Game Breaker / Smogon

Game Breakers within the competitive Smogon metagame that drastically influences the metagame to the point that they are sent to the realm of Ubers. A few of them even wind up being banished to the realm of Anything Goes.
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    Generation I 

    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 Pokémon 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 Pokémon 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 many sets it can run well, making dealing with it one hell of a gamble. Gen V also gave it Regenerator as a Hidden Ability, allowing it to annihilate things with 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 (and base 110 Speed means it's faster than a lot of other Pokémon, especially most of its peers). 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, 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, and Heal Bell, meaning it's incredibly hard to cause it to faint. One would think having 7 weaknesses 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 on Ghost-type Pokemon, and Poison was weak to Psychic. Fire- and Dark-type attacks were rare too (only used by Houndoom, and Celebi could learn Baton Pass to prevent Houndoom from Pursuit-trapping it), and it could easily survive an Ice Beam from most Pokémon. 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.

    Generation III 
  • Ruby and Sapphire gave Wobbuffet the Shadow Tag ability, which 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 Pokémon 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 itemnote , 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. 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 weightnote .
  • Kyogre gets a special mention; its Drizzle automatically summons rain as soon as Kyogre is sent out to the field which boosts the power of Water-type move by 50%, with STAB to boot. Not to mention that a Drizzle-summoned rain lasted permanently (until Generation VI changed it to last just 5-8 turns) unless there's another weather overriding it. In addition, Kyogre has access to Thunder, which has 100% Accuracy during rain, and Ice Beam for dealing Dragon-types and Grass-type. Considering that its Special Attack is a massive 150 with considerably better bulk to compensate, you can give it a Choice Specs to boost its special attack 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. One of the biggest appeals for Kyogre has to be Water Spout, a Water-type move that has a whopping 150 power if Kyogre has full HP, combine that STAB and Drizzle, it will be devastating to anyone unless they resist Water-type or they act first before Kyogre does.
  • Groudon is just as devasting, with a massively high 150 Attack with a very impressive 140 Defense, it can perform either offensive or defensive very well as Groudon packs fantastic supporting moves at its disposal such as Swords Dance, Rock Polish, Thunder Wave, Stealth Rock, and Roar. While Groudon doesn't gain STAB from Fire-type as it's a pure Ground-type, Drought is fantastic as it boosts the power of Fire-type move, thus pairing well with Fire Punch, Fire Blast and Overheat, and weakens Water-type moves, which Groudon just so happens to be weak to, leaving Groudon with just Ice and Grass-type attacks as its weaknesses in harsh sunlight.
  • Rayquaza. A Dragon/Flying-type 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 and Dragon Dance, it's going to send anyone into a world of pain if Rayquaza managed to set up. Rayquaza also has Extreme Speed at its disposal, striking first before the opponent could use their own priority move. Rayquaza also packs devastating moves such as Outrage, Draco Meteor, Earthquake, Overheat, Fire Blast, V-create and Dragon Ascent.
  • Deoxys has 4 forms, and all of them are Game Breakers on their own way:
    • The Attack form is the definition of Glass Cannon, 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 130 Speed. 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 Deoxys could hold 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-Dnote , and it could not be Taunted easily, as it could hold a Mental Herb or use Magic Coat to prevent Taunt. The fact that is 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.

    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 Pokémon 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 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 itemsnote . By the end of Gen IV, Garchomp, Salamence, Latios, and Latias were all banned 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. And 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 be one of the most powerful non-legendary Pokémon ever created. It possesses an excellent Attack, a fantastic type combination note , very good Speed, and having good bulk. The flagship Garchomp set contained the Yache Berry, which cut the effectiveness of Ice-type attacks, Garchomp's major weakness besides Dragon-type. 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 abilitynote  meant that with just Tyranitar in your team, attacks hit Garchomp a maximum of 72% — which Garchomp could happily abuse with Substitute until it dodges 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 has 100 Speed whereas most legendary Pokemon typically has 90, 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 Stone Wall capable of walling 90% of the game along with preventing the use of Rapid Spin, while the other one is a Mighty Glacier (10 Speed points short of being a Lightning Bruiser) who manages to be this despite the fact that it's unable to hold an item to boost its average offensive stats (it helps that the item it has to hold to use this form also boosts the power of its STAB moves by 20%).
