%% Stealth Rock is not a Game Breaker. It is part of Complacent Gaming Syndrome. Please do not add them to this page.
%% Also, refrain from adding any competitive examples unless they've actually been banned by Smogon or Nintendo (Pokemon in the Overused Tier, for example Scizor, are NOT Game Breakers). Do not list mega evolutions or legendaries unless they've been banned.
%% If an example requires interaction with another game to break the story mode, it is not a Game Breaker; it falls under Gameplay Derailment.
%% Image removed per Image Pickin' thread: http://tvtropes.org/pmwiki/posts.php?discussion=1410800654087428100
%% Given the nature of this trope, any picture is likely to be JustAFaceAndACaption.
%% Do not add a picture to this page without running it through Image Pickin' for discussion.
->''Behold my powers! I am the strongest Pokémon in the world!'' [[note]] ([[ObviousRulePatch Type diversification]] and the progressive introduction of [[OlympusMons other contenders]] to the throne challenged this but only [[TheMaker Arceus]] ever outright exceeded Mewtwo in base stats totals; As of Gen VI, however, its Mega Forms have achieved a higher BST than even Arceus, making it true again for a time. It's now second strongest.)[[/note]]
-->-- '''{{SelfDemonstrating/Mewtwo}}''', ''Anime/PokemonTheFirstMovie''

{{Game Breaker}}s in the ''Franchise/{{Pokemon}}'' series. As the series has been going for 2 decades, it has a lot.


* Although it's an often overlooked mechanic of the game, if you take some time to do some berry farming, you will easily never have to spend money on status healing items ever again, as {{LetsPlay/Chuggaaconroy}} [[https://youtu.be/-0Nkv--bWn0?t=6m26s demonstrates]]. The best part is, since their introduction, berry farming has gotten more and more easier to maintain and more generous with berry returns with each passing generation. It easily reached it's peak in Gen VI, where not only are all berry planting locations gathered in one convenient spot, berry trees in that game can give an absolutely ''insane'' amount in return for what you put in. It's very possible to turn five or so Leppa berries or Lum berries into ''forty'' or so in one go.

[[folder:First Generation maingame]]
* The Psychic-types were notoriously broken in this generation. They only had a weakness to types of attacks that did below-average damage even super-effective, and those moves were available to very few viable Pokémon. Due to a bug, one of those types actually didn't affect Psychic-types at all, rather than do double damage. Making things worse, the most common type was the Psychic-weak Poison-type. The Psychic-type advantage was augmented by the Special stat governing both Special Attack and Special Defense. This meant that Pokémon with high Special, such as Psychics, were much more useful than Pokémon with low Special, such as Fighting. This issue was fixed in ''VideoGame/PokemonGoldAndSilver'' in later generations by separating the stats and introducing two new advantageous types.
* Wrap, Bind, Clamp, and Fire Spin. In the first generation, instead of preventing you from switching, they prevented the affected Pokemon from attacking, while dealing ScratchDamage every turn. Needless to say, this was changed in the succeeding games. The most broken part however was that getting free from them still cost a turn, so if the enemy was faster than you they'd get the chance to re-use Wrap, Bind, Clamp, or Fire Spin before you get the chance to respond. It also goes without saying, but X-Items and stat-boosting moves increase the potency of these moves.
* X Accuracy in the first games gave moves Swiftlike accuracy. This includes ''the [[OneHitKO OHKO]] instant death moves.'' The real dangers of this are because beating the eighth Gym Leader, Giovanni, got you the TM for Fissure, which could be used on a lot of final form Pokemon, like [[FragileSpeedster Dugtrio]], who could outspeed most Pokemon easily, and because OHKO moves could be used to defeat higher-level opponents, it made defeating the Elite Four (barring Lance, who could be defeated using a good Ice Beam user, which most Water Pokémon are) a piece of cake. The combination of X Accuracy and OHKO moves was ''so'' powerful that the mechanics for OHKO moves had to be changed in future generations so that they could never connect against an opponent whose level was higher than the user's level or increase in accuracy.

[[folder:Fifth Generation maingame]]
* In the ''VideoGame/PokemonBlackAndWhite'' main game, the Lucky Egg item. In previous games, this was an extraordinarily rare [[RandomlyDrops steal from Chansey]], but in this game, it is simply given to you free of charge about halfway through. It greatly increases the experience of the mon holding it, allowing you to gain levels at ridiculous rates provided you kept going through the tedium of redistributing it every time you switched your active Pokémon -- of course, it's totally worth it to outlevel the Elite Four without any extra LevelGrinding on Victory Road unlike the previous gens, and turn the game between getting the Lucky Egg and the Elite Four into one giant CurbStompBattle.
* A big one was the option for players to download both Mewtwo level 70 AND Arceus level 100 into Black and White from the Pokémon website. If you have both on your team, most of the in-game opponents won't stand a chance. Admittedly, the battles against Shauntal and Grimsley of the Elite Four and the battle with Alder (their 'mons are all in the 60s and 70s that go around) still require some potions on hand, but still, it's way easier than it'd normally be. And you were able to get Reshiram or Zekrom as well, depending on your version.

[[folder:Sixth Generation maingame]]
* If you thought the Lucky Egg in Gen V was a Game Breaker, just wait until you see the Exp. Share in ''X and Y''. Remember that crappy Exp. All from Gen I? Picture that, except it's actually GOOD. Long story short, it's a key item that while you have it on, ''the rest of your party'' gains EXP equal to half of what you had out gained. This item ensures that you won't know the meaning of the term "underleveled" before the second Gym. In fact, you won't even know the meaning of "grinding" for the rest of the game for that matter.
** You could be training your lower-leveled Pokémon while making no effort to train your Starter, and your Starter still levels up at a rapid rate. One could essentially get away with training more than six mons and not suffer because of the speed, making it perfect for [[SelfImposedChallenge Nuzlocking]].
** For that matter, the Lucky Egg is back. It's possible to break the level-grinding even MORE by giving it to one of your Pokémon without turning the EXP Share off, letting them grow twice as fast without even being in a battle.
** Combine those two with a Sweet Scenter to trigger repeated horde battles and...woosh. Prepare for your lead to get 3 or 4 k or even up to 5 or 6 k at times per 5 [=KOs=] and your other mons still get a ton. You may need a decent supply of healing items or to remain near a town due to things like Spinda hordes spamming Confusion and Hypnosis and Weepinbell hordes who love poisoning you, but it's still worth it.
** Capturing wild Pokémon now gives you half the experience you'd earn for defeating them. Not only do you no longer have to sacrifice potential experience to complete your Pokédex or expand your team, but with the right resources, capturing a Pokémon can be quicker and easier than defeating it.
* Pokémon-Amie can turn into another serious Game Breaker if you use it enough. You bond with your Pokémon by petting it, playing minigames with it, feeding it food and such. While that might seem like little more than what's needed to get Sylveon, if you get your Pokémon's affection high enough, you'll receive epic side effects in battle, such as gaining 20% more EXP in battle, surviving attack with 1 HP, avoiding attacks, and shrugging off status conditions. You'll be shocked and flattered when those effects happen in battle.
* Mega Evolution as a whole can shatter the games in half. Most Mega Evolved Pokemon have stats that match or even surpass most legendary Pokemon and often with much better abilities than their normal counterparts. You often get the ability to Mega Evolve your Pokemon long before you can get any legendaries and rarely do you face opponents with Mega Pokemon of their own to even the odds. The ones available to you in story are often the stronger ones like the Kanto starters, the Hoenn starters and Lucario (who along with Blaziken are banned from competitive play for how powerful they are).
* The [=DexNav=]. It allows you to actively search for any Pokémon you have caught on a route, meaning there is no longer a need to spent a lengthy amount of time searching for rare Pokémon. It also shows you the level, the first move, the potential (maximum Individual Value represented by a star), ability and held item of the Pokémon, meaning you can actively search for a Pokémon with great potential and unique moves and abilities (some of the moves can be Egg Moves and abilities can be Hidden Abilities). But the game breaker comes in the rare items they can hold - items they normally would not be found holding in the wild - specifically the ones held by Linoone and Pelipper. Linoone can hold Max Revive, which recovers fainted Pokémon back to full health. Meanwhile, Pelipper holds Lucky Egg, which multiplies Exp by 1.5 times, and could previously only be found on the ludicrously rare Chansey line. With Dex Nav, you know which Pelipper will have Lucky Egg. Farm Pelipper for six Lucky Eggs, slap them onto each of your team members, activate Exp Share, and break the game in its entirety. On the other hand, it is also the perfect way to train up multiple teams simultaneously without worrying about over-leveling your Pokémon.
* Cosplay Pikachu in Contests. The thing comes with nearly maxed contest stats and you need only to pump a few Pokeblocks into it to max them fully, then get the scarves for each type of contest. Then change Pikachu's costume to the right contest type, and winning is extremely easy. At least until maybe Master Rank.
* [=Omega Ruby=] and [=Alpha Sapphire=] are extremely generous with legendary Pokemon as LastDiscMagic for the main story. Let's go down the list, shall we? You get a Latias or Latios for free, and you can get the other one if you get a hold of an Eon Ticket through Streetpassing. You're able to get a Groudon or Kyogre that holds an item which allows it to change its form as soon as its sent out. You're also able to catch all four legendary golems, all three lake guardians, all three legendary beasts, and the Swords of Justice members. You can also catch either Lugia or Ho-oh (depending on the version), Heatran, Dialga or Palkia (version dependent), Giratina, Cresselia, Tornadus or Thundurus (version dependent), Landorus, Reshiram and Zekrom (version dependent), as well as Kyurem. Remember this is all LastDiscMagic for a reason. Most of these Pokemon can only be unlocked as soon as you deal with Groudon or Kyogre in the Cave of Origin near the end of the game.

