''Raiden'' is a popular and influential series of vertical ShootEmUp created by Japanese developer Seibu Kaihatsu, and later handled by MOSS. It is quite notable for popularizing (though not necessarily [[OlderThanTheyThink creating]]) many concepts and conventions still used by vertical shmups today. Spawned the ''VideoGame/RaidenFighters'' series.

The plot of the series is completely nonexistent and inconsequential, much like most shoot'em ups. The gist is that a race of aliens called the [[FanNickname "Cranassian Empire"]] is invading Earth, and it's up to the Raiden supersonic jet to stop them.

The series is composed of the following games:

* ''Raiden'' (later ported to the SNES and Genesis as ''Raiden Trad'')
* ''Raiden II''
** ''The Raiden Project'' (A CompilationRerelease of the first two games for the Playstation)
** ''Raiden DX'' (an extension of Raiden II with a more elaborate scoring system and several different modes)
* ''Raiden III''
* ''Raiden IV''
** ''Raiden IV Overkill'' (an extension of IV for [[PlaystationNetwork PSN]] with a new game mode)

Not to be confused with the thunder god of ''MortalKombat'', or the Franchise/MetalGear character of the same name, or the big wrestler from FatalFury...
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!!The series exhibits the following tropes:
* AirborneAircraftCarrier: All of the games begin by launching from one of these, and end by landing on it.
* BigBad: The giant, ominous red diamond that debuts in ''Raiden II'' and seems to be the enemy leader, [[ExcusePlot at least from]] [[WildMassGuessing what can be observed]]. It spends the bulk of the game harrying you by [[VillainExitStageLeft flying out of the wreckage of every boss fight]], confronts you as the FinalBoss, and comes back for more as the end boss of ''III'' and ''IV''.
* BookEnds: ''Raiden IV'''s TrueFinalBoss [[spoiler:kicks off with a [[CrowningMusicOfAwesome glorious reprise]] of "Repeated Tragedy", the stage 1 theme of ''Raiden II'', and ends with the boss theme of the original game, signalling the whole series coming full circle.]]
* BoringButPractical: The red SpreadShot, mostly because if (''if'') you can nose up close enough to an enemy to make all of the spray hit it, it will suffer more damage more quickly than even with the full-power blue laser. It is ''not'' uncommon to get a mid-sized enemy destroyed this way before it can even start shooting. At further range, the spread is wide enough that anything in front of you will continuously be pelted with damage, the only drawback being that you have to [[ButtonMashing mash]] on the fire button, unless you use autofire or play ''Raiden III'' or ''IV'', which officially have autofire for this weapon. To summarize, red is your standard-purpose, blue is for concentrated power when point-blank is ''not'' an option, and purple/green is for blue purposes that also need you to hit things ''behind'' that strong opponent.
* BulletHell: Later games have denser bullet patterns, although the focus remains on fast aimed shots.
** This is the Cranassian red diamond's bread-and-butter every time you face it. It's not going to let you beat the game without surviving a ''torrential downpour'' of curtain fire.
* CapcomSequelStagnation: ''Raiden IV'' seems to be getting this, since it was ported to the Xbox 360. The newest update, ''Raiden IV: Overkill'', will be ported to PSN.
* CheckPoint: The Japanese version of ''Raiden'' has these.
** DifficultyByRegion: Other versions do not, and cause the player to respawn in place if killed.
* CombinationAttack: In 2 player mode, a very strong attack happens if both players shot collide with each other. It's a little unpredictable (the bullets of this attack fire in random directions), but at close range can waste bosses in seconds.
* ContinuingIsPainful: As with most shmups, you lose all your power ups when you die, although you can find a hidden Fairy that gives some of them back (and one time only). ''Raiden II'' and subsequent games are kind enough to spill a few power-ups from your ship on death, in addition to the Fairy, so it's not ''as'' crushing as it was in the original.
* CoolPlane: The titular ship.