  • 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 Lightning Bruiser, 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 it up, and then pull off a sweep with absurdly powerful Scald or Surf 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 has 120 base stat in everything, a move-pool only rivaled by Mew and 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. Notable examples include Arceus-Normal as it gains STAB from Extreme Speed, Arceus-Ground for being capable of performing either as a physical attacker or a special attacker excellently.
  • 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 Secret Art 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.
  • Dark Void, as a move, was also what caused Smeargle to be among the most feared Pokémon at VGCs. Smeargle can learn almost any move in the game through a unique mechanic, and Dark Void is not exempt. As Darkrai is banned from tournaments, Smeargle using Dark Void was the next best thing. It says volumes about how overpowered this move is that Smeargle has the low stats of Com Mons but became overcentralizing simply by being able to use Dark Void. The move was Nerfed massively to the point of being utterly useless in Generation VII, though, with its accuracy reduced to 50% (which is worse than Sing) and only being allowed to work if used by Darkrai or something that transforms into Darkrai (who now has absolutely no reason to use it outside Doubles — it'd be better off using Hypnosis).
  • Shaymin Sky forme is a Togekiss on steroids. Its Signature Move, Seed Flare, has a 40% chance of harshly reducing Special Defense. It wouldn't be too bad on its own, except its Ability happens to be Serene Grace, which doubles that chance. This, combined with its blistering Speed, means that nothing can switch in on it unless they're lucky enough not to get their Sp. Defense lowered. And then there's Air Slash, which also has its 30% chance of flinching doubled plus Shaymin-S is ridiculous fast. Shaymin-S proved to be such a bother that the vote to ban it to Ubers was a unanimous vote.

    Generation V 
  • Reshiram, the Cover Legendary for Pokémon Black, benefits from near unresisted STAB (due to Turboblaze, Mold Breaker with a fancy name), 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 Smogon is Blaziken, the first starter to make it to that tier. Its hidden 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 High 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 Luck-Based Mission 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.
  • 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. In fact, it reaches speeds so high almost nothing can outrun it, and it hits like a truck. Pairing with Sand Stream Pokemon like Tyranitar and Hippowdon make activating Sand Rush fairly easy. Also, it can also learn Swords Dance; let it get one off, and you're headed for a Total Party Kill. 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 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 Life Orb since Regenerator alleviated the recoil). His good 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 oppositions. 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 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 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 powerfulnote , and he became Uber for a second time.
  • Genesect got banned to 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  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 statsnote . 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, like, 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 into 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 its 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 Bibarel, a few turns of stalling can result in an unstoppable, Nigh Invulnerable 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. Bidoof.

    Generation VI 
  • Pokémon X and Y has the cover legendary Xerneas. Its signature move, Geomancy, essentially gives two Quiver Dance boostsnote  after the end of the turn after which Xerneas used it, which can be easily patched with Power Herb to make the boost from Geomancy occur in one turn. Combined with its all-rounded stats, being Fairy-type (a fantastic typing in Ubers, both defensively and offensively), and having the Fairy Aura ability to boost its Fairy-type attacks, it's pretty difficult to stop Xerneas from tearing teams apart outside from a few reliable checks and counters. While Choice Specs and Life Orb Xerneas users are less potentially devastating but ultimately just as much of a threat due to their non-binary gameplan.
  • Yveltal, while not as flashy as Xerneas or capable of slaughtering an entire team after just one move, is still a massive threat for a variety of reasons. First off, Dark/Flying is a great type combo made even better by its ability, which gives it horrifically powerful Dark Pulses that hit like nukes. Secondly, it is one of the single best Life Orb users in the game thanks to Oblivion Wing, which is an extremely powerful draining move that is further boosted by STAB, allowing it to essentially negate the Life Orb HP cost. Oblivion Wing coupled with Roost and Foul Play (which also gets boosted by Dark Aura) and its solid natural bulk also makes it an effective tank, and access to the strongest priority move in the game with a Dark Aura-boosted Sucker Punch is yet another plus. Its awkward Speed and middling defensive typing are hurdles, but overall, Yveltal is a massive threat that every Ubers team should plan for.
