Game Breaker / Yu-Gi-Oh! Card Game
aka: Yu-Gi-Oh Card Game

"As a prophecy, I can tell you that you should never expect Raigeki, Harpie's Feather Duster or Yata-Garasu to ever leave that list".note 
Edo regarding the Forbidden lists.

Generally, every format has at least one deck that qualifies as Game-Breaker. The Gamebreaking deck and cards in Yu-Gi-Oh! constantly change whenever the metagame shifts, new cards are released, and the Banlist is shuffled. As a general rule of thumb, cards that are placed on the banlist were found to be too effective at the previous format.

Also, as a result of Sequel Escalation and Power Creep, some old decks that were completely unfair in their heyday would not be so great a threat nowadays, even if they're untouched by the banlist.

Below is a list of Game Breakers introduced in their respective eras.
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    General 
  • Hand control cards in general are infamous for their Game-Breaker-ness. Delinquent Duo was one of the first-ever entries on the banlist, and Confiscation and The Forceful Sentry didn't take long to follow it. Trap Dustshoot, once thought of the balanced alternative, got involved in a devastating combo with Mind Crush that put it on the banlist as well. Even Don Zaloog was considered a tournament staple for quite some time, largely for this reason. And then there's TRISHULA... To make matters worse, while destruction cards like Raigeki only get weaker with time as more revival or protection methods become available, hand control cards have only gotten stronger, between the increased importance of card advantage and replenishing a lost hand being a lot harder than replenishing a lost field.
  • Any card that switches control of monsters is a likely target: Change of Heart is banned, Brain Control was only able to come back with a severe nerf, Mind Control (which was designed to be a useless version of the above cards) is limited, Snatch Steal's time as a limited card during the January 2015 format proved the card to be a cheap topdeck card to the point that is immediately rebanned again, and Big Eye was semi-limited in the OCG despite being tricky to summon. The biggest advantage to Monster Reborn (which goes on and off the banlist depending on the phase of the moon) is that it's one of the only revival cards that has the option of stealing opponent's monsters.
  • Many stun/lock cards, particularly Time Seal, skipping the opponent's next draw phase, and Cold Wave, preventing setting/activating spells/traps until your next turn (see banned cards).
    • Floodgates, cards that stop certain decks from making plays entirely or certain types of cards from being used, can also fit this trope. While most of these are balanced by being good only against certain match-ups and being vulnerable to removal cards, some are so universally great against the metagame that they end up stunning almost everything, to the point of getting hit by the limited or even forbidden list. A big problem involving these cards is that the one using them can often make all the plays they need to make to establish a big obstacle to overcome, then activate the play-preventing card to make it very difficult for the opponent to retaliate, effectively buying the user a free turn at minimum. The particular ones being Imperial Order, Royal Oppression, Number 16: Shock Master, and Vanity's Emptiness (see banned cards).
  • Cards that remove the wait one turn restriction on trap cards for all trap cards inevitably become this, as it removes their intended downside (they were most frequently abused with draw power traps, but other traps could become more effective with these cards too). Temple of the Kings was banned for 4 years in the OCG before being brought to other regions instantly banned upon release and stayed such until it received an errata. And, more infamous is Makyura the Destructor, one of the most helpful cards ever created (see banned cards).
  • Most cards with a great draw power to them with little to no drawbacks to them, or has "drawbacks" that are more beneficial to the player, such as sending cards to the Graveyard in a meta-game where summoning things from the graveyard is a major part of the game. Besides giving you more cards to work with, it lets you thin the deck in hopes of getting more cards you truly need to possibly OTK your opponent. The most famous of these cards is Pot of Greed which, despite being one of the most simple cards in the game, (lets you draw two cards with no drawbacks, a fact that the various animes won't let you forget) has been on the banlist since the banlist was first made.
  • Mass summon cards often result in this, due to their ability to create One Turn Kills, loops, or nigh unkillable fields. Magical Scientist, Ultimate Offering, Dimension Fusion, and Return from the Different Dimension are banned for this. Ditto for why Rekindling and Infernity Launcher are limited. Even Soul Charge, a card designed specifically to prevent abuse in OTKs and loops, still had to be limited as well.
  • Any card that makes searching the important monsters for a good set up way too easy, or just get critical cards for your deck. Witch of the Black Forest was banned exactly for this reason and Sangan goes about as much on and off the banned list as Monster Reborn. Reinforcement of the Army is limited for similar reasons.
  • Any card that removes the threat of back row (Set spells/traps)with no cost is often this, as they can often win games all by themselves against decks that rely heavily on them. Harpie's Feather Duster, Cold Wave, Heavy Storm, and Giant Trunade were banned for this reason.
  • The ultimate example of gamebreakers in the game are First-Turn Kill (often abbreviated as FTK) decks. While most are far too inconsistent to be viable competitive decks on their own, the rare few that are often have the potential to completely dominate the metagame, to the point that a ban and/or limit on cards that make the combo possible is guaranteed to happen. This was even worse before the advent of hand trap effects such as Effect Veiler, where the metagames involving these decks were little more than coin flips to see who could FTK the other first (and even with hand traps, you still lose if you go second and lack any to use aganst it). Some of the more notorious FTKs are the old-school Empty Jar FTK, Magical Scientist FTK (See Banned cards folder for these two), Frog FTK (see 5D's), all FTKs enabled by the aforementioned Makyura the Destructor and pre-errata Temple of the Kings, and all FTKs built around Blaze Fenix, the Burning Bombardment Bird (the reason it's limited in the OCG).

     Banned Cards (TCG) 
With few exceptions, any card that winds up on the banned list (see here) is too powerful for its own good, and would heavily skew the game in a player's favour if they're used in any number. There have been cards that have been banned since the Forbidden List was first drafted, and they still haven't left after over a decadenote . Edo (a once popular webhost who ran one of the most popular Yu-Gi-Oh TCG websites), had something to say about it in his 2005 "Copaca-BAN-a!" article. To read what he said, check the quote at the very top of this page.
  • Banned Jar cards (some of the most powerful and Power Creep proof flip effects in the game):
    • Cyber Jar was an extremely powerful staple in many decks before becoming banned. When flipped, it nukes the entire field and forces both players to reveal the top 5 cards from their deck and Special Summon all Level 4 or lower monsters in face-up attack or face-down defense, with anything else being added to the hand. It served as a "get-out-of-jail-free" card, usable in any bad situation, that also gave the user a significant field and hand advantage.
      • Cyber Jar had an entire deck built around a first turn kill using cards like The Shallow Grave, Book of Taiyou, and Card Destruction to deck the opponent out before they can draw. Americans tried fixing it by restricting Book of Taiyou which worked, but since the World Championship didn't have such a restriction, it dominated the tournament leading to Cyber Jar's death.
    • Its cousin, Fiber Jar, was even worse. Got a bad hand? Close to losing? Your key monster is in graveyard and you can't recover it? Fear not! Just flip up Fiber Jar and it sends every card on both players' fields and their hands and Graveyards back into the deck while drawing 5 new cards, effectively resetting the game.