[[folder:Pokemon Mystery Dungeon]]
* Starting as a Cyndaquil is potentially a game breaker due to learning SmokeScreen early on, a move that makes the target's attacks always miss. It sounds simple, but when used against bosses or making a hallway fight for monster houses, you can just attack without any worry of being hit back. Charmander also learns Smokescreen relatively early.
* Due to a programming oversight (no Pokémon in the first games was given a gender except for the main character), moves that caused the Infatuation status (Attract and the ability Cute Charm, at that time) were absurdly powerful, basically being a nigh-effortless way to ensure that enemies almost never got a chance to attack you. Imprison worked similarly without even being an oversight.
** In ''Gates to Infinity'', the status can affect everyone once more... but it's somewhat fixed because it properly has the 50% chance of preventing attacking.
* Due to the special properties of the Pokémon Castform and its signature move Weather Ball, a single Castform could do enough damage to KO any non-boss Pokémon in a single hit at low-to-middle levels, and at high levels, could even do the same to any boss Pokémon that didn't resist Fire or Water. This was only minorly {{nerf}}ed in the ''Explorers'' games; Castform now has a 'size' of 4, meaning only one can be on a party and at the expense of another Pokémon, but most normal dungeons don't need more than the single Castform at one time anyway.
* In Red/Blue, upon maxing their IQ (the ''Pokémon Mystery Dungeon'' equivalent of 'Happiness', boosted by eating Gummi items), Pokémon acquired the ability "Super Mobile", which allowed them to travel over water, lava, clouds, and even allowed them to bash through walls to make their own path with absolutely no penalty. In a {{roguelike}} game, this naturally causes most of the difficulty to soar right out the window. In the ''Explorers'' games, this ability was severely restricted to a single legendary Pokémon, Palkia, whom you can only obtain ''after'' the game's storyline, making it more of a BraggingRightsReward.
* X-Eye Seeds snap boss battles right in two. The AI will ''never'' attack while under this effect, unlike during Confusion, and Crosseyed status probably lasts the longest of any adverse status effect short of stat drops. [[MushroomSamba Eating an X-Eye Seed reveals that they cause the victim to hallucinate that everything looks like a Substitute.]]
* Also, several IQ skills on the right IQ groups to boost HP, PP, and other stats could be further combined with Three-Star "Exclusive Items" that buffed a particular Pokémon each (generally giving them Absorption against a type they're usually weak against, or putting them in permanent Light Screen/Reflect status). Not only that, but the effects of those items are ''shared among all Pokémon belonging to the same evolutionary branch!'' So for instance, Pokémon like Gallade, Hitmonchan, Vileplume, or Politoed could not only gain the buffs of their former evolutions, but also those of their counterpart(s), for a total of 4 buffs. And the Eevee family... it's actually averted with the Eevee family, since each item explicitly only grants its effects to Eevee and the intended user.
** Also, while in the ''Time/Darkness'' titles you had to combine specific items to net one, usually not even resulting in what you exactly wanted, in ''Explorers of Sky'', you can look up the item you're looking for in the shop, and swap ''any exclusive items'' you want to get rid of for the one you want, basically turning any Pokémon with a broad enough "family", through IQ grinding and item gathering, into an InfinityPlusOneSword!
** Want to top '''even''' this? Then bring along also the two-star equivalent of the Exclusive Item to get an even bigger stat boost, make your 'mon binge on stat-rising items like Life Seed and Iron, and keep in mind that some of the rarest Exclusive Items affect ''all the 'mons of the same Type''. Pair it with a double-type, and...you know the drill.
** Most exclusive items are quite useful without being game-breaking. But a handful of them are absurdly powerful. Snover and the Hoenn weather trio can use their three-star items to perform double attacks all the time, for free. A Tyranitar can bring a Rock Gem to permanently move at double speed, and can extend this ability to all Rock-type teammates, plus Cacnea and Gligar with their three-star items. And Celebi's three-star item essentially guarantees that it will never run out of PP, ever. Snover/Abomasnow deserve even more special mention because they can use Blizzard as a perfectly accurate, extremely powerful room-clearing move that hits twice.
* Multi-Hit attacks (Bullet Seed, Fury Swipes/Attack, Pin Missile). Due to the damage calculation in the ''Mystery Dungeon'' games being much different than the mainstream titles, these move actually hit as hard as most other attacks ''per hit''. The brokenness comes from the fact that the STAB bonus from the mainstream titles is also implemented in the Mystery Dungeon games, meaning with the right Pokémon (A Treecko with Bullet Seed and the Concentrator skill for instance), this can be quite lethal.
** Speaking of Bullet Seed: because of how damage mechanics work, it can perform up to five ranged attacks, each of which deal a great deal of damage by themselves. And if you happen to KO the 'mon in front of you? It ''keeps attacking'' the ones behind it until you either run out of moves or targets.
** If you think that's bad, try linking Screech with a multi-hitting move, like Meowth or Persian with Fury Swipes, and watch how fast you take your opponents down.
** The only downside to multi-hit moves was the [[UnskilledButStrong decreased accuracy of each individual attack]] (and even then, you could usually land one or two for good damage). Combine it with Meowth's [[WeakButSkilled Technician]] ability (increases the base power of "low-damage" moves) and a partner's [[SmellsSexy Sweet Scent]] (which lowers the evasion of '''every enemy in the room'''), and suddenly you're doing ridiculous amounts of damage with every turn. Unfortunately, Meowth was downgraded to a partner in [[UpdatedRerelease Explorers of Sky]], but accuracy buffs/evasion debuffs still synergize well with multi-hit attacks. Sadly, Fury Swipes actually doesn't work with Technician, which only activates on moves with 3 stars of power or lower.
* In the main ''Pokemon'' series, Protect makes you invincible to damage for one turn, and Sonicboom only does 20 points of damage regardless of the Pokémon's stats. In the Mystery Dungeon games however, Protect stays in play for multiple turns, allowing for multiple attacks while the opponent is helpless, and Sonicboom is a ranged attack that hits for 55 points no matter what. Also, unlike the original games, where most Pokémon could easily have 200+ health points at the end of the game, most Pokémon naturally won't even reach triple digits (100+ health points) at the later points of the game, so just imagine how devastating and frustrating 55 direct points of damage from a distance (especifically off-screen) would be.
* In ''Pokemon Mystery Dungeon'', unlike the main series, Pokémon possess both of their two abilities at the same time. This makes [[StoneWall Bronzong]] a top-class gamebreaker, because one of its abilities ([[PowerFloats Levitate]]) negates one of its only 2 weaknesses while the other ([[SuperToughness Heatproof]]) negates the other. Its awesomeness is greater when you consider that Bronzong already has high defenses to go against the other attacking types which Bronzong is not weak to, along with the fact that his moveset is ''very'' good with Psychic and Gyro Ball being only ''some'' of the great moves it can learn. Add to this mix the fact that his low speed from the main game series isn't a factor in these games, and you'll have no trouble getting through most places in the game.
* There was also Shedinja from the ''Pokémon Mystery Dungeon'' series, who unlike in the regular games where they were limited to 1 health point no matter what, ''were'' able to eat Sitrus Berries in order to increase its health maximum. Couple that with the Wonder Guard ability, and the ''Super Mobile'' ability in the first game which is obtained by eating enough Gummies to reach maximum intelligence, to see how destructive one Pokémon could ''truly'' be. It gets even better in Explorers when Shedinja gets an accuracy-boosting IQ class and Silver Wind as an egg move.
* Attacks that hit the entire room trivialize Monster Houses. While Earthquake will hit allies, the rest don't while still retaining decently high power. Silver Wind and Ominous Wind in particular have a secondary effect that gives them a small chance to boost all of the user's stats by one stages, and each hit on an enemy has a chance to activate it. Since Monster Houses tend to have 7+ Pokémon in them, it's highly likely that using either will grant the boosts at least once and make fighting any survivors much easier.
** Zapdos can be considered one since it learns Agility, Charge, and Discharge. Try linking all three of those moves in that order and see [[CurbStompBattle what happens to a monster house]]... Unless there's [[OhCrap an enemy with the Lightningrod ability in said monster house...]]
** If you're talking about room affecting moves, specific mention has to go to Agility which raises all Pokémon on the same team's speed greatly, and moves like Silver Wind which hit the entire room, and can power up all of the stats of the one who uses it.
* Charizard in the [[BrutalBonusLevel dungeons that de-level the player to Level 1]]. A Level 1 Charizard starts off with Heat Wave, a decently powerful [=STAB=] attack that also hits entire rooms, heavily alleviating much of the challenge of those dungeons.
* Scizor in the Explorers games. To start off, it has the attack stats of a god, and [[GlassCannon although it's natural defense stats leaves some room to be desired]], it still has the fantastic Bug/Steel type, giving it only one major weakness and plenty of resistances, and even its mediocre defenses can be covered by increasing it with sufficient drinks and gummies. Secondly, its movepool is also huge, allowing it to take on almost any type or dungeon reliably, and also carries Agility, which can turn almost any boss into a joke thanks to the multiple turns it grants to your whole team. Additionally, it can also learn Silver Wind, a move that hits an entire room at once, thus tearing the dreaded monster houses to shreds. All of the above alone is enough to make Scizor an extremely versatile pokemon that would be valuable on almost any team, but what truly pushes it to game breaking levels is its ability, Technician, which gives a massive boost to any move with a base damage under a certain threshold. Technician-boosted weak attacks are significantly STRONGER than unboosted "strong" ones, so with the right moveset Technician essentially gives Scizor a free attack boost, including the mentioned Silver Wind and Bullet Punch. Add in Agility and almost every non-Fire type enemy or boss(es) won't even be able to touch it.
* The abilities Chlorophyll and Swift Swim, which in the main games boosted speed under Sunlight and Rain (respectively). However, since speed doesn't work in the same way in these games as it does in the other games, they had to figure out some other way to have the ability manifest itself. Of course, this comes in the form of having your Pokémon attack twice in the same turn for the PP cost of ONE attack. Now combine this with either Groudon or Kyogre, an already broken move like Heat Wave, and the fact that Fire/Water moves get a boost in that weather...
* Then there's Mirror Move. In the mainstream games, it's simply a move that allows you to replicate your foe's move; rather gimmicky and not very useful. In Mystery Dungeon, however, it acts as a Protect--while simultaneously reflecting every move that hits you back at the foe (including status-inducing moves). Not only does this last for several turns, but the reflected moves also factor in types. If you started with a Torchic, simply use Mirror Move on Palkia and watch it OHKO itself with a reflected Spacial Rend. Fantastically useful in monster houses and any multi-boss fights. It's a shame that enemies don't grant EXP if they KO themselves.
* Drifblim is a terror to behold. Thanks to Unburden, it gets its power instantly doubled as long as it's not holding an item. Two repeated Ominous Winds will destroy most Monster Houses. A double helping of Defog + Ominous Wind will ''sterilize'' them. Beware, though, because enemy Drifblim and Drifloon won't hesitate to use this trick against you.
* In a game where all base stats might as well be equal, who's bound to be the main beneficiary? Smeargle. Besides running grossly overpowered moves like Mirror Move, Spacial Rend, and Mind Reader + Rollout, it can, along with Cresselia, bring two copies of Lunar Dance (the only PP restoration move) into an exploration, granting infinite PP to the entire team. Sketching a teammate's moves isn't even difficult, only requiring a Blinker Seed and some tweaking of the Nontraitor IQ skill. And just when you thought Smeargle couldn't possibly be any more broken, recall that it has the Technician ability.
* In ''Gates to Infinity'', picking Axew as your hero or partner may as well be an easy mode enabler, as its first two level-up moves are Dragon Rage and Double Chop. The former is a fixed damage move capable of one or two hit KOing most early game Pokemon, while the latter is an extremely powerful multi-hitting move that's literally the only melee range attack it'll ever need. Add in the fact that it's a Dragon type, and thus resists numerous common types and is resisted by almost nothing, and there's very little that can stand up to it.
** Excadrill are just as overpowered here as they are in the regular game. They learn both Swords Dance and STAB Earthquake at a relatively low level, and their pre-evolved forms aren't that difficult to find (they can be found in the first dungeon). Combine this with its already ridiculous Attack, and you've got something that deals serious damage, even to ''Flying-types''. They're so stupidly powerful that, unless you know what you're doing, your team's Excadrill will one-shot everyone, [[TotalPartyKill including your teammates]]. And if that wasn't enough, Sand Rush allows the user to move twice in one turn if sandstorms are brewing. Dungeons that force you with only one party member? No worries, just send in the mole. It can make short work of just about ''everything''. The only things it ''can't'' handle are [[BrutalBonusLevel the Path of No Return and Slumbering Cave dungeons]], since they force all Pokémon to level 5, and their movepools are reduced to level-up only.
** Companion Mode is quite powerful here, if you're patient enough. When in Companion Mode, the story stops completely, and you get to play as a party of the Pokémon you've recruited. Here, you can build up Pokémon Paradise and accumulate massive amounts of resources and items, at the start of the game! The only limits to this are your patience and the fact that better dungeons/missions will be unlocked as the main story is progressed. What really makes this powerful is the fact that there is a shared experience system in effect. All EXP that is earned is shared by all Pokémon, ''even the ones in Paradise and the story characters''. With enough time, your story Pokémon will be vastly overleveled.