  • 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 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. For starters, it gains the Shadow Tag ability and its Sp.Attack and Speed stats are incredible. 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 thanks to its amazing movepool, and can be tailored to defeat just about anything. Taunt and Perish Song can easily wreck Chansey and Blissey. Hidden Power Ice or Icy Wind hits Garchomp and Landorus for 4x effectiveness. When Mega Gengar's finished its job, it can just then Destiny Bond on whatever comes in trying to revenge kill and take them out too. 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 Shadow Tag for banning it 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. (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 that 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. Looks like the claims of it being the world's strongest Pokémon have finally come full circle now.
  • Mega Kangaskhan is considered to be a terrifying juggernaut for her Parental Bond ability, which allows Mega Kangaskhan to 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 Combos could be exploited 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% chancenote  of paralyzing 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 when Game Freak themselves have said that Mega Kangaskhan might be a little too powerful. Eventually, Parental Bond was nerfed (the second hit deals 1/4 damage compared to the first hit) in Generation VII, but Kangaskhanite is still banned in OU.
  • Mega Lucario has been compared to 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 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 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 whenever an offensive/defensive move is used respectively. 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. Its Shield forme is absurdly bulky with 150 in both defenses, its Blade Forme can deal surprisingly heavy damage with 150/150 offenses, and it can run numerous 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. Not to mention that King's Shield, its signature move, acts as a non-status-blocking Protect while also harshly lowering its opponent's Attack if they make contact with it. In short, its mere presence was massively centralizing 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 (except Sand Veil, which it doesn't need), Mega Salamence takes all of that into even greater levels. It has even more Attack and Speed and as much physical bulk as 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, 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 Pokémon to ever get banned from the otherwise less restrictive Generation VI Doubles OU for similar reasons with one major exception, it typically paired with Jirachi as it can redirect moves with Follow Me; for perspective, at the time, Doubles allowed things like Mega Kangaskhannote  and Genesect. 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 Confusion Fu thanks to its Protean hidden ability allowing it to always hit Pokémon for STAB (and oftentimes super effective) hits, but it wasn't until Updated Re-release 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 outrivaled only by Mega Mewtwo X and Y and 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. The added Fire doesn't really have any downsides either, since Desolate Land nullifies water attacks, one of Primal Groudon's only weaknessesnote , whereas Kyogre picks up an immunity to a type it already resisted. Granted, Primordial Sea does have significant tactical value in Doubles Battles with Pokémon that are weak to Fire-type, as well as serving to give it bonuses like 100%-accurate Thunders and large boosts to its already-devastating water attacks like Origin Pulse (which will now do so much damage that its liable to One-Hit Kill things that resist it). What's particularly absurd about the Primal versions of Groudon and Kyogre is that they don't technically count as Mega Evolutions. Whereas other Mega Evolutions can only be used one per team, necessitating hard choices for who you'll give the Mega Stone to, Groudon and Kyogre can be stacked. There's nothing keeping a player from using Primal Groudon, Primal Kyogre, and Mega Rayquaza all in the same match.
  • Rayquaza itself was already a terrifying prospect, but Mega Rayquaza easily tops nearly everything. It has a BST of 780: 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 Mega Evolve. It only needs to know the move Dragon Ascent, a powerful Flying-type attack with 100% accuracy. Meaning that Mega Rayquaza can hold any item to either increase its survivability or skyrocket its already formidable power. But that is not the end of it. Mega Rayquaza also has the ability Delta Stream, which overrides other weathers (including Primordial Sea and Desolate Land) and weakens moves that would be super-effective against Flying-types — meaning Ice-type moves only do 2x damage rather than the usual x4 damage and its Rock-type weakness is erased; it also becomes resistant to Electric-type moves. Mega Rayquaza is so immensely powerful that Smogon had to convert Ubers to a standard tier and a new tier called Anything Goes had to be created to house it, banning Mega Rayquaza from Ubers. Anything Goes is Exactly What It Says on the Tin — 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 format.
