly being destroyed for good at the end of X3 by Dr. Doppler's antivirus, Sigma somehow managed to survive it and create an antidote. His appearance in a Grim Reaper garb is quite appropriate for his comeback.
* BilingualBonus: All of Zero's sword techniques retain their original Japanese names; for instance, Raijingeki translates to ''"Thunder God Attack"'' and Ryuenjin means ''"Dragon Flame Blade"''.
* BittersweetEnding: [[spoiler: While X's ending is only somewhat bittersweet, Zero's ending really qualifies for this. Sigma is once again defeated and the Final Weapon is destroyed along with him, but the Repliforce fiasco has taken untold lives, not just the thousands killed in the Sky Lagoon crash and the subsequent war, but including all of the newly introduced major characters such as Iris, Colonel and General (the former two being killed by Zero, the latter performing a HeroicSacrifice to destroy Final Weapon). Also, Zero tragically discovers his terrible history of being built by Dr. Wily, starting as a Maverick and unwittingly being the source of the Sigma virus. Even after he saves the day, he even believes he has the possibility of going Maverick again. Whereas [[VideoGame/MegaManX1 the first]] [[VideoGame/MegaManX2 two games]] ended on a triumphant note and [[VideoGame/MegaManX3 the third game]] on a mildly bittersweet note, this game really ended in a much more melancholy way.]]
** [[spoiler: It also retroactively turns X3's ending into a DownerEnding; we find out in this game that despite his efforts, Dr. Doppler's antivirus is useless against the Sigma Virus in the long run, the latter finding a way to overcome it, and that Sigma didn't even ''need'' to infect others to incite a war, but instead pull strings and turn the Reploids against each other. Doppler's efforts and HeroicSacrifice in X3 was all for nothing.]]
* BloodKnight: Magma Dragoon sabotages [[ColonyDrop Sky Lagoon]] and kills thousands just to force X or Zero to have to fight him in a final duel to the death.
* BossSubtitles: After choosing which stage to enter, it begins with a single paragraph explaining what the Maverick did, along with the Maverick's name and sprite. Also, a TitleScream of the boss's name.
* BossWarningSiren: This game introduced them to the series.
* TheCameo: [[VideoGame/MegaManX1 Chill Penguin]] and [[VideoGame/MegaManX3 Blizzard Buffalo]] can be seen frozen in the background of Frost Walrus's stage.
* CharacterDevelopment: Zero gets a lot of development in this game, something that would continue in the next games.
* ColonyDrop: Sky Lagoon during the intro stage.
* DarkerAndEdgier: For the first time, the Maverick label is used on a group not infected with the Sigma Virus[[note]]Note that the Mavericks in X1-X2 are {{retcon}}ned to have been infected[[/note]] (though Repliforce may or may not have brought it on themselves by being so stubborn) and Zero's ties to Dr. Wily are revealed, not to mention [[spoiler:Iris' death, which would continue to haunt Zero after the game.]]
* DesignatedLoveInterest: Iris to Zero; they got together sometime between ''VideoGame/MegaManX3'' and this game, and don't share much romantic screentime in the game proper [[spoiler:before Iris's death]].
* DiedInYourArmsTonight: [[spoiler:Iris dies in Zero's arms]].
* DoubleAgent: [[spoiler:[[MeaningfulName Double.]]]]
* DraconicHumanoid: Magma Dragoon.
* DreamIntro: Zero's storyline starts with him having a nightmare of a mysterious figure telling him to destroy the world.
* EasyLevelsHardBosses: When playing as Zero. His agility makes him great in the main stages, but since he gains new ''moves'' rather than new weapons, he can't always exploit the bosses' weaknesses. He has no animation-interrupting move against Slash Beast and Magma Dragoon, for instance.
* EvilLaugh: [[spoiler: Sigma]] in his [[VillainOpeningScene introductory scene]] with the General after the General dismisses him, but not before [[spoiler: Sigma]] assures that the General would soon change his mind about the Maverick Hunters. And he laughs again when he realizes that the General has taken action against the Maverick Hunters in his speech to Repliforce.