    • Morphing Jar makes both players discard their entire hand (if any) and then draw 5 cards. Due to its ability to bring a player right back into any game, abuse in Empty Jar decks, and ability to facilitate graveyard setup, the card had been limited for a long time. However, the final nail in its coffin was it and the below card's abuse with the otherwise Awesome, but Impractical Jackpot 7 by giving and triggering it on the opponent's field in the OCG, which resulted in its ban before said card was even released in the TCG.
    • Morphing Jar #2 shuffles all monsters on the field back into the deck, then makes both players excavate (reveal from the top of their deck) cards until they reveal monsters equal to the number of monsters shuffled into the main deck (making it extra painful to extra deck users), special summon any level 4 or lower monsters, and send all other excavated cards to the grave. This card was always very disruptive to One-Turn Kill attempts and is abusable in OTKs of its own, but was banned for the same reasons as the above card.
  • Banned draw power cards:
    • Pot of Greed is a classic card with a simple effect to draw 2 cards. No costs, no downsides, and no conditions, meaning that it's a free +1 that can be activated at any time by anyone who draws it. There's no reason not to play this card if it were legal.
    • Graceful Charity is easily one of the best toolbox cards the game has ever seen. It lets you draw 3 cards, and then discard 2 of your choosing (Meaning no hand advantage is lost using it). Between the insane draw power and easy graveyard set up and/or effect triggering, it's even better than Pot of Greed in many decks.
    • Card Destruction is not only extremely useful in mill decks, but also allows you to setup your graveyard effects and plays, being somewhat similar to Graceful Charity, its only difference being that using it actually takes away one card from your hand. Not that it matters; the acceleration the card provides is more than enough.
    • One of the most useful cards to be released in Japan before the first Forbidden List was instituted was Sixth Sense, which was not released in the TCG until more than a decade later. In theory, the card is a risk or reward. You declare two numbers between 1 and 6, and if your opponent rolled one of the declared numbers, you draw that many cards, otherwise you mill the number of cards that was rolled. Except that the game is now based around graveyard manipulation, so its effect is more often a win-win situation. You either draw an absurd amount of cards from your deck, putting you far ahead in card advantage that you can pretty much win the game, or you got to mill cards from your deck, potentially setting up whatever combo you need to win the game, and increase your chance to draw cards you wanted from the deck. As stated before, the card came out in Japan before the Forbidden List existed, and as soon as it was introduced, the card was Forbidden and has held that position ever since. To put it in perspective, the only other cards to have been banned for as long as banning a card has been possible are Chaos Emperor Dragon — Envoy of the End, Harpie's Feather Duster, and Yata-Garasu. It's that formidable.
    • Pot of Avarice shuffles back 5 monsters from the graveyard into the deck and then lets you draw 2 cards. Essentially a Pot of Greed that recycles your monster engine for reuse. Its only downsides by contrast are that it's slower and can make it more difficult to draw specific cards you need to overcome a certain situation. Initially Limited in September 2005, and enjoying a run through the GX and Synchro era, thanks to the increasing summoning speed and shuffling only extra deck monsters that allowing it to basically act as Pot of Greed, it was Limited again in September 2011 and finally banned in September 2013 after the card proved itself too cheap to be allowed to run free.
    • Destiny HERO - Disk Commander lets you draw 2 cards any time it's summoned from the graveyard. Yep, every revival card in the game suddenly becomes a Pot of Greed with this card (On top of it being prime discard fodder for Destiny Draw). Does anything else really need to be said about it?
    • Card of Safe Return's effect is to draw a card anytime you special summon from the graveyard. When combined with decks that are heavily based around graveyard revival, this allows you to draw a ton of cards as you make your plays.
    • Mirage of Nightmare allows you to draw cards until you have 4 in hand during your opponent's standby phase, but requires you to randomly discard the same number during your own. Even ignoring its potential for rapid graveyard setup, its downside can easily be dodged by preventing its discard effect from resolving (like destroying the card yourself at the end of the opponent's turn), allowing you to keep all the cards drawn off of it.
    • Super Rejuvenation is a quick-play spell card that allows you to draw a card for every dragon type monster discarded or tributed that turn. It saw some niche play in Exodia decks running the Blue-Eyes/White stone Card of Cosonance/Trade-In engine, which would discard these cards with their respective spells for draw power. What really broke the card to the point of banning were the Dragon Rulers (see below in the folder), a deck which thrives off of discarding dragons for effects, and allowed you to discard your hand very quickly, only to replenish it during the end phase. Not helping is the fact that it is not a once per turn, which, combined with the fact that it's a quick play, allows you to draw an insane amount of cards, since you can activate any you draw off other copies. It was common to see Dragon Ruler players activate it even if they already had a full hand. This might sound counter productive, but for Dragon Rulers, a deck where your grave is practically a second hand, it just allows you to setup your grave that much faster and keep any handy spells, traps, or hand trap effect monsters you draw ready for the next turn.
    • Chicken Game allows one card to be drawn at the cost of 1000 LP for once per turn. Such restriction can be bypassed and abused by having three copies of it as well as three copies of Pseudo Space, where six cards can be drawn by a hefty 6000 LP in total. Draw power will go Up to Eleven when used with Terraforming, Royal Magical Library, Upstart Goblin (which is currently limited in the TCG format) and Hope for Escape, where a total of eighteen cards is drawn. Such play style makes Exodia an even more Tier-Induced Scrappy solitaire deck. There is also an FTK combo involving the aforementioned cards, the Monarchs, Life Equalizer (which is currently banned in the OCG format) and Magical Explosion.
  • Banned hand control cards:
    • Delinquent Duo has you pay 1000 LP, then the opponent discards 2 cards, one randomly chosen, and the other of their own choosing. A sort of inverse Pot of Greed, this card was often devastating if used first turn, since they effectively lose 1/3 of their opening hand, with no ways to respond. Its only downsides are enabling gravyeard setup, but the card is so powerful that the risk doesn't matter.
    • Confiscation has the same 1000 LP cost and discards only one, but it lets you pick and discard the card you want, making it arguably more powerful.
    • The Forceful Sentry is the strongest of the bunch; not only you don't pay any LP, shuffling is a more powerful way of removing a threatening card on your opponent's hand as it doesn't allow them to setup their graveyard and can deal more easily with monsters.
    • Trap Dustshoot, the most "balanced" of the bunch, due to being a trap, only being able to be activated if your opponent has 4 or more cards, and can only shuffle back monsters, still was such a devastating card going first (especially when combined with Mind Crush), that it too was banned. It also didn't help that its super rare version's unusual thickness made it easy to stack.
    • The Forceful Sentry, Confiscation, and Trap Dustshoot all have an effect to look at the opponent's hand and cherry-pick a card to get rid of. But you also get the advantage of knowing what cards are in their hand, allowing you to prepare accordingly and/or use Mind Crush to further cripple their hand.