* DamnYouMuscleMemory: The 360 port of ''Raiden IV'' offers a 360 mode that has all 5 stages plus two extra stages. At first glance that's the only difference, but if you're familiar with Arcade mode, you'll notice that 360 mode changes around the
* DifficultySpike: Usually occurs around the second or third stage.
* DivergentCharacterEvolution:
** In ''II'', player 1 starts with standard bombs, while player 2 starts with cluster bombs.
*** An odd example induced by porting tweaks: In the [[DifficultyByRegion Japanese version]] of the [=PS1=] port found in ''Raiden Project'' player 1 does not have {{checkpoint}}s and continues through the stage if they are killed and respawn. But player 2 gets checkpoints, going back to the last one upon death.
** In ''DX'', the player 1 ship moves faster vertically, while the player 2 ship moves faster horizontally.
* DoublePlay: The home ports of both ''III'' and ''IV'' have a mode where you can control both ships on the same controller.
* DualBoss: The first Boss fight of I and II are two tanks and two {{Spider Tank}}s, respectively.
** Two tanks again in III. In IV, the fourth boss is a pair of tanks that take to the air when they suffer enough damage.
* DynamicDifficulty: In I and II, if you mange to make it far without dying, the difficulty gets batshit insane. Tanks will fire very fast ''and'' [[ImprobableAimingSkills accurate]] shots almost as soon as they enter the screen!
** According to WordOfGod, this is traced to a common rule of thumb in the arcade industry at the time: if your game doesn't defeat the player in about 3 minutes (on average), you're not making money.
* EasterEgg: Seibu Kaihatsu's artists snuck quite a few into the first two games:
** Besides the cows example below, keep your eyes peeled in the first stage of ''Raiden'' for little people running around.
** A few seconds into ''II'''s second stage, look toward the left to find a dude obliviously doing jumping jacks in the street.
** Later in that stage, if you clear out a row of tanks along a certain road and haven't died up to that point, a red sports car will zoom by; [[VideoGameCrueltyPotential shoot it quick]] for big points. ''DX's'' Training stage gives you a similar spot with a chance to shoot multiple cars.
* EasyModeMockery: Clear ''Raiden IV''[='=]s Light mode and you're treated to an ending cutscene where the AirborneAircraftCarrier you took off from gets attacked ([[SoundtrackDissonance to the tune of the happy ending theme]]). Then you're told to try Original mode and the game ends without going to the second loop.
* EmbeddedPrecursor: The "Normal" course in ''Raiden DX'' consists of the first 5 stages of ''Raiden II'' with ''DX'''s scoring system applied.
* EverythingsBetterWithCows: Every game's first stage sends you flying over a farm with some cows. Cows that have ''animated sprites.''
* GrievousHarmWithABody: In II and DX, destroyed airborne enemies have a pretty good chance of crashing into the ground instead of just exploding in mid-air. If their landing point happens to be on top of a ground enemy, that poor enemy is going to be ''hurting'' (if not destroyed outright). Like with the things noted in SerialNumbersFiledOff, this is another element from {{Toaplan}} games, in this case Flying Shark/Sky Shark. In that game, if an enemy biplane was shot from far enough away, it would indeed crash-land rather than just explode—and destroy any hapless tank, patrol boat, or anti-aircraft gun that happened to be underneath.
* HarderThanHard: ''Raiden IV'' has Very Hard difficulty, which in turn is trumped by Ultimate difficulty. That is to say, Harder Than Harder Than Hard.
* HitboxDissonance: Later games in the series reduce the ship's hitbox to the size of most BulletHell hitboxes.
* LightningGun: Come on! Don't fool us with the laser-beam shape, Plasma! We know you to actually be lightning!
* MarathonLevel: The “training” campaign of Raiden DX is one long (about 15 minutes) continuous level.
* {{Nerf}}: The Lock-On Plasma Laser became the Proton Laser in ''III'' then came back in ''IV'' albeit with different coding.
** To be fair, the Lock-On Plasma Laser never was a good weapon to begin with.
* NintendoHard: The older games in the series show that just because it's not BulletHell doesn't mean it's any easier.