  • 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 buffs 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 Joke Character 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 Pokémon like Gothitelle can become a viable Pokémon 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 game'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.

    Generation VII Singles 
  • Power Construct Zygarde. At 50% or less of its health, Zygarde with this ability transforms into its Complete Forme. Zygarde-Complete has incredible bulk on both sides of the spectrum due to the drastic increase in base HP. Sporting a massive 216 base HP alongside 121 Defense and 95 Special Defense, it can absorb even strong Ice-type attacks (which do 4x damage to it) with impunity, while using Coil to boost itself, put down massive-HP Substitutes which would trigger the forme pretty quickly, Rest to recover all of its status and health with Sleep Talk to boost itself, and it sports Thousand Arrows, a powerful Ground-type move that hits Flying types — coupled with the attack boost from Coil, and it will hurt a lot. Pretty much only Unaware Pokémon could stand a chance against a boosted Zygarde-C, and it would shrug off almost everything else while destroying them with impunity. It was just too good in OU, and the ability Power Construct was banned to Ubers within the first few days of play. It was later banned in Doubles OU as well for the exact same reason, only with Dragon Dance.
  • Pheromosa. With its blazing speed that only a few Pokémon can actually outspeed it without using priority attacks (even then, not many priority attacks can OHKO it) and both its offensive stats being amazing. And if those aren't enough, being an Ultra Beast, Pheromosa has Beast Boost as its ability, which increases its highest stat every time it defeats a Pokémon, allowing Pheromosa to become either faster or hit harder depending on which stat it specialized in. In addition to its usual Bug-type and Fighting-type moves, Pheromosa has Ice Beam to deal with Ground-type, Flying and Dragon-type Pokémon, and Poison Jab to deal with Fairy-type Pokémon. Even worse, Pheromosa also has access to Quiver Dance, which, while it might seem unappealing at first due to Pheromosa's fraility, allowed it to become a terrifying special sweeper that could blow past some of its usual checks, especially when combined with Z-moves. While Pheromosa does have flaws, such as being incredibly frail and unable to do that much with bulky Ghost-type, those aren't enough to stop its wrath, and Pheromosa was eventually banned from OU.
  • Mega Metagross narrowly escaped from the banhammer treatment in Generation VI due to regular Metagross's speed and predictability, but Generation VII saw it nowhere near as lucky. Thanks to a mechanic change allowing their boosted speed on their opening turn upon Mega Evolving and the terrain abilities, Mega Metagross became a dangerously fast and bulky sweeper that could blaze through half of the Pokémon in a team. While it did have weaknesses, many found it far too centralizing and it was swiftly banned.
  • Baton Pass was a move that allowed to pass boosts to another Pokémon in your team. With Generation VII's advent, two very good recipents came around in the form of Necrozma and Magearna. Necrozma's ability to tank hits and Magearna's typing and stats were the straw that broke the camel's neck. There wasn't too much counterplay to deal with them, considering that Baton Pass teams would often have a Dugtrio to deal with the recipent's threats. Even after the restriction that came around Gen VI to ban passing Speed with other stats, no matter if the Baton Passer would pass either Speed or other stats, after the chain, it was more than enough to deal with the opposition with little support. It was no less abusive in Ubers, thanks to the Z-move Extreme Evoboost (exclusive to Eevee) which doubles every stat, allowing Espeon's Stored Power and Krookodile's Power Trip to become instant unstoppable nukes. The chaos that this ensured was too much to ignore, therefore, the move itself eventually got banned in Generation VII, ultimately becoming the first thing in Gen VII banished to Anything Goes.