  • Banned monster stealing cards:
    • Change of Heart was among the very first cards ever banned in the game, and for good reason. Its effect is to take control of an opponent's monster until the end phase. The fact that it returns during the end phase is its only downside, which is almost always rendered moot by the fact that you're going to probably attack with it, tribute it, or use it for the summon of another monster, ensuring that they don't get the chance to use it again.
    • Snatch Steal is an equip card, meaning it can steal an opponent's monster permanently as long as it's equipped. Its only downsides are that it gives the opponent 1000 LP during each of their standby phases and the inherent equip spell downsides of being unable to target facedown monsters and losing to spell and trap destruction. It was banned for 8 years before Konami decided to bring it back in the January 2015 banlist...where it proved to be nothing more than a cheap topdeck card that can be searched or reused with Hidden Armory (which prevents normal summons during the turn it's activated, but that's irrelevant in decks that don't need to do so) resulting in it being immediately re-banned in the following format.
  • Banned Floodgates:
    • Royal Oppression allows both players to negate any and all special summons at a cost of 800 LP each time. This seems balanced until you realize that you could just swarm your field during your turn then flip this card up during the opponent's turn, not to mention that certain cards can activate their special summon effects infinitely, making attempts to stop their effects futile, and it can't be used during the damage step.
    • Number 16: Shock Master. This colorful ruler has an effect that locks out either Spells, traps or monster effects, its a Rank 4, the most supported rank/level in the game. The only attempt at balance was that it required 3 materials, but that would had been easy with -hunders, Wind-Ups and the then-upcoming Satellaknights, and Pendulums in general. And it can be protected by Number 66: Master Key Beetle. It was banned in the TCG before the ARC-V cards (including the Satellarknights) made the scene but it was still unlimited in the OCG until the January 2016 list banned it.
    • Djinn Releaser of Rituals, by far the best of the ritual supporting Djinn archetype that can also be banished from the graveyard for ritual summons, blocks Special Summoning only on the opponent's side if used for one. However as Ritual Summoning proved to be incredibly difficult and not worth the resource spent, such an effect never became a huge problem, until Nekroz (see Arc-V folder) came about and alleviated every single weaknesses that Rituals have. All of a sudden, the Djinn-lock becomes a massive headache for the duelists to deal with because they can us Nekroz Cycle in tandem with Djinn and Clausolas in order to lock the other player from Special Summoningnote . This forces many players of this format to main deck anti-Djinn cards such as Bull Blader, Book of Eclipse, and D.D Warrior Lady in order to make their plays or else they get locked forever. Due to forcing the usage of otherwise mediocre and/or outdated cards just to answer it, the card was banned.
    • Kaiser Colosseum has the effect that basically makes it so that the opponent can't summon any additional monsters if it would make it so they control more than you do if you have a monster on the field. While it saw little play back when it was released, once new summoning mechanics came into being, such as Synchro and Xyz summons (as well as Link summoning, which came after this card's ban), this card became a nightmare for many duelists to deal with. As these mechanics require multiple cards to be on the field to be used, if a player using this card can maintain a monster on the board (an easy feat in protection and/or floater based decks), many decks will be stuck being unable to get their critical plays off if they fail to get rid of Kaiser Colosseum.
    • Rounding out the unholy trinity of anti-Special Summon floodgates is Vanity's Emptiness. It's a Continuous Trap Card that completely prevents any sort of Special Summoning by both players, and because of this, it generally will be activated on the opponent's turn in response to an effect that Special Summons a monster(s), making them waste resources for absolutely nothing and more often than not making them lose a turn entirely. But it also stops the owner from Special Summoning so it's a fair exchange, right? Well, Vanity's Emptiness also sports a "downside" that causes it to destroy itself if a card is sent from its owner's deck or field to the Graveyard, which is almost embarassingly easy to exploit with something as simple as using a Spell or Trap Card. And, like Royal Oppression, you can simply do all of your Special Summoning before flipping Vanity's Emptiness and watching your opponent squirm. While the downside also makes it easier to play around than Djinn Releaser or Royal Oppression, Vanity's Emptiness still proved game-breaking enough to warrant a ban.
  • Banned Mass summoning cards:
    • Magical Scientist, which is perhaps the only card in the history of the game that is necessary to give your opponent zero chances of countering whatsoever without relying on alternative win conditions and thus effectively dethroned Yata Garusu (see above) as the most feared card in the game. On its own it was not all that bad. At best it allowed you for something that defends you very well, but once you combine it with cards such as (Pre-errata) Catapult Turtle, which allow to tribute monsters to do direct effect damage and you see how great the thing can get, especially with cards that allow you to get both on field. With Scientist being a level 1 and only needing 3 cards in the hand and 7 cards in the extra deck needed to win with it and the chance of pulling it off exponentially increasing with more support cards for it in the main deck, you can see why Konami decided to ban Magical Scientist not shortly after publication. Even after the Catapult Turtle errata, the card remains rather effective, since Xyz monsters are now a thing, and this card can swarm the field with them by itself.
    • Dimension Fusion has you pay 2000 life points, and then both players summon as many banished monsters as possible. Among other things, this was a key card in the infamous Dark Armed Return deck, which was so fast and powerful, that it became the first entire deck to be emergency banned with this being banned along with its partner in crime, (Pre-errata) Dark Magician of Chaos, which allowed for instant recycling of it.
    • Return from the Different Dimension, a trap version of the above, was limited in that same emergency banned list for similar reasons. The final nail in its coffin came when Dragon Rulers came out, and this card became an instant One Turn Kill for said deck almost any time it was used.
    • Ultimate Offering lets you pay 500 life points to normal summon a monster during your main phase or the opponent's battle phase. Yep, a card that lets you bypass one of the most basic restrictions in the game as long as you have life points to spare. This card saw all kinds of abuse in decks with heavy normal summon search power (Gadgets and Blackwings in particular) before it was banned.
  • Banned graveyard setup cards:
    • Painful Choice: While it most definitely lives up to its name, it hides what is quite possibly the most convenient graveyard setup card ever created in the game. If you use this card right, it should matter little what the opponent chooses as everything else goes to the graveyard and, unlike Future Fusion below, this card can be splashed into any deck. After using this card, you can gain tons of advantage for each card sent or simply instant setup for Soul Charge, Rekindling, or for resources to banish for special summon monsters. It's so devastating, that it was among the very first cards to ever be banned in the game.
    • Substitoad has an effect to tribute a monster to summon a Frog monster from the deck. Doesn't sound like much on its own, until you realize that it's not a once per turn effect, allowing you to send every single frog monster in your deck to the graveyard. This card, combined with Mass Driver (also banned, see the loop subsection) and Ronintoadin, enabled the infamous Frog FTK deck, which was so consistent, it won the Yu-Gi-Oh world championships in 2010. It got banned in September 2010.
      • To elaborate, the FTK used Substitoad, Mass Driver, Ronintoadin and Swap Frog along with enough Frog monsters (18-20 to counter the usage of banish removal) to wipe out the opponent's LP. Finding a way to get Ronintoadin on graveyard, and a monster other than Substitoad on field to tribute, the deck would continuously tribute Frogs until it filled the graveyard and then use Mass Driver to go for game.
