''Mega Man X'' is the first entry in the ''VideoGame/MegaManX'' series, released on the SuperNintendo on December 17 1993 in Japan, January 1994 in North America, and May 1994 in Europe.
Set in 21XX, Dr. Cain discovers a robot sealed away in a capsule left by the late Dr. Light, that is capable of highly advanced AI and even free will. Dr. Cain studied the robot, known as "X", and attempted to duplicate his functions, these robots later became known as "Reploids".
However, under free will, some of the Reploids went rogue, and thus were branded as "Mavericks". To counter the threat, the Maverick Hunters were formed, with Sigma as the leader. However, soon afterwards, Sigma himself goes Maverick, taking the Hunters with him. X, not wanting to the fighting to continue, heads out to confront the Mavericks, joining Zero, the new leader of the Maverick Hunters.
* Chill Penguin of the 13th Polar Region Unit, gives the [[AnIcePerson Shotgun Ice]]
* Spark Mandrill of the 17th Elite Unit, gives the [[ShockAndAwe Electric Spark]]
* Armored Armadillo of the 8th Armored Division, gives the [[ThrowingYourShieldAlwaysWorks Rolling Shield]]
* Launch Octopus of the 6th Marine Unit, gives the [[HomingProjectile Homing Torpedo]]
* Boomerang Kuwanger of the 17th Elite Unit, gives the [[BattleBoomerang Boomerang Cutter]]
* Sting Chameleon of the 9th Special Forces, gives the [[SpreadShot Chameleon Sting]]
* Storm Eagle of the 7th Air Cavalry Unit, gives the [[TornadoMove Storm Tornado]]
* Flame Mammoth of the 4th Overland Unit, gives the [[PlayingWithFire Fire Wave]]
Was later [[VideoGameRemake remade]] as ''VideoGame/MegaManMaverickHunterX'' for the PSP.
* AttackOfTheFiftyFootWhatever: Sigma's OneWingedAngel form.
* AwesomeButImpractical: The Hadouken. It can kill anything in a single shot, including bosses. Unfortunately, it can only be used if X has full health, it can only be fired while on the ground, and it's somewhat difficult to land it, particularly against fast-moving targets.
* BadBoss: It is heavily implied that Flame Mammoth spends most of his time in his unit mocking those inferior to him in terms of strength. As an added bit of laser-guided karma, he's also the only one of the former Maverick Hunters that defected to Sigma's side to not have any of his unit go with him, although given the setting where he is fought, he probably didn't need them anyways.
* BackgroundBoss: Rangda Bangda and Sigma's OneWingedAngel form.
* BigDamnHeroes: Zero, who saves X just before he gets destroyed by Vile in the opening level.
* BlackoutBasement: Spark Mandrill's stage, especially if entered after beating Storm Eagle.
* BossRush: This game is the only one to intersperse boss fights throughout Sigma's Fortress, much like the first ''[[VideoGame/MegaMan1 Mega Man]]'' game.
** Retroactively doubles as a MythologyGag, since every game after it does the teleporter-style boss rush.
* BribingYourWayToVictory: In the iPhone version of the game, Sub-Tanks and Armor Pieces can be purchased. Many people have not approved of this change.
* ButThouMust: There's no way to not encounter Dr. Light's capsule in Chill Penguin's level or to refuse [[spoiler: Zero's Arm Part]].
** Probably because the game is exorbitantly harder without it. A SelfImposedChallenge is to start the game using a passwords that has Chill Penguin defeated, but without upgrades.
* ChargedAttack: By default, X can charge his Buster up to 3 levels, however once he obtains the Arm Parts, he can not only charge his Buster up to 4 levels, he can now charge all of his weapons.
* ContractualBossImmunity: Surprisingly averted with the Hadouken. The bosses go down in one hit to it just like everything else. The only exceptions to it are Vile's Ride Armor and Sigma's final form on the SNES version.
* DiscOneNuke: It's tricky, but far from impossible to beat Storm Eagle first (without the ability to dash against his wind) so long as you know where and when to start running. The reward, Storm Tornado, rips through stages like nothing.
* GuideDangIt: Unlocking the Hadouken requires you to, among other things, complete one otherwise-unremarkable stage seven times in a row.
* [[spoiler:HeroicSacrifice: Zero.]]
* HollywoodChameleons: Sting Chameleon.
* HopelessBossFight: Twice with Vile.
* ImprovisedPlatform: Charging up Shotgun Ice will allow X to fire out a sled that he can ride on.
* InfinityPlusOneSword: The Hadouken.
* InstructiveLevelDesign: The game's level design is such that it teaches you different techniques by throwing you into situations that require them. By the end of the first level, the player will have had to use all of X's platforming abilities at least once. The only exception is charging the X-buster, but Zero does that during his BigDamnHeroes moment to encourage you to try and follow his example.
** TeachingThroughAccident: How wall jumping is learned.
* InvincibilityPowerUp: The charged Chameleon Sting lets X pass through enemies.
* LethalLavaLand: Flame Mammoth's stage is this; at least before you defeat Chill Penguin.
* MinecartMadness: Armored Armadillo's stage. The minecarts themselves travel ''very'' fast, mow down nearby Mooks in an instant, and are in fact required to cross the large chasm connecting the end of the mine to the entrance of the BossRoom.
* MultipurposeTongue: Sting Chameleon is all about this trope. He uses his tongue as his primary attack, and can hang from the ceiling to rain damaging spikes down from the ceiling.
* OneHitKill: X gets one in the Hadouken.
* RemovableShell: Armored Armadillo; he'll lose his shielding if he's hit with the Spark Shot.
* SelfImposedChallenge: Several, and can be combined for even more challenge
** Low% (not taking any upgrades except the Boots, which cannot be skipped except via password, and Zero's cannon)
** No damage
** Buster only
** Reverse boss order (defeating the bosses in the opposite order of their weakness)
* SequenceBreak: It turns out there are a few quirks in the physics engine that allows for speedrunning shenanigans, to wit:
** The heart tank in Sting Cameleon's stage can be reached even before it's flooded by using Shotgun Ice's sled, or extremely precise dash-jumping.
** Ditto the heart tank in Boomer Kuwanger's stage.
** The cutscene confrontation between Zero and Vile in Sigma's fortress can be skipped, as well as part of the sequence afterwards.
** The Shotgun Ice sled can also be used to skip the re-fight with Armored Armadillo by taking advantage of screen scroll.
* SequelHook: After the end credits; Sigma shows up on a screen and taunts X, saying that his spirit still lives on, which turned out to be a hint about Sigma's true nature as TheVirus.
* SmashingSurvival: Used to escape the Gulpfer fish if you get SwallowedWhole.
* TraumaticSuperpowerAwakening: After Zero [[spoiler: sacrifices himself]], X suddenly breaks free of his electric bonds and fully restores him energy before the showdown with Vile. Even Vile has no idea how this is possible. This hidden power isn't mentioned again, and was removed in ''Maverick Hunter X''.
* TurnsRed: This was limited to two of the Sigma fortress bosses simply moving faster.
* VideoGameRemake: ''VideoGame/MegaManMaverickHunterX'', which serves as a ContinuityReboot.
** OrphanedSeries: Was to be a whole series of reboots, but got sacked.