[[folder:Pokemon Rumble]]
* ''Pokemon Rumble U'', if you actually pre-ordered it, comes with Black/White Kyurem. These two, once you get their passwords in the game, are unstoppable killing machines that destroy anything bar bosses in a single shot. That is, until the further levels, but it's still amazingly easy.
* ''Pokemon Rumble Blast'' (the 3DS version) also has a password system, accessible after the second town. Taking a few minutes to look for codes on the internet and entering them gives you steadily increasingly powerful Mons depending on the area. They are all at a set level and usually know moves you couldn't learn until [[spoiler: Axle Town]] through the random move machine. All you have to do after entering the code is to find them in the overworld and defeat them, and for their level and obtain point in the game, they are absurdly powerful(read: Victini/V-Create, Tornadus/Hurricane, Zoroark/Foul Play). And once you beat the game, you can access more codes for OlympusMons like Groudon, Dialga, and Lugia. For free.
** And if you were patient enough to continuously beat levels to access that 5% chance, one of many OlympusMons is yours, depending on the level. Most are faithful to their main series counterparts (Darkrai having high Attack, low Defense, or Lugia having low Attack but high Defense), and some even have both maxed out. And most come loaded with their SignatureMove from the start (or a high power attack if they lack one), just to make the rest of the game, [[NintendoHard barring the EX Battle Royales]], a complete joke. And even then, if you do beat the EX Royales and keep searching through specific levels... say hello to '''[[OlympusMons Arceus and Mewtwo]]'''.