    • Mind Master, which is essentially a Substitoad for psychic types, albeit with a stricter tribute cost and an 800 lifepoint cost per use (unless you use Brain Research Lab or Telekinetic Charging Cell...). Due to a much larger pool of monsters to choose from than Substitoad, there are many potential ways to (ab)use this card. But, the most infamous combo involves Caam, Serenity of Gusto, where every 1600 lifepoints spent gets you another draw using Caam's effect. And if you combine Mind Master with the aforementioned cards that remove the lifepoint costs? Congratulations, you now have an infinite draw engine.
    • Fishborg Blaster is a level 1 tuner. At first the effect may appear fair, as you need to synchro with it only using WATER monsters and need to discard a card to special summon it, limiting its usage... until you realize the existence of multiple monsters that offset the cost while being summoned and the existence of multiple engines that swarm the field with WATER monsters with little to no cost. Fishborg could lead to some crazy fields in what came to be known as Water Synchro, and was a big part of what got T.G. Hyper Librarian and Formula Synchron limited (see 5D's folder). It was banned in September 2011, being one of the few cards that went from Unlimited to outright banned. And its abusability has only increased throughout the years with the addition of the Atlanteans (see Zexal folder).
    • Lavalval Chain is a Rank 4 Xyz monster (the most supported rank in the game) with an effect to send any card from the deck to the grave. This card was abused in several FTKs and loops, resulting in its ban. Its second effect is also really useful for stacking any main deck monster, which coupled with any draw card enables a lot of combos.
  • Banned anti-backrow cards:
    • Harpie’s Feather Duster, which was on the first ban list and hasn't left since (in the TCG at least), has the effect to destroy all spell and traps the opponent controls. It’s a free back row nuke of the opponent, your own cards left untouched. As if that weren’t bad enough, this card would now be searchable off of Hysteric Sign and the far more splashable Harpie's Feather Storm if it could be used. Enough Said.
    • Heavy Storm is similar, but also does affect your own cards. So, while it can be problematic late game if you play a backrow heavy deck, it’s still just as effective as Harpie’s Feather Duster going second for any deck. When this card was legal, it pretty much mandated playing Starlight Road if you ran a backrow heavy deck, lest you lose it all to Heavy Storm.
    • Cold Wave, which prohibits both players from activating or setting spells or traps until your next turn, allowing the user to go the first two turns without needing to worry about spells or traps or go straight for the kill, barring any monster effect use. It also does not destroy, making it much harder to answer than the above cards.
    • Giant Trunade returns all spell/trap cards on the field to the hand. Like Cold Wave, this card does not destroy, limiting answers to it. But, on top of the power of clearing backrow, it also allows you to reuse continuous spells/traps for either additional plusses, and/or giving yourself a turn to play around your own floodgates, then reactivating them against the opponent before they can do the same.
  • Banned control cards:
    • Last Turn, which clears the field of all but one of your monsters, wipes the field and hands and then your opponent special summons any monster, last man standing wins. Sounds fair right? Until you realize just how many monsters have an effect that prevents special summons or the abundant ways to abuse the loopholes in the card and guarantee a win or at worst, a draw.
    • Chaos Emperor Dragon - Envoy of the End. You know a card is broken when it is explicitly banned in the anime. CED is Summoned by banishing one LIGHT and one DARK monster from the graveyard, has high ATK, and has an effect which requires its controller to pay 1000 Life Points, but 1) sends every card in both player's hands and on the field to the Graveyard, and 2) does 300 damage to your opponent for each card that gets sent to the Graveyard by this effect. Keep in mind, the card effect doesn't say destroy, it says send. Therefore, cards such as Stardust Dragon can't stop it. This generally ended games. If it didn't, then something much worse awaited that ensured all hope was lost...
    • Yata-Garasu, which is quite possibly the most effective card in all of Yu-Gi-Oh!, period. What does this small, black, yet supernatural bird do? If it damages your opponent, they must skip their draw phase next turn, which means that they get no new cards to have any chance to do anything. It also leaps back to the summoner's hand at the end of each turn, making it difficult to remove from the game. This means that if they have no summonable monsters in their hand, you win. This card made decks with more than three or four monsters that required sacrifices suicide, and forced dramatic changes in tactics if you even thought your opponent's deck contained it.
    • Tribe Infecting Virus was non-restricted mass destruction at best and a guaranteed monster snipe at worst. Not only that, combined with previous Game-Breaker Sinister Serpent it would be free mass destruction. Not surprisingly, it was one of the first monster cards limited and then forbidden and hasn't left the list ever since October 2005. Even if one were to try and argue that mass monster destruction isn't as game-breaking as it used to be (hence Raigeki's unban and Dark Hole's semi-limited status), the fact that it's a water attribute and not a once per turn means that it could be abused in much the same way pre-errata Brionac was in combination with Atlanteans.
    • Time Seal skips the opponent's next draw phase. This was used as a Yata replacement for a while in a loop with Tsukuyomi and Mask of Darkness, resulting in the card's ban.
    • Solemn Judgment, easily the best counter trap ever made, allows you to negate any (inherent) monster summon or activation of any spell or trap, at the cost of half your life points. While that may be a steep cost early in the game, it becomes negligible as your LP get lower and ensures it's always live, and the ability to negate any key card or play of the opponent usually made up for this, especially since as a counter trap, there is almost nothing the opponent can do against it. This card was a staple in almost every deck in the game before it was banned in September 2013.
  • Banned toolbox cards:
    • Last Will. Think of Sangan BUT ON CRACK. Tribute, destroy, fuse; whatever you did with your monster, it would immediately get replaced by something else at any phase of your turn, as long as you activated Last Will before. Add the Power Creep that has followed throughout the years and Last Will has become a free tutor for everything broken under the sun. Last Will was banned in March 2007 and hasn't left the list ever since.
    • In the old days of the game, all one needed to do was summon a Cyber-Stein to ensure victory. Cyber-Stein on its own is not that great - terrible ATK and DEF, practically useless, right? Wrong. It has a nasty little effect that lets you summon a fusion monster at the cost of 5000 life points. ANY fusion monster. Like, say, a Blue-Eyes Ultimate Dragon, with 4500 ATK, for instance. Using this effect almost ensures you have less life points than your opponent, which allows you to equip Megamorph (doubling its ATK to 9000) and Fairy Meteor Crush (allowing it to deal damage to defending monsters) to it and attack for game. Arguably considered to be the first One Turn Kill ever invented in the metagame, since life points started at 8000. It was banned in the same list that Last Will was, and while it was unbanned by the OCG, it hasn't left the TCG list ever since.