  • Marshadow. An utter monster from the onset, it packs arguably the best offensive STAB in the game (hitting seven types super-effectively and able to score neutral on literally anything else, something that was unheard of in STAB combos), a very high 125 Speed, having Technician as its ability to boost the power of Shadow Sneak and Hidden Power, a fantastic coverage thanks to the aforementioned Hidden Power boost and deceptively high bulk of 90/80/80. What really put it into this territory though is its Signature Move Spectral Thief, a powerful STAB move that steals all stat boosts. Using this, setting up against and revenge killing Marshadow becomes nigh-on impossible, since any attempt to do so would result in Marshadow using Spectral Thief to steal such set-up bar from Normal-type, rendering the time spent worthless and making it even more impossible to kill. What's more, any Pokémon that could wall it would be instantly KO'ed by its extremely powerful Z-Move. People were begging for it to be banished to Ubers the moment it was revealed, and, sure enough, it was sent there a mere two days after it was officially released. As for Doubles OU, Marshadow didn't get banned from its first suspect test since Spectral Thief isn't considered too problematic here. As time goes on, it becomes apparent that the unresisted coverage part is an issue and it becomes pretty centralizing, leading to a second suspect test where Marshadow gets banned.
  • While Dugtrio always had a reputation thanks to Arena Trap, Gen VII applied a number of buffs that turned it into an utter monster. Between a significant buff to its Attack, the addition of Z-Moves and the general Nerf to priority, Dugtrio transformed into a monster that could KO any staller it laid eyes on and, thanks to its high speed and good attack, still function on a team after fulfilling its purpose. While it was hurt somewhat by its terrible bulk that ensured it would faint in one hit unless it holds a Focus Sash, it still became one of the most despised in OU, and Arena Trap was eventually banned.
  • From the USUM newcomers, there was Naganadel. Being Poison/Dragon gave it a really good defensive typing, a formidable 121 speed, and a really good 127 special attack. Naganadel also has Nasty Plot to boost its already good Special Attack, Beast Boost as its ability to increase its Speed with every KO, and can learn Flamethrower/Fire Blast for perfect type coverage. It usually had just enough HP to get off a Nasty Plot, and even with a single boost and a Dragonium-Z for a one-time nuke, Naganadel could run amok through almost the entire metagame after its first KO, with Ash-Greninja being one of the few things that could outrun it after only one Beast Boost. Players were forced to run Pokémon like Tyranitar and Heatran, or even unconventional checks like Assault Vest Magearna, in an attempt to stop its rampage, and even that wasn't a guarantee due to the huge amount of damage that a +2 Devastating Drake off of Draco Meteor (195 Power) could do. Naganadel's presence warped the entire metagame so much in a small amount of time since its introduction, therefore, it became the first Pokémon to get banned from the USUM metagame.
  • Normal Necrozma isn't considered to be too much of a big deal, but both Dusk Mane and Dawn Wings Necrozma were instantly banned due to their stats being the same as Solgaleo and Lunala respectively, and both having Prism armor to reduce damage from super effective moves ala Filter or Solid Rock. Then there's Ultra Necrozma, with a Whopping 754 BST, out matched only by Primal Groudon, Primal Kyogre, Mega Mewtwo X and Y, and Mega Rayquaza, but with even better Stat distribution then any of them. Not only does it have a large amount of coverage moves to fight against the weaknesses of both Dragon and Psychic, it has its own Z-move, Light That Burns The Sky. It's essentially a Mega Evolved Pokémon that can use a Z Move. To top it all off, Ultra Necrozma’s new ability, Neuroforce, acts like an Expert Belt boost to all of its super effective moves, and with its massive coverage, it can and will use something super effective against its counters. And of course, it can be stacked in team with Primal Groudon, Primal Kyogre and a Mega Evolution of your choice.
  • If you decide to opt out of using Ultra Necrozma, Dusk Mane Necrozma in particular has proven itself to be one of the best Pokemon in Ubers thanks to its fantastic bulk coupled with Prism Armor that reduces the damage done by super-effective attacks with the added benefit of being unaffected by Mold Breaker and the effect of Moongeist Beam, Sunsteel Strike, and Photon Geyser. Additionally, Dusk Mane Necrozma is immune to Toxic while having a Stealth Rock resistance and it has either Moonlight or Morning Sun for recovery. As for the offensive department, Dusk Mane Necrozma has an amazing attack stat with Solganium Z for extra firepower. While it isn't very agile, it can be easily patched with the assistance of either Rock Polish or Trick Room. Finally there's also an initial unpredictability (in the opponent's view) of whether or not it'll Ultra Burst into Ultra Necrozma. To prove Dusk Mane Necrozma's worth, it can make the infamous Xerneas a run for its money.