[[folder:Trading Card Game]]
* The Game Boy Color version of the ''VideoGame/PokemonTradingCardGame'', faithful to [[TabletopGame/{{Pokemon}} the original game]] has Imakuni? was a GameBreaker. He was weaker than all the AI characters, but if you defeated him (which was quite often), he gives you an unheard-of four booster packs. This makes racking up cards rather easy.
** There's also Pokémon like [[http://cdn.bulbagarden.net/upload/d/de/HitmonleeFossil7.jpg Hitmonlee]] who could attack your lead Pokémon with a powerful move, or your benched Pokémon for 20 points of direct damage, easily defeating first form Pokémon with really low health in one or two turns, while it had enough health to last for a while if you didn't have a powerful psychic Pokémon to counter it. It's also an AIBreaker in the video game, as the AI will be unlikely to give energy to their active Pokemon if Hitmonlee will defeat it in one hit (which his 50 damage High Jump Kick may well do).
** Similar to the above example the "[[FanNickname Haymaker]]" cards which are basic Pokémon cards with HP comparable to most evolution cards and low energy costs; Scyther, Hitmonchan, and Electabuzz can give you a massive advantage at the beginning of a match, and then there's what happens if you have four in a deck...
*** The Pokémon Trading Card Game underwent SequelEscalation for each generation that was released, plus another for [=HeartGold=] and [=SoulSilver=]. It's reached the point where the old Haymaker deck is easily overpowered. This is due to an increased emphasis on evolution in that evolved Pokémon get lower Energy costs for greater effects, more Pokémon capable of hitting the Bench, vastly improved Trainer cards (since then split into Trainers, Supporters, and Stadiums) that can easily search for cards of your choice from the deck or discard pile, and a trend away from Energy being the requirement for attacks, instead leaning towards other effects on the field. Together, this has resulted in a frenzy pace, most tournament decks refined to be fully set up in 1 turn, or 2 at most. For instance, Gyarados has an attack that does 30 damage for each Magikarp in the discard pile. A popular deck is designed to use Broken Time Space to [[MagikarpPower evolve a Magikarp on the first turn]] (bypassing a rule prohibiting this), find the 3 remaining Magikarps and discard them, attach an Expert Belt (which boosts attack power by 20), and use this move for 110 damage. Also, this attack requires no Energy at all. Compared to decks like these, the Haymaker is but a light jab.
** The Team Rocket booster packs, full stop. These had such Pokémon as Rocket Blastoise who could use its "Rocket Tackle" attack for 40 damage, and flip a coin which if it was called right, negated ''any'' damage from the opponent in the next turn including status effects, all for reducing its health by 10 HP, Rocket Charizard who had an attack called "Continuous Fireball", which for ''one'' fire energy it could flip a coin until it got tails, and the attack did ''50 points of damage to the opponent for each heads it got'', and the best part is that most of these overpowered cards were ''common cards''. The rare cards were even worse like Rocket Dragonite who had a power that allowed you to put two Pokémon on your bench at once while it was in battle, and a Trainer Card called "Here Comes Team Rocket" which made both players play the game with their prizes face up, and eliminating the random possibility of picking a weak prize after a victory while thinking of a proper way to use your prizes in any order you want, while keeping an eye on your opponent's possible prizes at the same time.
* The Pokémon SP were pretty broken in general thanks to their speed and the sheer number of options they had. There were trainers that reduced their energy costs, negated opponent Poké-Powers on their turn and even returned a Pokémon SP to your hand without any drawbacks. There was even a card to search your deck for these trainers. The worst Pokémon of all was almost definitely Garchomp C LV.X. It leveled up from a basic Garchomp C, and when it went into play it could completely heal all of your SP Pokémon, has no retreat cost, and with the right combination of cards it could hit any opposing Pokémon for 80 damage for one energy card. You could have a Garchomp C on your bench with nothing attached and get to taking out a vital support Pokémon on their side in a single turn.
* '''Lysandre's Trump Card''', a supporter card which returned the entire discard pile back to the deck. This single card allowed players to run through their entire deck with minimal problems, and extended gameplay by effectively eliminating the deck out win condition. As a result, it was the first card to be banned from competitive play in over 15 years, and only the third to be banned in the history of the franchise.
* Next Destinies Shiftry was the next card to be banned. Its Ability Giant Fan could force the opponent to return the targeted Pokémon back to the deck, along with all other cards attached with it, whenever one of the player's Pokémon evolved. ND Shiftry could be combined with a variety of other cards, especially Forest of Giant Plants (instantly evolves Grass-Energy Pokémon in play), to be able to use Giant Fan multiple times in a single turn. This often resulted in the player using ND Shiftry to win on the first turn before their opponent could do anything.
* The first two cards to be banned were Sneasel and Slowking from Neo Genesis. Sneasel had the Beat Up attack which, for only two Darkness energy, flipped a coin for every Pokemon you had in play and did 20 damage for each heads. Given that this equates to 6 flips most of the time and that Darkness energy had the additional effect of adding 10 damage to your attacks ''per energy'', this meant an average of 80 damage for 2 energy, at a time when 30 for 2 was considered good. On top of that, it also had no weakness and free retreat, and was a Basic Pokemon. Slowking ended up broken due to a BlindIdiotTranslation: its ability Mind Games caused your opponent to flip a coin every time they tried to play a Trainer card. If tails, not only did the card fail, but it was placed on the top of their deck, effectively shutting down their draw next turn. Why was this so bad? Because the English translation of the card forgot to include the phrase "this ability only works when Slowking is your Active Pokemon". As a result, you were able to fill your bench with 4 Slowkings and give your opponent only a ''1/16 chance of playing Trainer cards''.
* As a general rule of thumb, most Pokemon EX are overpowered due to them almost always being ''Basic'' Pokemon as opposed to fully evolved (Stage 2) Pokemon. The EX 'Mons have high HP, strong attacks and low to medium energy requirements, and some can switch Pokemon or heal damage making them tough to get rid of. The Gamebreakers however are the Mega EX Pokemon, who can be placed on top of EX Pokemon or regular Pokemon, and have massive HP reserves and insane attack power. And consider you can have more than one EX in your deck. Some decks just revolve around getting 4-5 EX on the bench, loading them up with energy, then sweeping the opponent.

[[folder:General Competitive Multiplayer]]

[[AC:Generation I:]]
* The quote above is from Mewtwo, the only Pokémon that has been banned from competitive battling ''ever since Pokémon was created''. The original GameBreaker. Back in Generation I, Mewtwo effectively had a BST of ''744'' [[note]]counting the special split[[/note]] making it not only higher than every other Pokemon at the time, but higher than every other Pokemon ever released until generation 6 (including [[OlympusMons Arceus]]!). To make matters worse, it was a Psychic type (which has its own GameBreaker entry above), and a wide move-pool to perfectly use every single one of its stats. From [[KillItWithIce Blizzard]], to [[FrickingLaserBeams Hyper]] [[WaveMotionGun Beam]], to the resistance-enhancing Barrier, [[TakingYouWithMe to the last-ditch]] [[SuicideAttack Selfdestruct]], to even the feared (and not banned back then) Double Team combined with Recover. The icing on the cake? ''Amnesia''. Which in Gen I boosted its Special by two stages [[note]]Which counted for ''both Special Attack and Special Defense''[[/note]]. And when you combine it with high-power Special moves like Psychic, Thunderbolt, and the aforementioned Blizzard, you've got a nigh unstoppable Pokemon of mass destruction. To quote Website/{{Smogon}}:

--> ''"[[http://www.smogon.com/rb/pokemon/mewtwo RBY Mewtwo is the single most powerful Pokemon in any generation. Nothing even comes close to the raw destructive power of this thing.]] [[PurposelyOverpowered That's all there is to be said about the joy that enters the heart of a 6-year-old when they capture the Uber and can truly call themselves a Pokemon Master.]]"''

--> ''"'''Checks and Counters''': [[ImplacableMan Nope. Nothing can fully counter a Mewtwo;]] [[http://www.smogon.com/rb/pokemon/mewtwo some can make it think twice, though.]]"''.
* Mew, the only other Pokémon banned from Gen I has [[MasterOfAll 100 Base Stats on everything]], which is incredible for its time, meaning it was [[LightningBruiser extremely bulky, fast and strong]]. This, combined with the Psychic typing and the ability to learn [[ConfusionFu every TM]] made Mew extremely unpredictable. However, due to PowerCreep in Gen V, Mew's no longer considered a Game Breaker, and its main use is to beat Stall.

[[AC:Generation II:]]
* Perish Trapping (using Perish Song to faint the opponent in 3 turns and Mean Look/Spider Web so they couldn't escape and nullify the effect) was a very effective strategy due to the primarily defensive nature of the metagame. Combined with a sleep-inducing move, non-offensive Pokemon would be rendered helpless against their imminent demise, which led to sleep-inducing and trapping moves being banned on the same moveset by Smogon. The faster pace of the metagame in later generations would render this ban unnecessary and limit the effectiveness of Perish Trapping in general, but this is likely why Misdreavus, the most notable user of the strategy, could no longer learn Hypnosis in later generations. It's also the biggest part of the reason why Mega Gengar became so widely despised by the fanbase and quickly gained a reputation as one of the most ridiculously broken and abusive Pokemon ever.
* Ho-Oh is a physical monster with far too much bulk for something that hits that hard and has that good of a movepool; indeed, part of the reason why Ho-Oh is so nasty is because of how much sets it can run well, making dealing with it one hell of a gamble. Gen V also gave it [[HealingFactor Regenerator]] as a Hidden Ability, allowing it to annihilate things with [[CastFromHitPoints Brave Bird]] all day and then just switch out when its health gets too low for its liking, as well as offering some insulation against Stealth Rock, which it has a 4x weakness to. Gen VI gave it another incidental boost with the introduction of the Fairy-type, as Ho-Oh resists Fairy attacks; additionally, Defog's newfound ability to clear everyone's entry hazards makes Stealth Rock even less of an issue and gives it even more chances to plow through everything.
* Lugia, meanwhile, is quite possibly the best wall in the game. Not only is it UNBELIEVABLY bulky, but it's also extremely fast and has even more options than Ho-Oh. It can outstall almost anything, be it through sheer attrition, myriad status effects, the multiple forced switching moves at its disposal (which is fantastic when dealing with things that require setup), or really, just whatever the hell it feels like. Gen V gave it Multiscale, which makes it nigh impossible to faint if you don't break it beforehand since the ability cuts damage taken by half when at full HP. If it wants to just outlast things and cripple the offensive capabilities of the opposing team, it still has Pressure, but if it wants to never, ever faint and force things to pull out all the stops to defeat it and then wind up getting forced out for their trouble, Multiscale is your best bet. Stealth Rock is still an issue, kinda, but with Defog as of Gen VI, it's totally manageable.
* Celebi, similar to Mew, is extremely bulky, and can learn moves such as Leech Seed, Recover or Heal Bell, meaning it's incredibly hard to cause it to faint. One would think having 7 weaknesses ([[AchillesHeel One of them double]]) would balance it, but Bug-type attacks were pretty rare (The only users were Heracross, which is weak to Psychic ''and'' is outsped by Celebi, and Forretress), Ghost-type attacks were nonexistent, and Poison was weak to Psychic. Fire- and Dark-type attacks were rare too(Only used by Houndoom, [[TakeAThirdOption and Celebi could learn Baton Pass to prevent Houndoom from Pursuit-trapping it]]), and it could easily survive an Ice Beam from most Pokémon. The only attacks that had a shot at beating Celebi were HP Flying from Dragonite and Drill Peck from Dodrio (Which weren't used at all). This basically meant that Celebi could switch in on anything, force it out, and then switch again almost unharmed. It was so bad, some people had to force HP Bug on some Pokémon to prevent Celebi from coming in for free.