    • Makyura the Destructor, one of the best cards ever created. Its effect is that during the turn it's sent to the Graveyard, you can activate Trap Cards from the hand. This alone makes it quite useful (it's the equivalent of giving a Mighty Glacier a much faster movement speed, I.E. removing their intended downside), creating all kinds of dominant combos. But, it's also ludicrously searchable too, since it's a Dark Level 4 Warrior type monster. Also, triggering its effect technically doesn't count as an activation, making it nigh impossible to stop, even newer cards like Debunk, Shadow Imprisoning Mirror, and Majesty's Fiend are powerless against Makyura. Unsurprisingly, Makyura has been banned since April 2005.
    • In the earliest days of the game, Fusion Monsters were considered Awesome, but Impractical. While some of the effects were decent, they often required too many resources put into them, and could bite you in the behind if your field gets nuked. In an attempt to make fusions more practical, Konami created Metamorphosis, arguably one of the most conveninent cards in the game. With this card, you can summon any Fusion Monster from the extra deck, by tributing one monster of the level as the Fusion Monster. The intent was to give Fusion based archetypes better access to their Fusions, but arguably it worked a bit too well, as it gave decks that were completely unrelated to the Fusions powerful new options they had no right ever having, and ended up contributing to the infamous Goat format, and while certain ban list cards have gotten weaker over the years thanks to Power Creep, Metamorphosis has arguably gotten more powerful through the years thanks to more and more powerful Fusions being introduced. Banned in September 2007, it's needless to say it is quite understandable why this card is banned.
    • Super Polymerization. At a glance, it doesn't seem too outstanding. With it, you can fusion summon a monster using monsters from either side of the field as fusion material. With how specific fusion requirements usually are, this sounds like a very situational card... Until you realize that there are surprising amount of fusion cards out there that only need monsters of a specific Attribute rather than type or monster to summonnote . Add it a few fusion monsters that cover all the Attributes, and not only can you now hand pick an opponents monster to be sent to the graveyard, but now you also get a powerful monster of your own on the field in the process. With the right cards in the extra deck, it is very possible that could wipe your opponents entire monster field and go for the kill to win the game, and there's nothing your opponent can do about it because Super Polymerization cannot be negated in any way. This proved to be an insanely powerful card for fusion decks, so much so that it was eventually put on the banlist.
  • Banned loop cards:
    • Premature Burial, a graveyard revival card that due to the wording, does not result in the destruction of the revived monster if it leaves the field by any means besides destruction. To further elaborate, any card that returns cards to the hand (i. e. Giant Trunade, pre-errata Brionac, Dewloren, etc.) can lead to revival abuse with this card, more than compensating for the 800 LP more often than not. With Disc Commander, this led to multiple revive-draw loops.
    • Butterfly Dagger - Elma: On its own, it's a very mediocre equip spell whose only upside is its immunity to Spell/trap destruction. However, when combined with spell counter decks, which gain spell counters with each spell card activation, and Gearfried the Iron Knight, which destroys any equip cards equipped to it, what you get is an infinite source of spell counters for such decks. A Magical Marionette with infinite attack power? Go for it. Fuel for the otherwise Awesome, but Impractical Mega Ton Magical Cannon? You got it. Or most infamously, use this combo with Royal Magical Library and Exodia for an easy OTK or FTK.
    • Mass Driver has the effect of tributing a monster to inflict 400 points of damage. That might not sound like much, but once you factor in that it's not a once per turn and the number of times some decks can summon the same monster(s) in one turn, you may start to realize just how abusable it is, especially since it is a spell card. This card was a key part of the infamous Frog FTK deck, which resulted in this card and the aforementioned Substitoad getting banned.
  • Miscellaneous examples:
    • The Dragon Ruler series is quite possibly one of the most infamous examples of Power Creep in the franchise to date. A series of level 7 dragon type monsters with a set of smaller Level 3/4 versions of themselves that can special summon them from the deck. They have a plethora of effects that can enable swarming and rapid summoning of Rank 7 Xyzs, along with a means of getting Light and Darkness Dragon onto the field on the first turn. Sure, you can only use one of their effects per turn and even then only once per turn, but the sheer speed and consistency of these effects more than makes up for it with consistency, power, and other effects and the smaller dragons are instrumental in overriding this limitation. The deck also abused Super Rejuvenation (see above) and Sacred Sword of Seven Stars as draw power and as an extra way to trigger their effects. And it's for this reason that this deck was so widely hated before it even came to the TCG.
      • The field spell that could essentially grab Dragon Rulers out of your deck for free, Dragon Ravine, was banned, to the dismay of plenty of Dragunity players due to it being THE card that keeps the deck competitive. Their draw cards were limited. Their "instant win" cards were banned. The Dragon Rulers themselves were limited. Consider this: Half of the archetype was banned, and the other half was limited. Countless cards have been hit to weaken the deck. And the deck was still a strong contender to the point that the Dragon Rulers themselves became forbidden after the Dark Matter OTK abuse.
    • Spellbooks had their own gamebreaker in the form of Spellbook of Judgement, which is a strong contender for the title of most effective Spell Card ever. How it works is that for every spell card that you activate after you play it, you get to search for a spellbook spell card at the end of the turn AND special summon a spellcaster-type monster whose level is less than or equal to the number of spellbooks you added to your hand. The most popular targets for this were Justice of Prophecy or Jowgen the Spiritualist, a level 3 spellcaster which locks out special summons. Essentially, all one has to do is play Spellbook of Judgement and three other spell cards (not a hard task to do in this deck), and they gain even more extra resources or an instant stun of the opponent and a whole hand of support spells ready for the next turn. Spellbook of Judgment was unsurprisingly banned immediately after its format.
    • Elemental HERO Stratos, the most powerful searcher for the HERO archetype, could either search any other Hero or kill spell/traps equal to the other number of Heroes you had any time its summoned. He's a free tutor, on a powerful monster. It ended up banned in the September 2013 for how easily it could be and was abused, both in the Destiny HERO engine and the Bubbleman engine among others.
    • Legacy of the Valiant released an Xyz version of Black Rose Dragon: Evilswarm Exciton Knight whose effect basically nukes every single card except Exciton himself meaning he can use its effect again. Oh sure he has a lot more downsides than Black Rose such as the inability to inflict anymore damage along with requiring to control less cards but when this card is incredibly easy to summon (Just overlay 2 level 4 monsters) and successfully managed to trigger its effect, you will probably be left with no other cards to recover by the next turn. It was banned in November 2015.
    • El Shaddoll Construct, the biggest boss of the Shaddoll archetype. In addition to being rather big (2800 ATK) it also has the effect to destroy any Special Summoned monster that it battles, which can make it a pain to get over. When it's summoned, you can send any Shaddoll card of your choice to the graveyard, something that they love, further strengthening you plays, and if it does die, it gets you back a Shaddoll Spell or Trap so you can just replace it with little effort. However, what ended up pushing Construct over the top was how it enabled the deck to splash powerful LIGHT monsters such as the Performages Damage Juggler and Trick Clown, enabling the deck to easily setup rank 4 summons and dominate the field. Combined with the Shaddoll's ability to fuse from deck with the right conditions, it was hit in November 2015.