** Also, [[spoiler: [[TheMole Double]]]] laughs after he reveals his true form and slaughters some Reploids at the Maverick Hunter HQ, vowing to target X.
* {{Expy}}: Magma Dragoon is pretty much Akuma as a dragon reploid.
* FaceHeelTurn: Former Maverick Hunter, Magma Dragoon.
** Once accused of turning Maverick, Repliforce starts a coup d'état to create a separate nation only for Reploids.
** [[spoiler:Iris turns on Zero after Zero kills her brother]].
* FireIceLightning: Magma Dragoon, Frost Walrus, and Web Spider respectively.
* FlyingSeafoodSpecial: Jet Stingray, as well as the Kill Fisher enemies in Web Spider's stage.
* FlunkyBoss: Web Spider and Jet Stingray can shoot out spider and stingray drones respectively. Meanwhile, Split Mushroom can deploy multicolored clones of himself, as well as creating a real body double.
* GetOut: A calmer example; in the opening cutscene, Sigma attempts to sway the opinion of General into turning against the Maverick Hunters, under the pretense that they're far too eager to please humans and hunt down reploids. General coldly turns down his offer and orders him to leave his presence. Sigma is unfazed though, and accurately concludes that he'll change his mind later before he departs.
* GiantSpider: Web Spider of the Repliforce.
* TheGrimReaper: [[spoiler:Sigma]] disguises himself in a Grim Reaper motif, complete with black robes, [[TheFaceless shadowed face]], and a [[SinisterScythe Sinister]] [[LaserBlade Laser Scythe]].
* HardLevelsEasyBosses: When playing as X. As usual, you can rip through bosses like nothing if you know their weaknesses, many of which [[AIBreaker interrupt the boss's attacks,]] and even weaken them beyond damage dealt.
* HeroicBSOD: [[spoiler:Iris' death]] triggers one for Zero, one that lasts all the way until ''VideoGame/MegaManZero 4''
* HeroicSacrifice: [[spoiler:General ends up sacrificing himself to stop the KillSat Sigma had commandeered to KillAllHumans]].
* [[HijackedByGanon Hijacked By Sigma]]: The games cutscenes make it clear right off the bat that Sigma is alive and is going to be the real villain of the game, but X and Zero don't find that out until they fight him at Final Weapon. Split Mushroom [[LampshadeHanging lampshades]] this if you're playing as X.
* HonorBeforeReason: After the Sky Lagoon incident, Colonel refuses to disarm his troops to come in for questioning out of pride, which, [[AllThereInTheManual combined with their lacklustre performance on the field]], which makes Repliforce as a whole look suspicious.
** Several Repliforce generals, including Storm Owl and Jet Stingray, start attacking innocent civilians in order to drive attention to themselves and away from Repliforce as they prepared to launch into space. This, of course, simply justifies the mandate that Repliforce has turned Maverick and must be destroyed.
* HumongousMecha: Eregion is as tall as the screen. Frost Walrus is possibly the largest "eight stage bosses" character in all of Mega Man (Rainy Turtloid of ''X6'' comes second), as he stands at 3/4 of the screen height, even larger than [[VideoGame/MegaMan8 Frost Man]]. General is even taller.
* InstantAwesomeJustAddDragons: [[WarmupBoss Eregion]] and Magma Dragoon.
* KillEmAll: [[spoiler:Every character in ''X4'' except X and Zero are dead by the end of the game]].
* KillSat: The Repliforce space station[[spoiler:, Sigma plans on using the space laser to destroy all life back on earth]].
* KingOfBeasts: Slash Beast is a lion reploid, and he certainly acts the part.
* LandSeaSky: Slash Beast, Jet Stingray and Storm Owl respectively are the army, navy and air force generals of Repliforce.
* LaserBlade: Zero now exclusively use the Z-Saber as part of the SuperheroSpeciation. Colonel also uses one.
* LightningBruiser: Slash Beast is quite strong and hardy, and fast enough to outrun a moving train. Magma Dragoon as well.
* TheMole: [[spoiler:Double]].
* MonstrosityEqualsWeakness: Eregion is the second-largest boss in the game and is [[WarmupBoss also the most pathetic]].
* MushroomMan: Split Mushroom.