[[AC:Generation III:]]
* ''[[VideoGame/PokemonRubyAndSApphire Ruby and Sapphire]]'' gave Wobbuffet the Shadow Tag ability, which ''[[YouWillNotEvadeMe prevents the opponent from switching]]'', and Encore to its movepool. Forcing the opponent with Encore to repeat their moves while preventing them from switching is possibly one of the most sadistic strategies ''Franchise/{{Pokemon}}'' has to offer. If the opponent decided to play around this by using a non-damaging move like Swords Dance, Wobbuffet would happily switch out to another party member, which then had a free turn to set up any stat buff it wanted, while the opponent was still Encored and helpless. And by giving Wobbuffet the Leftovers item[[note]]which gives it 1/16-of-maximum-HP recovery every turn (note again that Wobbuffet has near the best HP in the game)[[/note]], it could stay on its feet almost indefinitely. This gives Wobbuffet the dubious honor of being the first non-legendary Pokémon to be banned from competitive play. And the second? Wynaut. Wobbuffet's ''baby'' form. If that wasn't bad enough, imagine two Wobbuffet. both having Leftovers, facing either other. Neither can attack except with Struggle (and remember, Wobbuffet also has rock-bottom attack power), and neither switch out. [[UnwinnableByMistake Literally, a battle no one can win.]] This actually caused Nintendo to change the rules of official tournaments, first banning use of Leftovers on Wobbuffet, then changing the format of all subsequent tournaments to doubles, where Wobbuffet is mostly dead weight[[note]]it'll prevent opponents from switching out, but since it can't force opponents to target it, an opponent will focus their attacks on Wob's partner, rendering its countering abilities moot while forcing its partner to fight two-on-one[[/note]].
* Kyogre gets special mention; unlike Groudon who's a ''Ground''-type Pokémon with an ability that raises ''Fire''-type moves, Kyogre's a ''Water''-type Pokémon that has an ability that raises ''water'' type moves, ''and boosting its Water-type moves along with STAB!'' [[ShockAndAwe Oh, yes, and it can learn Thunder]], which has 100% Accuracy during rain, not to mention Ice Beam for the Dragon-types. Considering that its Special Attack is slightly lower than Mewtwo with considerably better bulk to compensate, you can give it a Choice Specs to boost its Special attacks ''further'', or Choice Scarf to raise its speed to the point where only a few Pokémon without Choice Scarf itself could exceed it to see how devastating it is in battle.
* Groudon is no joke either. 150 base attack, and 140 base defense paired with solid 100 base HP makes it a very sturdy tank that even Rayquaza's Outrage can't break easily. He has a crazy movepool including Thunder Wave, Stealth Rock, Rock Polish and Swords Dance. Oh and he's a Ground-type meaning he gets STAB Earthquake and an immunity to Thunder Wave. If you let Groudon get a boost, you're basically garanteed to lose. To top it all off, Groudon's ability Drought causes intense sunlight, boosting the power of Fire attacks and some Grass moves, meaning it can murder Ice types with Fire moves or use Solarbeam (skipping the charge phase) to murder any Water types, covering 2 of its weaknesses. Not to mention that while Kyogre's Drizzle weakens Fire-type moves (which Kyogre already resists), Groudon's Drought weakens Water-type moves (aka, a major weakness to Ground-types). Since it reduces the power of Water attacks by 50%, it makes a "super effective" attack hit like a normally effective one, so the only things that can effectively hit Groudon super-effectively in harsh sunlight are Ice and Grass type moves.
* Rayquaza. A Flying Dragon with 150 offense on both sides, at a downside of a not so high 95 speed and decent 90 defense and Special Defense with access to the dreaded Swords Dance + Extremespeed combination and Dragon Dance. It's able to become a Wallbreaker as well. Even if you try to use a Steel-type to wall Rayquaza, that might not help at all, since Rayquaza gets V-Create. [[NukeEm Yes, V-Create, Victini's signature move which runs off]] '''[[NukeEm 180 base power]]'''.
* Deoxys has 4 forms, and all of them are Game Breakers on their own way:
** The Attack form is the definition of GlassCannon, with 180 offenses (The fifth highest Attack, and third highest Special Attack), but 20 defenses (The second lowest Defense and ''the'' lowest Special Defense). It also has a whopping 150 Speed, meaning it's fast enough to run Attack boosting Natures and still outrun the Base 130. You're going to need either a Pokémon with a Choice Scarf or a priority to defeat it, and even then it's not even a surefire way to do it, since it could be carrying a Focus Sash.
** Deoxys-N is similar to the Attack forme, but with less offense and slightly more bulk, but not enough to matter. This causes it to be considered awful in games where Deo-A is allowed, but fills the same spot it would have in ones where it's not.
** Deoxys-D is broken in a more indirect way. It was extremely devastating when used as a Hazard Setter, as it forced a lot of switches and therefore free turns for Spikes stacking. It was bulky enough that only a handful of Pokémon could OHKO a max HP Deoxys-D[[note]]and this could be avoided anyway by using defensive [=EVs=][[/note]], and it could not be Taunted easily, as it could hold a Mental Herb or use Magic Coat to prevent Taunt. The fact that it guaranteed at least Stealth Rock and a few Spikes layers made it the perfect offensive supporter, giving too much power to offensive teams.
** Deoxys-S was extremely versatile. It could be used as a Suicide Lead to set Stealth Rock, Screens or Spikes to abet hyper-offence similarly to Deoxys-D, as well a Revenge Killer that could outspeed almost every Pokémon ''with boosted speed'', and even an anti-Lead.