    • Apoqliphort Towers, one of the bosses of the Qli archetype, reduces the ATK and DEF of all Special Summoned monsters by 500 and, once per turn, he can force your opponent to send a monster from their field or hand to the graveyard, making it even harder to maintain advantage against a Qliphort player. What's worse, he is immune to all Spells and Traps as well as the activated effects of all monsters with a level or rank lower than his own. Being Level 10, this guy shrugs off almost everything. Some decks in the format just outright lost due to not having an out to Apoqliphort Towers. To overcome Apoqliphort Towers, you need a Level or Rank 10 or higher monster with a removal effect or a monster that retains at least 3000 ATK when it battles this guy. This got bad enough that Konami resorted to more or less killing the archetype completely by limiting Scout and straight up banning Towers.
    • Tellarknight Ptolemaeus: At first glance its nothing special, a Rank 4 with low ATK but high DEF, except for one thing, it can ditch 3 Xyz materials to bring out a Rank 5 monster (Provided it isn't a Number), Constellar Pleiades? Became a staple, Stellarknight Constellar Diamond? There are now two ways to get it out. Cyber Dragon Infinity? The most infamous combo with Ptolemaeus to summon this bad boy out; use its effect to summon Nova and then Summon Infinity immediately. And getting the materials for this effect is easy; not only can you use more than 2 monsters to summon it, but you can also attach a Stellarknight Monster to it as well every end phase.
    • Majespecter Unicorn - Kirin is one of the most powerful and feared pendulum monsters ever made. Its home Majespecter archetype ironically had difficulty making good use of it. Other Pendulum decks with wider scales however can simply bring it out time and time again with ease, and use its effect to bounce any of your opponent's monsters. Add the inherent destruction and targeting immunities of the Majespecters and you have a very difficult to kill, recurring removal card. Both the OCG and TCG ended up Limiting (and later banning) the card after it became clear that every Pendulum deck would run it; Kirin was just that good.
    • Elder Entity Norden, quite arguably the best fusion monster the game has seen, is a Level 4 Fusion monster that can summon any Level 4 or lower monster from your graveyard upon Special Summon, though its effects are negated. Sure it requires two Synchro/Xyz monsters or one of each to Fusion summon, but it can be Special Summoned by Instant Fusion, potentially giving you advantage and very easy access to any Rank 4 or Synchro monsters that are between level 5 and up to Level 8, so much so that it turned Instant fusion, previously a niche card that only saw use in a select few decks, into a staple card overnight. Its water attribute also made it very easy to target another water attribute monster to summon Bahamut Shark, which gave easy access to Toadally Awesome (see Arc-V folder). Not to mention it can be abused with the aforementioned Super Polymerization (also banned). Most importantly, it does not have any Summoning restrictions and can be used multiple times per turn! (Several OTKs and FTKs can be achieved very easily with Norden. Here is an example.) Because of that, it is now banned in the OCG. It remained Limited in the TCG for a while, until a powerful combo involving Zoodiacs came to light, contributing to Zoodiacs completely dominating the Top 32 of a Yugioh Championship Series tournament, which ended up being the final nail in this card's coffin.

    Duel Monsters 
  • One of the first Game Breakers (and a major sign of later Power Creep) was Jinzo. It combined a powerful effects and good stats in a one-tribute body, making any traps cards (except those negating his summon) useless. Before long, Jinzo was in every Deck that could afford him and then some, and the average number of Traps in Decks dropped from ten to three. Jinzo would be one of the first limited monster cards, and his reign of terror would last for years, only fading when Monarchs muscled in on his turf. Jinzo influence on deckbuilding was so big that even years later, players would be wary of filling their deck with trap cards lest Jinzo would make them lose on the spot.
  • Exchange of the Spirit, a card that was banned on TCG banlists before its official export to the TCG. While it was much milder than other game breaking cards in the sense that it gave you a turn (and that is only if you consider entering your draw phase as getting a turn) it became devastating because you could easily win by milling your deck whether or not to search the card you wanted, end your turn, activate the trap, mill the opponent's entire deck to the graveyard and force your opponent to draw. The only reason it's currently unbanned is due to an errata which added the condition that both players needed to have 15 cards in the Graveyard before Exchange of the Spirit can be activated, and that only 1 Exchange of the Spirit can be used per Duel.
  • Crush Card Virus, which, in the TCG, was notorious for being one of the most difficult and expensive cards to obtain for yourself, due to being released initially as a Shonen Jump prize card and otherwise only available as a gold rare from the limited release (original) Gold Series until shortly before it was banned outright. Though the card's effect drove the card's price just as much as the difficulty of owning one. Its effect effectively renders so many decks unable to play monsters, that it's easier to list what decks wouldn't be affected by it (even to this day). The card was so strong, that anybody who was lucky enough to have a copy would play cards (most commonly Sangan and/or D.D. Crows) just so they could use the card against the opponent. As such, the card was eventually banned and stayed on the list for years until it got an errata changing the 3 turn duration into the opponent getting to destroy up to 3 1500 or more ATK monsters from the deck and also making the opponent immune to damage until the end of the next turn after its activation.
  • The Envoys. Good God, The Envoys. These cards, when used in tandem with a certain other monster i.e. Yata-Garasu, are the very reason that the Forbidden / Limited list exists today. Not only were they dirt-cheap to summon, they had extremely potent effects that wouldn't be replicated for years to come. Their abilities were so effective that, for a long time, they completely dominated the metagame. If you were not using a deck that utilized these, your chances of winning dropped by 90%.
    • BLS - Envoy of the Beginning. Could remove anything for free or would badly hurt your opponent thanks to its double attack effect and gigantic stats. It was banned for many years until Konami gave it a second chance and made it Limited to only 1 per deck.
    • Chaos Emperor Dragon - Envoy of the End is the other one, often considered one of the strongest cards ever created in the game (See banned cards).
  • Magician of Faith has probably the best set up for recycling Spells from the graveyard ever. Given how it allows for permanent application of Spell cards that allow for quick Special Summons and easy searchers of the monsters in the deck that combined make a fearsome combo and you have enough reason for why a card like this was banned. The card was unbanned in the TCG in the January 2014 format and eventually unlimited altogether due to a lack of spectacularly effective spell cards to recycle and how slow flip effects have become due to Power Creep.
  • Skill Drain is a card that negates every single monster effect on the field at the cost of 1000 life points. Not only is it one of the greatest ways to lock down the meta since effect monsters took over, and prevent many decks from doing anything useful, but it also negates the effect of monsters that have high ATK yet are balanced by a monster effect that works as a drawback that prevents them from becoming too dominant. In addition to that special summons from monsters in the hand or deck are not negated by this card, which allows decks build around it to pick up speed. It is thus not an exaggeration to say that entire decks are built around it that might still have some competitive value even in the meta of today. Leaving and entering the banlist depending on the phase of moon, the card was finally limited in April 2015 thanks to its interactions with Qliphorts (see Arc-V folder).