* NaiveNewcomer: Double is a new rookie Maverick Hunter who likes to tag along with X[[spoiler:, [[ObfuscatingStupidity or so it]] [[TheMole would seem]]]].
* NearVillainVictory: [[spoiler: Sigma has turned the Repliforce against humanity and caused countless loss of life on both sides, and his string pulling results in Colonel and Iris getting killed by Zero and nearly destroying General, and Final Weapon is mere seconds away from accomplishing its goal by the time X or Zero mop the floor with him. If General hadn't been functional enough to perform a HeroicSacrifice by [[TakingYouWithMe destroying the Final Weapon along with himself]], Sigma's plan would have actually succeeded.]]
* NiceHat: Many Repliforce officers wear one, like Colonel, General, Web Spider, Jet Stingray, and Storm Owl.
* NotHelpingYourCase: Even when it turns out that Repliforce didn't do anything to the Sky Lagoon at all, they don't do much to cover themselves either - see HonorBeforeReason for why.
* ObfuscatingStupidity: [[spoiler:Double]].
* OminousOwl: Storm Owl.
* [[PeacockGirl Peacock Guy]]: Cyber Peacock. Even though he's not female, he acts a little campy.
* PreAssKickingOneLiner: Most bosses do this.
* [[PromotedToPlayable Promoted To Fully Playable]]: Zero.
* RememberTheNewGuy: Repliforce, we're made to understand they've been around for awhile and have worked with the Maverick Hunters on several occassions. Based on the memo in the accompanying booklet, they had been established after the third game.
* SayMyName:
--> '''Zero''': [[spoiler: Iris?! Iris! Iris! Iris... [[TheScream AAAAAAAHHHHHHH!!!!!]]]]
* SchrodingersPlayerCharacter: There are 2 storylines, one for X and one for Zero. When you choose one, the other won't appear, except in one case: In X's ending, Zero contacts him.
* ShoutOut: Magma Dragoon is a big one to Akuma of the ''Franchise/StreetFighter'' franchise, he even uses the {{Shoryuken}} and the [[KamehameHadoken Hadoken]] by name.
** When he does the Twin Slasher, Slash Beast does a somersault akin to Guile's Flash Kick.
* {{Shotoclone}}: Magma Dragoon
* SinisterScythe: [[spoiler:[[BigBad Sigma]]]] uses a [[LaserBlade Laser Scythe]].
* SplitAtBirth: Colonel and Iris, as together they used to be a single reploid built with the intention of being a clone of X, but were split into two beings, each retaining parts of X's personality. This is even evident in their relationship to Zero, Colonel is TheRival to Zero, someone with X's fighting ability and honor for Zero to compete against, whereas Iris acts as a [[TrueCompanions True Companion]] to Zero, someone with X's compassion for Zero to feel a deep connection with.
* TeleportSpam: Cyber Peacock and Colonel.
* TrailersAlwaysSpoil: [[https://www.youtube.com/watch?v=hyFeS-9zOiA The Japanese commercial]] for this game shows the infamous scene where [[spoiler: Zero yells "WHAT AM I FIGHTING FOR?!" while cradling Iris's corpse.]]
* UtilityWeapon
** [[ShockAndAwe Lighting Web]] can be used to make an [[ImprovisedPlatform improvised wall]] for X to WallJump off of.
** [[PlayingWithFire Rising Fire and Ryuenjin]] can burn wooden logs or ice blocks.
** A [[ChargedAttack fully charged]] Twin Slasher can be used to break away heavy stone blocks.
* WarmupBoss: Eregion, the bipedal dragon Mechaniloid of the Sky Lagoon stage.
* WhenAllYouHaveIsAHammer: Zero only has his [[LaserBlade Z-Saber]], so most of his upgrades give him more powerful or versatile sword techniques.
* WilyWalrus: Frost Walrus is a gigantic walrus with ice powers who looks down on the small and weak and acts like a roughneck.
* XanatosGambit: [[spoiler: Sigma]] pulls one here; If either the Maverick Hunters or Repliforce wins, he can aim the Final Weapon on the Earth. The only reason he plans fails was because [[spoiler: General survive his fight with X and Zero and stops the weapon himself.]]
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