[[AC:Generation IV:]]
* A major difference in Gen IV and V, and even somewhat in Gen III compared to the first two generations, is that with the official tournament formats shifting to non-single battles, now Pokémon and abilities and moves are not really balanced toward singles 6-on-6 as they were before. This leads to stuff that, while fine for doubles/triple battles where a single Pokemon risks being a focal point for attack which could minimize its impact, in singles that same mon becomes really powerful since it can last longer in singles to have a bigger impact.
* Generally speaking, the fourth generation saw Dragon-types heavily buffed. The new move Draco Meteor, a 140 base power special Dragon-type move, was learn-able by every fully-evolved Dragon and basically [[OneHitKill one-shot anything not a Steel-type]]. Outrage was also buffed, becoming one of the deadliest attacks in the game in Generation IV with an increase in power from 90 to 120. With the advent of the physical-special split, Dragon Claw and Outrage went from being special moves to physical, letting Salamence, Dragonite, and Garchomp run STAB Outrage off their superior Attack stat. The extremely popular buffing move Dragon Dance, widely distributed among Dragons, could now be used to boost Dragon-type moves. Dragon-types other than Garchomp could now run their choice of physical, special, or mixed attacking sets, which undercut their traditional counters, especially when factoring the new Choice items[[note]]boosting one of Attack, Special Attack or Speed by 50%, at the cost of freedom to switch moves[[/note]] By the end of Gen IV, Garchomp, Salamence, Latios, and Latias were all KickedUpstairs into Ubers, resulting in Dragonite and Flygon being the only real such threat left in Gen IV Smogon standard.
** The Latis had an extremely good typing, both offensively and defensively, along with great bulk, a ridiculous amount of power, and an amazing Speed tier. Both could drop a Specs-boosted Draco Meteor on anything and do ridiculous amount of damage, ''especially'' Latios, while it was incredibly easy to run Semi-Stall teams with both an amazing defensive core and tons of offensive pressure with Latias. Even when they were unbanned in Gen V, Soul Dew is still banned, as it provides them with a free Calm Mind.
** The main thing that made Salamence broken was that it could easily switch in due to its good resists, Intimidate and good Base 100 Speed and force the opponent to guess whether it was running a Dragon Dance set or a Mixed Set, both of which had wildly different counters and could easily make you lose two Pokémon if you guessed wrong. Even if you guess right, you still take a brutal amount of damage and maybe even lose your counter to Draco Meteor or a coverage move such as Brick Break or Earthquake. ButWaitTheresMore There was a 'third', bulkier set, that could easily set up on Scizor, its most common revenge killer. As for the DD Set, its 100 Speed is what pushed it over the top. Now, Scarf Jirachi or Flygon need to win the Speed tie first, while Scarf Heatran doesn't stand a chance. It's for this reason that Dragonite wasn't considered as broken, as it's slower and has lower offensive Stats.
** Garchomp could easily one of the most powerful non-legendary Pokémon ever created. It possesses an excellent Attack, one of the best possible offensive typings in the game[[note]]before Generation 6, there were only three Pokémon (Bronzong with the ability Levitate, Shedinja, and Skarmory) who could resist both the Dragon and Ground type attacks Garchomp gets a STAB-boost for, all of which are weak to Fire attacks Garchomp can also use[[/note]], very good Speed, and more bulk than Swampert (a ''defensive'' Pokémon). The flagship Garchomp set contained the Yache Berry, which cut the effectiveness of Ice-type attacks, Garchomp's only major weakness. This allowed it to get a Swords Dance off and guaranteed one or two [=KOs=] before Garchomp goes down. An even more hated version was [=BrightPowder=]-Chomp which, combined with the Sand Veil ability[[note]]opponent accuracy is cut to 80% in a sandstorm, ever-present in this generation, and Brightpowder subtracts an additional 10%[[/note]] meant that with just Tyranitar in your team, attacks hit him a maximum of 72% - which you could happily abuse with Substitute until you dodge an attack, Swords Dance, and sweep. This is all made even easier because Garchomp can switch-in and force out most Pokémon because of how impossibly threatening it was.
* Dialga's Steel/Dragon typing is one of the best defensively on top of having great physical bulk. Defensive sets could still hit back hard without investment, offensive sets could take hits easily while being hard to wall, and both could provide team support thanks to it being able to learn Stealth Rock.
* Palkia's Water/Dragon typing gives it exactly 2 weakness in Dragon and Fairy and it hits the 100 Speed Cup, meaning it can comfortably run items other than a Choice Scarf. Like Dialgia it is hard to wall between its powerful STAB attacks and coverage and can run more defensive sets that are hard to break while still hitting back.
* Giratina. It has two forms. The first one is a StoneWall capable of walling 90% of the game along with preventing the use of Rapid Spin, while the other one is a MightyGlacier (10 Speed points short of being a LightningBruiser) who manages to be a GameBreaker despite the fact that it's unable to hold an Item to boost its average offensive Stats.
* Manaphy in this Gen and in Gen V, albeit for different reasons. in Generation IV, it had two sets: An offensive Tail Glow set, with enough Speed and bulk to easily pull of a Sweep, and a bulky Calm Mind set, which made it nigh-indestructible. Generation V, meanwhile, made it even more of a LightningBruiser, since it could easily set up with Tail Glow/Calm Mind, use Rest in the Rain to get rid of Status and get back to full Health only for Hydration to wake her up, and then pull of a Sweep with absurdly powerful Scalds or Surfs that were also boosted by the Rain. Manaphy also had key resistances and coverage in Ice Beam and Energy Ball that allowed it to rip through Stall teams with ease.
* Arceus also deserves a mention. A 120 base stat spread in everything, a move-pool only rivaled by Mew and [[MegaManning Smeargle]] and the ability to change its type by holding one of seventeen Elemental plates makes it a very versatile and dangerous Pokémon that is able to duplicate almost every Pokémon in the game and do the same roles with the same level of efficiency all in one package. It effectively rivals Xerneas and Mega Salamence in term of brokenness.
** To show how insane Arceus is statistically, it has a higher stat total than any other Pokemon except generation 1 Mewtwo (see above). By comparison Kyogre and Groudon only win in attack and their respective defensive side (physical and special respectively). But on the attacking side, Arceus has 120 Speed on its side, significantly faster than both since that means even with very little [=EVs=], Arceus is faster than either with the maximum speed they can reach. It also means the resident StoneWall Lugia is slower than Arceus. On the defensive side, despite the differences, Arceus is only slightly less bulky on the weaker defensive stat. So little that it's no matter at all. Oh, and did we mention that by forgoing some hold item it can change its type AND getting boosted STAB at the same time? Let's not start talking about its notable moves.
* Darkrai is brutal itself. 135 Special Attack, while not as ridiculous as some of the other things it'll be dealing with, is still very impressive, and 125 Speed is one of the fastest available. Its movelist, however, is what pushes it over the edge. First off, it has a very useful SecretArt called Dark Void, which is an 80% accuracy Sleep-inducer (most sleep moves have ''far'' worse accuracy). Coupled with its excellent Speed, there isn't much that it can't get the jump on, and its Ability causes damage every turn to sleeping foes and acts as a weaker-but-free Nightmare. Its main weakness is its frailty and vulnerability to revenge killers, but it offsets both by being able to cause enough damage to create an insurmountable advantage by the time it has been knocked out.
* Shaymin-S is a Togekiss on steroids. Its SignatureMove, Seed Flare, has a 40% chance of reducing Special Defense by 2 stages. It wouldn't be so bad on its own, if its Ability was anything other than [[LuckBasedMission Serene Grace]], which doubles that chance. This, combined with its blistering Speed means that nothing can switch in on it, as it has to take two hits, gamble for the 20% chance of their Sp. Def ''not'' being lowered (Yeah, good luck with that 4% chance), and hit Shaymin-S. For more LuckBasedMission shenanigans, It also gets Air Slash, which also has its 30% chance of flinching doubled, and Shaymin-S is also really really fast. Shaymin-S proved to be such a bother that the vote to ban it to Ubers was an ''unanimous'' vote.