  • Thousand-Eyes Restrict. A level 1 Fusion monster with bad stats but extremely nasty effects; normally, you'd need a specifically designed deck to bring this thing out, but thanks to certain other banned cards (Metamorphosis, Tsukuyomi, Magical Scientist, and Magician of Faith), one could make a deck without the fusion card to bring it out. It single-handedly created an entire format that was so slow that the creators hit the deck harder than any other deck has ever been hit with the banlist, banning EVERYTHING that made the deck even remotely usable.
    • Oh, and guess what? As of April 2016, Thousand-Eyes Restrict is back. This should speak volumes about the sheer Power Creep the game has gone through and the nature of some of the other game breakers listed here.
  • What do you get when you combine the aforementioned Envoys and Yata-Garasu into one deck? The Yata-Garasu Lockdown, or "Yata-Lock" for short, one of the most legendary-for-all-the-wrong-reasons decks from the early days of the game. This deck relied on using the field nuke effect of "Chaos Emperor Dragon" while either "Sangan" or "Witch of the Back Forest" (allows you to search out a weak monster when destroyed) to fetch "Yata-Garasu" from your deck, and since you just emptied your opponent's hand you could then proceed to merrily cherry-tap them to death with them remaining completely powerless. It got so bad that the Yata Lock is frequently rumoured to be the reason Yu-Gi-Oh has a banlist at all.
  • Imperial Order, one of the first cards ever banned, is the only continuous Spell negation trap card in the game, but requires you to pay 700 Life Points during each of your Standby Phases. This card, alone, can win games by stunning any spell card based deck to the point of being unplayable if they can't answer it. And if that weren't bad enough, its "downside" actually just makes it so that you can cancel its effect before your turn starts, giving you an insane strategic advantage while it's on the field. It took this card over a decade to leave the banlist, and only after receiving a heavy Nerf via errata: its Life Point cost became mandatory and now must be paid on both players' Standby Phases. And even after its nerf, the card remained extremely effective, being a semi-staple of tier 1 decks after its re-release.
  • Brain Control was designed to be a balanced version of the long-Forbidden Change of Heart, with it having a life point cost of 800 and being able to target only face-up monsters. But even with these additional downsides, it still proved too powerful a card for the game and eventually found its way to the ban list as well, only coming off after being Nerfed to only affect monsters that can be Normal Summoned, thereby limiting a lot of its versatility.
  • Ring of Destruction, one of the most powerful burn cards in the game's history, had the effect to target and destroy any monster on the field and inflict damage to both players equal to the attack of the monster destroyed. Pretty much, just target any monster and you can inflict massive damage to the opponent. Sure, you will take it too, but at worst, it would result in a tie if used well. Also, there was nothing preventing a player from using it on their own monster, which might sound like a -2 on paper, but in practice, was like getting an additional attack against the opponent with a powerful monster, easily and frequently closing out games. The card was only able to come back via errata, limiting its usage to the opponent's turn against an opponent's monster whose attack is less than or equal to their current life-points, and making the player using it take the damage first, removing most of the card's utility. However, even with these nerfs, it remains a powerful staple in burn decks, ensuring it remains limited to this day.

    GX 
  • The Destiny HERO engine, which used Malicious as a Tribute and later as Synchro fodder. It had a good draw engine with Destiny Draw and Disk Commander, and comes in DARK which has awesome Graveyard support. 2 format-defining Decks used this engine to fuel their combo: the powerful Tele-DAD, and Perfect Circle, which combined Disc Commander with Monarchs and Light and Darkness Dragon to make a "circle" of plays that gives continuous advantage. By reviving Disk Commander every time LADD dies, you draw two cards, and you could use it as Tribute for Monarchs or another LADD. It ended up with Malicious getting a semi-limit and Destiny Draw being limited for a while.
    • But that was only one reason behind Disc Commander's banning: it was also used heavily with Premature Burial (see banned section).
  • Demise, King of Armageddon is a level 8 Ritual monster. By itself, it's an over-costed Judgement Dragon with less ATK. However, with the release of Advanced Ritual Art and other cards, it became the center of a very consistent One-Turn Kill combo. The deck was versatile; it had multiple ways to OTK or otherwise deal extremely high damage thanks to insect support and equip cards such as Megamorph. This deck was so powerful, it resulted in many of its key cards (namely ADA, Megamorph and Demise) getting hit on the limited/forbidden list including Demise becoming the first ritual monster to be hit by said list.
  • Lightsworns. Many of them have simple, strong effects, but force you to send cards from your Deck to your Graveyard. This is less of a drawback than it seems—it's much easier to revive monsters from the Graveyard than to recruit them from the Deck (some, like Wulf, Lightsworn Beast, revive themselves), and support cards like Lumina, Lightsworn Summoner and Beckoning Light can use the Graveyard as an extra Hand. The archetype's trump card, Judgment Dragon, has 3000 ATK, is Summoned when you have 4 or more different Lightsworns in the Graveyard, and can nuke everything else on the field for low cost. The Lightsworns were also easily able to splash graveyard-based support such as Necro Gardna. The deck eventually got hit by limiting Lumina, Judgment Dragon and Charge of the Light Brigade. Even then, the deck would remain a top contender for years to come thanks to additional support and other Game-Breaker cards on this list.
  • Related to LIGHT decks is Honest. Because it activates in the hand and has a specific timing that dodges most defensive cards, you are pretty much guaranteed to overpower any monster. Back when you could use more than 1, you could win any battle AND inflict massive damage no matter what monster you were using. It ended up being semi-limited and then limited for most of his history.
  • One other handtrap that would be released in the GX era and arguably a biggest Game-Breaker was Gorz the Emissary of Darkness. No longer it was safe to mindlessly try and attack for game on an open field, unless you wanted to give your opponent two absurdly strong beaters and allow them to stage a comeback, but the card was also extremely powerful against Burn decks. Gorz was limited only 1 format after it was released, in March 2007, and would only come back in April 2015, but by then, it had already left its mark into the psychology of the entire game. Veteran players still attack with ascending attack ordernote  in order to avoid Gorz as uncommon as it may be now and also to avoid other hand/traps.
  • GX Era Monarchs. Using floatersnote  and other Game-Breaker cards on this page, the Monarch deck managed to win the World Championship 2007. Using Confiscation and Trap Dustshoot (see Banned folder) to know the opponent's hand and snipe it with Thestalos the Fire Monarch, while controlling the field with Raiza the Storm Monarch with Brain Control and Snatch Steal to provide more tribute fodder, the deck was too much for the rest of the meta to handle. The Monarch deck was also the most prominent user of what was known as the Troop Dupe Scoop enginenote . The deck was the final nail in the coffin for many of the Game-Breaker cards on the list (Confiscation, Ring of Destruction and Snatch Steal), while also getting Card Trooper and Raiza Limited in the September 2007 and March 2008 lists respectively.