* OneUp: Most games in the series avert EveryTenThousandPoints; instead, you gain 1-ups by fulfilling some [[GuideDangIt obscure]] requirements in later stages. And you often get only one 1-up per game, so use those {{Smart Bomb}}s well!
* PainfullySlowProjectile: The "sniper" enemies' aversion of this trope is part of why the series is NintendoHard.
* ProductPlacement: The Genesis port of the first game adds a really hard level that appears after the credits. Beating it will show a message advertising one of Micronet's (the port developer) game, ''Heavy Nova''.
* RecurringBoss: The giant jet bomber that launches missiles that look kind of like smaller planes.
* RecurringBossTemplate: The first boss battle of the first three games pits you against a [[DualBoss duo of ground enemies]] (gun platforms in the first, [[SpiderTank spider tanks]] in ''II'' and giant tanks in ''III'') with the weaker one appearing slightly before the other. ''IV'' broke the trend by having a single spider tank instead.
** Also, there's the missile-carrying bomber in those games' second stages, and the giant aqueous vessel in the third stages (a battlecruiser in ''I'', a submarine in ''II'' and ''III'').
* RecycledINSPACE: Seibu's [[SelfPlagiarism own]] ''Viper Phase 1'' is this series [-IN SPACE-]! Its soundtrack is even unlockable in the Playstation port of Raiden DX.
* RegionalBonus: The US version of ''Raiden Project'' allows the player to turn off the checkpoint behavior in ''Raiden'', which was enforced in the Japanese version. On the downside, it [[DummiedOut dummies out]] vertical rotation, requiring the player to use a cheat device if they want to play the game on a vertically-oriented TV.
* SequentialBoss: The fifth boss of ''Raiden II''. First you destroy a space shuttle, then fight the fighter it was carrying, and finally face off with the orange jet housed inside it. Also kind of a ClimaxBoss, considering it's the last level on Earth.
** Also the Final Boss, which has you fire at the core of this giant purple obsidian-temple-thing, with more and more crap coming out of the temple ({{Mook}}s and bulletfire) as the battle goes on.
** Many of the bosses of the later games do this, as well as [[TurnsRed Turning Red]].
* SmartBomb: Unlike in many other scrolling shooters, the bomb's activation is not instantaneous; it doesn't provide the area of bullet cancellation until it explodes a second later. This often leads to prematurely firing bombs because being under a heavy storm of fast bullets will most likely result in death whether you have five bombs or none at all.
* SpiderTank: The first Boss(es) of II, Zelzelei Se Ful and Zelzelei Y Ek. You have to fight [[DualBoss two of them]] (thankfully, not at the same time, unless you're slow in cutting down the first one). One is also the first boss of ''Raiden IV'', Exerey Iss.
* SpreadShot: The default (red) weapon.
* StuffBlowingUp: This is one series that's proud of its explosion animations. Bosses do not go down quietly, visually and literally. The speakers on an actual ''Raiden'' cabinet really get the most out of the mighty '''BOOM'''.
** The artists of ''Raiden II'' poured an incredible amount of detail into basic Mooks being shot down, from the debris all the way to the craters and burning trees left when they hit the ground.
** ''IV'''s TrueFinalBoss truly takes the cake, [[spoiler:spending 24 seconds exploding to a crisp! (As it should, given how hard it is to reach.)]]
* TankGoodness: Out of all the futuristic war machines the Cranassian Empire throws at you, they sure do love tanks. Expect them in several varieties around every corner. [[spoiler:Hell, the red diamond's secret weapon in ''DX'''s hidden ninth stage is a ''giant tank!'']]
* TrueFinalBoss: ''Raiden DX'''s Expert course has one as shown [[http://www.youtube.com/watch?v=w-NTxIK-GYQ here]], if you can make it to the end in one credit. ''Raiden IV'' [[http://youtu.be/JR94VSgPb_0?t=9m54s has one at the end of the second loop.]]
* VideoGame3DLeap: ''Raiden III'' took the presentation approach.
* WaveMotionGun: Your blue powerup becomes this at max level pre-''III''. In ''III'' and ''IV'', it just gets steadily thicker.
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