[[AC:Generation V:]]
* Reshiram, the Cover Legendary for Pokémon Black, benefits from completely unresisted STAB (Due to Turboblaze, Mold Breaker with a fancy name) outside from Azumarill and Diancie, and pairs up with Groudon in the same way Palkia pairs up with Kyogre. Zekrom, on the other hand, benefits from its extremely high Attack and its powerful Bolt Strike to be a very effective Wallbreaker.
* In Generation V's metagame, one playstyle on online simulators provoked quite a bit of outrage; Rain teams. Thanks to the Dream World being able to unlock Pokémon with unique hidden abilities, Politoed got Kyogre's Drizzle for a Dream World ability, summoning permanent rain storms. Combined with the speed-doubling ability Swift Swim and Water's fantastic defense and neutral coverage, the meta-game was completely annihilated by a blitz of obscenely fast, strong, and bulky water Pokémon, with Kingdra, Kabutops and Ludicolo being considered Uber-level fighters. Add to that Manaphy, who can maximize its special attack with two turns of setups and is immune to status in the rain (letting it instantly heal with Rest) and it's no surprise that Rain was completely dominant in the Generation V metagame until Smogon declared it illegal to utilize Drizzle and Swift Swim together.
* A newcomer to Generation V's Uber list for {{Website/Smogon}} is Blaziken, the first starter to make it to that tier. Its new Dream World Ability, Speed Boost, raises Blaziken's normally mediocre speed by one step every turn (and it can use Protect to guarantee that first crucial turn), and the retooled Hi Jump Kick grants Blaziken a devastating STAB move that doesn't lower its stats. Under the sun, there are few things that can switch into Blaziken's Flare Blitz without promptly being obliterated, especially after a Swords Dance. Its biggest power is the fact that you need to deal with it FAST. Even with that, it has a high chance to cripple a team with its massively powerful STAB attack.
* Despite the fact that Generation 5 brought more ways to check Garchomp, it got banned. Again. Even with checks such as Air-Balloon Heatran who could otherwise come in on any attack and take it out with an Ice-type Hidden Power, if Garchomp was hiding behind a Substitute, it didn't stand a chance. In fact, the combination of Substitute and Swords Dance in a sandstorm was a menace to anyone who couldn't break the substitute and take out Garchomp before it boosted too much or set up another substitute. Unlike in Gen 4, in which Sand Veil was the straw that broke the camel's back, Sand Veil and the LuckBasedMission nature of this set were entirely the reason for Garchomp's ban this time, and once it got Rough Skin and Sand Veil itself was banned, it was allowed once again.
* [[DrillMole Excadrill.]] It has one of the highest Attack stats in the game, and one of the best STAB types, though it appears to be balanced out by its mediocre Speed. However, its ability, Sand Rush, doubles speed in Sandstorm. Yes, [[LightningBruiser DOUBLE SPEED.]] In fact, it reaches speeds so high almost nothing can outrun it, and it hits like a truck too. Oh, and the Pokémon with instant Sandstorm setup, Tyranitar and Hippowdon, are also quite the Game Breakers themselves (though Tyranitar is far more common), so Excadrill has plenty of chances to go crazy. Also, [[OhCrap it can also learn Swords Dance]]; let it get one off, and you're headed for a TotalPartyKill. Being Ground/Steel, it laughs at Thunder Wave, Stealth Rock and Toxic. Priority is pretty much the ''only'' thing that can stop it. It should come as no surprise that it got banned.
* Tornadus-T was extremely fast and had [[HealingFactor Regenerator]] and U-Turn to chip away at his checks while easily outlasting them. He was most destructive in the Rain, when he had 100% accurate STAB-boosted Hurricanes (usually boosted by a [[CastFromHitPoints Life Orb]] since Regenerator alleviated the recoil). His good [[MagicKnight mixed offenses]] also let him run Superpower to muscle past Blissey and Tyranitar (otherwise solid answers), while Knock Off let him cripple everything that switched in. Gen VI's {{Nerf}} to weather makes him much more bearable since he can't use Hurricane with the 100% accuracy all the time.
* Thundurus was not as fast, but still had a great Speed that let him beat most opposition. His Nasty Plot set could easily cut through teams with the combination of Thunder and Hidden Power Ice, Superpower let him get past Blissey/Tyranitar (just like Tornadus-T), and [[ActionInitiative Prankster]] made Thunder Wave the ultimate utility answer to opposing boosting sweepers since the priority let him fire one off before fainting. Gen VI's {{Nerf}} to weather and Hidden Power make him weaker overall, but still powerful.
* Landorus was already something of an issue in BW with a Sand Force set that was already considered powerful, but the release of Sheer Force via ''Black 2 and White 2''[='=]s Dream Radar was what pushed him over the edge. With a Life Orb he would have the equivalent of 228 Special Attack with no recoil thanks to [[LoopholeAbuse a programming quirk having Sheer Force negate it]], plus he could easily lure out his checks and counters only to use U-turn and trap them with Tyranitar's Pursuit. Unlike Thundurus, Gen 6 did not make him any less powerful[[note]]in fact, the buff to Knock Off alone made him even more so[[/note]], and he became Uber for a second time.
* Genesect got KickedUpstairs into Ubers quickly after its debut. With high Speed, Attack and Special Attack, respectable defenses, and an automatic 50% boost to either Attack or Special Attack when it switched in (depending on whether the foe's Defense or Special Defense was lower), it was the most widely used Pokemon in OU during its heyday. Genesect's standard builds got at ''least'' neutral coverage on all of standard OU and Ubers, so there was no such thing as a surefire counter to it.[[note]]The only Pokemon in the whole game that resisted Genesect's standard movesets, Rotom-Heat, lacked the defenses to wall Genesect or the offenses to do much of anything else. It was also Stealth Rock weak in a metagame, where Rapid Spin was not easy.[[/note]] Another thing that adds to the trouble of dealing with Genesect is its access to U-turn, which allows it to escape from a potential threat to it or a counter to something that deals with the threat, and Download allows it to hit hard with U-turn even without investing in attack, thanks to STAB, Download, and attacking stats[[note]]it has 120 base Attack and Special Attack, but its physical movepool is not as good as its special one, so purely physical Genesect sets are uncommon[[/note]]. Heatran, which would other wise be a nearly flawless counter to Genesect, risks being smacked by U-turn, possibly losing its Air Balloon, and Genesect switching out to, say, Dugtrio, who proceeds to destroy it.
* White Kyurem is a monster when allowed to attack. A base Special attack of '''170''' means that depending on the set, Kyurem-W can obliterate virtually anything with the right move. Between Draco Meteor and Ice Beam, Kyurem-W can take down many defensive threats, say, Lugia, Dialga and Kyogre. It learns Fusion Flare, giving it some much needed coverage against Steels, making its life easier in case it encounters the likes of Ferrothorn, Scizor, Forretress, and Bisharp. It gets better; give Kyurem-W a Choice Specs (boosted Special Attack in exchange for being locked into 1 move), and most defensive threats fall to a single attack. Its only setback is its unfortunate secondary typing, making it vulnerable to all entry hazards, Fighting and Steel type moves, and its relatively awkward speed. Still, however, it's a massive threat, more so than it's counterpart Black Kyurem, who has a movepool it can't easily abuse as well as its white counterpart.
* Another Generation V Game Breaker banned by Smogon is the Moody ability, which causes one stat to be sharply raised (essentially a free Acupressure boost) while another drops one stage every turn. Despite appearing on otherwise overlooked Pokémon such as [[LethalJokeCharacter Bibarel]], a few turns of stalling can result in an unstoppable, NighInvulnerable Pokémon capable of demolishing an entire opposing team, especially considering one of the stats that can be boosted is ''Evasion''. To quote Smogon:
-->''Bidoof nearly had to be banned because of this ability. '''[[ComMons Bidoof]]'''.''