    Generation VII Doubles 
  • Magearna is pretty solid on its own in OU, but that's a very different story in Doubles OU. If any Pokémon faints (including its partner), Soul-Heart will activate and raise its Sp.Attack stat. As there are more Pokémon on the battlefield, it’s way easier for Magearna to activate its ability. Combining that with its already nice Sp.Attack stat, nice bulk, nice coverage, excellent defensive typing and Dazzling Gleam to hit both foes without harming the partner, and it will tear almost anything apart with minimal effort. Even its speed issue can be solved by using Trick Room or Tailwind. As a result, it was quickly banned along with Power Construct in Doubles OU.
  • Extreme Evoboost wound up becoming the first Z-move to be banned by Smogon, being evicted from Doubles OU for its sheer abuse potential. The move sharply raises all of Eevee's stats (except for accuracy and evasion), which Eevee could then Baton Pass onto another Pokemon with the help of a teammate using moves like Wide Guard, Fake Out or Follow Me to keep opponents from defeating it. While basically anything with a 2x boost to speed, offenses and defenses is a Lightning Bruiser to the extreme.
  • Jirachi has been known for being the premiers Follow Me users in Doubles OU. Back in Generation VI, Jirachi was suspect tested and it wasn't banned as a result. While it doesn't change all that much in Generation VII, the Doubles OU has shifted into focusing on setting up thanks to several factors such as Snorlax and Tyranitar performing better due to most Fighting-types Pokemon phasing out as well as Mega Salamnece being unbanned, causing Jirachi benefitted too greatly from that simple metagame change. Resulting in another suspect test held for Jirachi in Generation VII and it was successfully banned with just enough votes.
  • Mega Kangaskhan is guilty of this once again, this time in the Generation VII Doubles OU instead of only Singles. With the aforementioned damage nerf of her signature ability, Parental Bond, savvy Mega Kangaskhan players instead turned to Seismic Toss. Doubled Seismic Toss enables Mega Kangaskhan to 2HKO most of the Pokémon in the game and anything that would decrease its attack doesn't cut its damage output. The transition also means players can invest more bulk to Mega Kangaskhan while Wish becomes a popular recovery option for it. The Tapu scaring off most of its counters doesn't exactly help matters either. As a result, Kangaskhanite got banned from Gen VII Doubles OU.
  • With the nerf done to the confusion status and the accuracy drop to Swagger in Generation VII, it was unbanned. Swagger has found its place in Doubles OU for giving attack boost to physical attackers. Tapu Fini has Misty Surge which prevents being confused by Swagger if they are on the ground, and Heal Pulse for increased longevity to its partner. The straw that broke the camel's back was the arrival of Marshadow as it has a Spectral Thief that steals stat boosts from the opponent while also being able to OHKO most of them with said boost. This led to the Doubles OU council banning Swagger yet again.
  • In Generation VII Doubles OU, there’s Snorlax. With most Fighting-type phased out in Generation VII, Snorlax finds itself acting as a Trick Room attacker with Curse or Belly Drum in DOU. Gaining High Horsepowernote  and buffing pinch berries to restore 50% HP while making them interact with Gluttony vastly helps its role. However, with Marshadow banned from DOU, Snorlax lost one of its best checks. This caused the rise of Belly Drum. The Belly Drum variant ended up being too overwhelming to handle, even with ways that can prevent it in one way or another. Pairing Snorlax with Gothitelle; another Pokemon that benefited from Marshadow being banned, also serves as a factor as Gothitelle can trap opponents with Shadow Tag and supports Snorlax with Heal Pulse and Trick Room. This results in Snorlax being the subject of the suspect test and it was subsequently banned from Doubles OU.

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