[[AC:Generation VI:]]
* VideoGame/PokemonXAndY has the cover legendary Xerneas, which is already being looked as on par with Kyogre and Mewtwo in power. Its signature move, Geomancy, essentially gives two Quiver Dance boosts[[note]]increases to Special Attack, Special Defence and Speed[[/note]] after the end of the turn after which you use it. Combined with its bulk and its Fairy-type (a fantastic typing in Ubers, both defensively and offensively), you have a frighteningly powerful set-up sweeper that is hard to take down. For even more [[CurbStompBattle curb-stompy]] goodness, you can give it a Power Herb to make the set-up instantaneous! There are downsides to using Xerneas, however; Power Herb only works once, meaning that Roar and Whirlwind will absolutely cripple it, and it is also absolutely helpless against a good Lugia (''especially'' if said Lugia has Multiscale). However, aside from that, a Xerneas user who times their setup just right may as well say "gg ez" on the spot right before they rip through the enemy team.
* Yveltal is looking just as nasty. It may not have the "oh shit" factor of Xerneas, but it more than makes up for it with incredible versatility, having the strongest STAB Sucker Punches and Dark Pulses in the game, as well as a very effective SecretArt that acts as an incredibly powerful drain and allows Yveltal to last for an incredible length of time without putting any EVs into bulk, and its ability to run physical and special sets equally well makes every encounter with it a gamble. Guess right, and you might have a fighting chance. Guess wrong, and it'll demolish you.
* Mega Blaziken receives sizeable stat boosts in offence and speed, though it is slightly weaker in sheer damage output than a Life Orb Blaziken. A much bigger change is that, thanks to changes in breeding mechanics, Speed Boost Blaziken now has access to Baton Pass. This not only allows it to pass both Swords Dance and Speed Boost at once, it is much harder to counter as Blaziken can very well escape to a counter-counter ''with all of Blaziken's boosts''. It says something that high-level battlers in Website/{{Smogon}} were so terrified of it that they basically quick-banned it without a vote in the early XY metagame, making Blaziken Uber for the second generation in a row.
* Mega Gengar is a doozy. Speed and Special Attack on par with Mewtwo would be bad enough were it not for ''[[YouWillNotEvadeMe Shadow Tag]]'' -- the ability that got Wobbuffet banned ages ago. A smart player can pretty much 100% guaranteed clear off anything that hinders a sweep by another Pokémon like Salamence, allowing that other Pokémon to sweep with impunity. Why? [[ConfusionFu Its movepool is AMAZING]], and can be tailored to faint just about anything. Need Blissey or Chansey dead? Taunt and Perish Song wreck them. Skarmory too much trouble? Thunderbolt takes care of it. You afraid of Garchomp or Dragonite revenge killing one of your sweepers later in the game? Hidden Power Ice or Icy Wind hits them for 4x effectiveness. [[YouHaveOutlivedYourUsefulness When Mega Gengar's finished its job]], it can just then [[TakingYouWithMe Destiny Bond on whatever comes in trying to revenge kill and take them out too]]. [[http://www.smogon.com/forums/threads/xy-ou-ban-of-gengarite.3494085/ Eventually, the Gengarite was banned from Smogon OU.]] Ubers did not diminish Mega Gengar's sheer abusiveness, either, as nothing there had any tools to deal with its shenanigans either and it continued to be wildly abusive in that tier for the same reasons; it actually got so bad that Smogon suspect-tested it for banning from Ubers, which, if successful, would have completely outlawed it altogether. It failed and Mega Gengar got to stay, but given how hands-off Smogon tends to be with Ubers to begin with (as Ubers is a "just for fun" tier), you have to be really egregious to get them to even fathom completely banning you. [[OhCrap (Enter Mega Rayquaza...)]]
* Special Mention goes to Mega Mewtwo Y AND Mega Mewtwo X. Mewtwo was already incredibly powerful on its own (see Generation I), but both versions of Mega Mewtwo have a BST of 780, which is 60 points higher than ''Arceus''. It doesn't help the Base Special Attack (for Mewtwo Y) and Physical Attack (for Mewtwo X) are now the highest of all Pokémon, at a whopping 194 and 190 respectively. [[PurposelyOverpowered Looks like the claims of him being the world's strongest Pokémon have finally come full circle now.]]
* Mega Kangaskhan's signature ability, Parental Bond, makes you use the same attack ''twice in the same turn'' -- while the second attack (of the child) is half as powerful, it still amounts to a free Choice Band boost with Substitute-breaking powers on top. What really makes her terrifying are the many potential {{Combo}}s you could exploit with this ability: just for two examples, Power-Up Punch, a Fighting-type attack that raises Attack, effectively gives a Swords Dance boost while attacking, while Body Slam, obtainable from Generation III, has a ''51%'' chance[[note]]The chance of a secondary effect at least once in the two hits is 1-(1-p)^2; this comes out to 0.51 for Body Slam's p=0.3.[[/note]] of paralysing the opponent. Her movepool is expansive enough that she can beat most of her "counters" with the right move. She also has a first-strike move and more bulk than what you'd normally think of as bulky, like ''Celebi''. It really says something, [[WordOfGod when Game Freak themselves have said that]] [[MyGodWhatHaveIDone she might be a little too powerful]].
* Mega Lucario has been compared to [[LightningBruiser a Choice Band Terrakion with a Choice Specs Keldeo strapped to its back for special attack and Starmie for speed]]. This is because of its sizeable boost to ''all'' offensive stats (including speed, which is now faster than things you'd normally think of as fast, like Latios) along with the Adaptability ability, which turns the 1.5x STAB bonus into ''double'' damage. Combine this with the fact that it has ways to boost both physical and special attack, and you have something, that will raze entire teams with no support at all. To put this in perspective, a +2 Adaptability Close Combat has a chance of OHKO'ing [[StoneWall Hippowdon and Skarmory]], and a +2 Aura Sphere 2HKO's Chansey and Blissey ''with Special Attack'', something only Kyogre could before boast. And as the icing on the broken cake, it has ''three'' forms of [[ActionInitiative priority]], all with effective 80 base power.
* Aegislash. This sword is able to go on high offense and defense simultaneously due to its Stance Change ability, which switches the highest of those respective stats. This effectively gives it 720 BST, the same stat total as '''Arceus''', and also brings in several mindgames ''simply by being on the field'', where one false prediction means the loss of a Pokémon and possibly the battle. It can deal heavy damage with 150/150 offenses, and [[ConfusionFu can run multiple sets]] where some can cripple its checks and counters (Mandibuzz and Hippowdon get crippled by [=SubToxic=] for example). Being a Steel/Ghost type, it also has many resistances, making Fighting-types and Fairy-types near-useless against it. In short, its mere presence was massively centralising and prevented many other Pokémon from performing their fullest in OU, and thus it was eventually sent to Ubers.
* Mega Mawile. It has the highest attack stat in the game thanks to Huge Power, the best defensive typing in Fairy/Steel with 2 immunities and ''9 resistances'', solid bulk to go along with the typing, powerful priority in Sucker Punch, and one of the most spammable attacks in Play Rough. It had 2 main sets (Swords Dance and [=SubPunch=]) that could screw over its very few checks and counters if you guessed wrong and the only way to reliably deal with it was to let something get KO'd before sending in the check... which could faint anyway to a boosted Sucker Punch or couldn't do anything of significance due to Substitute. Its horrible Speed is just about the only thing working against it, but it has so much going for it that the Speed is little more than an occasional hindrance that seldom affects it in any meaningful way.
* Mega Salamence is a reincarnation of Gen 4 Garchomp, except worse. Possessed of all the things that made Garchomp so abusive, Mega Salamence takes all of that into even greater levels. It has even more Attack and Speed and as much physical bulk as ''[[StoneWall Skarmory]]'', and adds in enough Special Attack to allow it to viably run Special and mixed sets, making dealing with it a guessing game that you cannot afford to lose. Its Aerilate ability allows it to hit like a .50cal round with Thrash[[labelnote:*]]which is a win-button much like Gen 5 Outrage, except ''with the 30% boost from Aerilate to that''[[/labelnote]], Double-Edge, Return/Frustration, and Hyper Voice. It still does have a 4x weakness to Ice and a Stealth Rock weakness, but those are nowhere near enough to curb its general ridiculousness, especially seeing that it can reliably ''recover'' all the residual damage with Roost. It later became the first Pokemon to ever get banned from the otherwise less restrictive Smogon Doubles tier for similar reasons; for perspective, Doubles still allows things like Mega Kangaskhan. Even in the Ubers metagame, it's one of the single most horrifying offensive threats, on par with such powers beyond comprehension like Xerneas and Primal Groudon.
* Greninja began life in the Pokemon X and Y OU metagame as a master of ConfusionFu thanks to its Protean hidden ability allowing it to always hit Pokemon for STAB (and oftentimes super effective) hits, but it wasn't until UpdatedRerelease ''Omega Ruby and Alpha Sapphire'' gave it Gunk Shot and Low Kick as Move Tutor moves that it became truly terrifying. Previously consistent checks in Fairy-types became major crapshots since Gunk Shot could one-shot them with very little investment, Chansey had to stay extremely healthy for the entire match unless it wanted to get beaten by Low Kick, and people were forced to sack their Mons just to scout for Greninja's moves or get in their obvious revenge killer (which almost always had to be a obvious Scarfer). Its consistency and versatility eventually got it banned to Ubers, making it the second starter to be sent there.
* Both Primal Groudon and Primal Kyogre take the already extreme game breaker potential of their normal form and take this up to eleven with their Primal formes. Just like any Mega Evolution, they give 100 extra base stats to the Pokémon, giving them a whopping ''770'' base stats out rivaled only by Mega Mewtwo X and Y and the below-mentioned Mega Rayquaza. What really takes them to new heights are their new abilities, Desolate Land and Primordial Sea. Not only do they bring back the dreaded permanent weather that was fixed in Gen VI after plaguing Gen V (Though thankfully it goes away after they switch out), but they nullify entire types of moves (Water for Desolate Land and Fire for Primordial Sea) until they are switched out.
** Primal Groudon also picks up a secondary Fire typing: Between this new typing and a stat boost, Fire-type moves on Groudon go from only usable to devastating[[labelnote:*]]Groudon's Attack is much higher than its Special Attack; in Generations IV and V this meant running either the base 75 power Fire Punch to use the high Attack or the higher (120) base power but special Fire Blast[[/labelnote]]. The added Fire doesn't really have any downsides either, since Desolate Land nullifies water attacks, one of Primal Groudon's only weaknesses, whereas Kyogre picks up an immunity to a type it already resisted. Granted, Primordial Sea ''does'' have significant tactical value in Double Battles with Pokémon who have 4x Fire weaknesses, but outside of that, it is surprisingly underwhelming.
* Rayquaza itself was already a terrifying prospect, but '''Mega Rayquaza''' easily tops every entry above this one, up to and including RBY Mewtwo. It has a BST of 780[[labelnote:*]]same as the Mega Mewtwo duo[[/labelnote]]: both its Attack stats are at a whopping 180 and it has buffed up Speed and Defense stats. It became the most powerful Pokémon because of one detail: '''it does not need a Mega Stone to evolve.''' It only needs to know the move Dragon Ascent, a Flying-type 120 base power move with 100% accuracy. This means you can give Mega Rayquaza a Life Orb or Choice Band/Specs to skyrocket its already formidable power. [[ButWaitTheresMore But that is not the end of it.]] Mega Rayquaza also has the ability Delta Stream, which negates all weather effects (including Primordial Sea and Desolate Land) and makes moves that would be super-effective against Flying types neutral -- meaning Ice-type moves only do 2x damage (it would normally do 4x due to Ice being strong against both of Rayquaza's types) and its Rock-type weakness is erased. Mega Rayquaza is, in every sense of the word, [[PhysicalGod a God]] -- the text for activating its Mega Evolution even has you [[GodsNeedPrayerBadly praying to it]] instead of using a Mega Stone. It is so ridiculously overpowered that Website/{{Smogon}} had to convert Ubers[[labelnote:*]]known as the banlist for broken Pokémon for the longest time, and not "really" a tier[[/labelnote]] to a standard tier[[labelnote:*]]unofficially it's still a ban list first has they still need a place to put stuff banned from OU[[/labelnote]] and a new banned tier known as '''[[UpToEleven Anything Goes]]''' had to be created just to house it, banning Mega Rayquaza from Ubers. Anything Goes is ExactlyWhatItSaysOnTheTin -- all bans (like evasion, Moody, or [=SwagPlay=]) are lifted and the only clause in effect is the Endless Battle Clause. Mega Rayquaza has proven to be so broken that the ''only'' way to balance it was to throw it in a shamelessly unbalanced and uncompetitive tier.
* Baton Pass teams proved to be bothersome enough that a Smogon clause that only allows one Pokémon at most to have Baton Pass per team was eventually put in place to stop them along with Speed and other stat boosts being mutually exclusive to each other or else Baton Pass fails. Baton Pass teams revolve around the usage of multiple Pokémon with {{status buff}}s and Baton Pass to pass those buffs on to others, who continue to chain buffs and Baton Pass until it reaches something that can sweep the entire enemy team on their own. Even a JokeCharacter or unevolved Pokémon could go on a 6-0 rampage by itself, and if an already powerful Pokémon was the sweeper of choice, victory was guaranteed for the Baton Pass team. The only way to stop a Baton Pass team was to use something that could shut down the chain, remove the buffs, or somehow get lucky enough to stop the sweeper, which could severely limit team and move options.
* Shadow Tag is an ability that prevents the opponent from switching out other than any Pokémon that has the ability Shadow Tag from Generation 4 onward or any Ghost-Type Pokémon from Generation 6 onward. While it made Wobbuffet and Wynaut a problem in Gen 3, this was NOT because of the 2 being powerful offensively. Give Shadow Tag to any Pokémon with great offensive stats and speed (like Mega Gengar) and you create a monster that can revenge kill almost any Pokemon in the game with little difficulty. If the Pokémon was lacking in power or speed, buff it with a Choice item. Even a relatively sub-par Pokemon like Gothitelle can become a viable Pokemon just because they have Shadow Tag. As a result, Smogon banned the ability from OU.
* Hoopa-Unbound is a monstrously offensive powerhouse overall and one of the games's best wallbreakers due to its 160 Attack and 170 Special Attack coupled with its equally amazing movepool. Dark/Psychic is also pretty good offensively and allows it to break down some of the most common types in OU such as Psychic, Fighting, and Ghost. The Choice Specs are really what broke Hoopa-U, as there are a limited array of specially defensive Pokémon that can repeatedly switch into STAB Dark Pulse, Psychic, and Psyshock coming off of 658 to 723 Special Attack while also being potentially worn down by hazards. Its high Attack also means it can run Choice Band or mixed movesets nearly as well to stop threats like Scizor with Fire Punch, Tyranitar with Drain Punch, and Fairy-types with Gunk Shot. Smogon banned Hoopa-U from OU due to the massive unpredictability anyone running Hoopa-U is allowed.