    • After these hits and Power Creep kicking in, Monarch still remained a top contender thanks to the addition of Caius the Shadow Monarch and the Frog engine, becoming the (in)famous Frog Monarch deck. Fortunately, it was not nearly as oppresive as the 2007 version. Come January 2016, however... (see Arc-V folder)
  • Dark Armed Dragon was Envoy of the Beginning Part Deux. Its effect isn't restricted to a certain number of uses per turn, meaning that without any outside factors you would be able to nuke 3 cards once it got to field. DAD was the star of the many decks, and is commonly splashed into anything that has DARK monsters and Graveyard manipulation.
    • The Dark Armed Dragon deck that created the ban list discontinuity was DAD Return, the first deck to receive the honor of an emergency banlist. By removing powerful monster cards (e.g. Dark Magician of Chaos, who returns a used Spell Card to your hand when summoned) for the effect of Dark Armed Dragon and Allure of Darkness, you increase the number of monsters that will come back with Return from the Different Dimension/Dimension Fusion while speeding your approach toward drawing those cards. You then create a loop of powerful creatures by grabbing Fusion through DMOC's ability and continue until you win. Like Envoy and Yata-Lock decks before it, this strategy was infamously considered to be nearly impossible to beat unless you were playing it yourself, leading to a ton of homogeneity at tournaments and its main components being limited on the aforementioned first emergency banlist.
  • Wall of Revealing Light seems okay at first glance. Highly risky, but could help you set up for a few turns, but its main usage wasn't this. Its cost can tank your Life Points low so you could use certain other Game Breakers with ease, such as Last Turn, Self Destruct Button and helped for the activation of powerful cards such as Megamorph. The main combo that got it limited was using it alongside Magical Explosion and Life Equalizer to OTK your opponent.
  • Future Fusion. At first glance, it's an extremely slow back row target that'll net you a fusion monster from your deck every once in a few blue moons. However, what seems like a mediocre fusion card at first glance hides one of the single best mill/graveyard setup cards in the game. When combined with cards that have high fusion material costs, such as Five-Headed Dragon, this card allows you to hand-pick cards (five dragons in this case) from your deck to the graveyard. With how graveyard-centric the game is, this is an amazing setup card, especially with other cards that can abuse cards in the graveyard such as Chaos Dragons, The Envoys, and the aforementioned Dragon Rulers. Generally, once you have this card in your hand, it's practically good game for your opponent. On top of the setup, it would net you a free beatstick on the following turn. Needless to say, there's a reason this card ended up getting banned. Future Fusion returned in the March 2017 format of the TCG, sporting a new errata: the Fusion Monster is chosen, and the Fusion Materials sent to the Graveyard, on the first Standby Phase after its activation, thus giving the opponent a turn to respond and stop you from filling up your Graveyard.
  • Gladiator Beast, an archetype with the gimmick of being able to "tag out" into others of their own after battling. The deck was the first of many to be able to toolbox their way out of any situation, thanks to monster and spell/trap destruction, graveyard banishment or simply beating up the opponent. However, it doesn't end there, as Gladiator Beast were also the first archetype to make effective use of the Extra Deck, making use of Contact Fusions and refining them. Having access to spell and trap negation and mass destruction, the deck ended up winning the World Championship 2008. The limiting of Gladiator Beast Bestiari in March 2009 (arguably the best Gladiator Beast maindeck monster thanks to its effect and being a mandatory material for Gyzarus) along with the Power Creep that the Synchro era brought ended up burying the deck for good.
  • Rescue Cat, a prime example a card becoming rather deadly due to Power Creep, was originally just a tutor somewhat limited by the single turn duration of the monsters it retrieves from your deck, which can only be beasts of level 3 at the highest. Gladiator Beast gave it a shot in the arm. Then the Synchro era happened, and X-Saber Airbellum, a powerful level 3 beast tuner, was available from the start. Cue mass first turn Synchros. The card ended up on the semi-limited list, advancing each successive year until it was forbidden in March 2010. To solidify how severely devastating Rescue Cat had become due to such progression, with the release of certain Xyz/fusions to use alongside Synchros, first-turn kills were possible using Rescue Cat alone in previous Traditional Formats. It only came off the ban list because of an errata that made it a true once per turn effect and negates the effects of the monsters it summoned.

    5D's 
  • Some Synchro monsters have reached this Level; the requirements needed to summon them (a Tuner and non-Tuner monsters, whose Levels add up to the Level of the Synchro Monster) work insanely well with popular aggro-swarm tactics, making them staple cards in almost all decks. Key offenders include:
    • Dark Strike Fighter, a Level 7 monster that can sacrifice monsters to deal damage equal to their Level x200. Sounds simple? A direct attack from this card plus its own effect does damage equal to half of your Life Points. Which means if you'd taken a bit of damage already (or there were other monsters to attack and sacrifice), this "finisher" ended games on the second or third turn. The worst part was that it was an inverted Nerf from the anime that removed the factors that would have made it balanced: the effect only being allowed once per turn, preventing it from attacking on the same turn, and that it could not sacrifice itself for its effect.
    • Goyo Guardian, a Level 6 monster with stupidly high attack and a nasty effect. In the early days of the Synchro era, it was one of the most spammed synchro monsters. It was banned, and no other level 6 synchro came to equal it for a while, Gaia Knight being the next best thing but with no effect. Goyo was later unbanned in the TCG due to Power Creep. In a funny inversion, the OCG seems to fear Goyo Guardian so much it was errata'd to require an EARTH tuner... 2 years and a half after it was unbanned in the TCG and doing absolutely nothing.
    • The Ice Barrier Synchros are (in)famous because of their power. All of themnote  have hit the list in one way or another;
      • Trishula, Dragon of the Ice Barrier). While it has a high level and requires 2 non-tuners, it's stupidly easy to bring out on dedicated decks and was one of the key pieces of the infamous Infernity (see below) loop that would get rid of your opponent's hand and field while also OTK-ing on the same turn. What's even better, Trishula's effect doesn't target, allowing the card to stay relevant 7 years and a half after its release. It was Limited, then Banned and then Limited depending on the phase of moon, but it would eventually become Limited and stay that way since July 2015.
      • The Level 6 Brionac, Dragon of the Ice Barrier, was no slouch either. Being able to get rid of your opponent's field and being able to recycle your own cards meant it was incredibly good. For these reasons it was Limited. It kept being strong into the Xyz era, eventually getting banned because of its interactions with the Atlantean archetype (see Zexal folder) and only getting unbanned after an errata that made its effect a hard once per turn and restricting its bounce to the opponent's cards.
      • The also Level 6 Dewloren Tiger King of the Ice Barrier is broken in yet a different way. While its materials are heavily restricted, Dewloren is part of multiple burn and draw loops leading to consistent First Turn Kills throughout the years. While not broken enough to be banned, Dewloren at multiple copies can self-loop. This was what led to its Limited status in the September 2013 banlist. Here are some of the few ways Dewloren can be used at anything higher than 1 copy allowed.
    • T.G. Hyper Librarian, a Level 5 monster that lets you draw when a Synchro Summon happens. Most players would use the newly drawn cards to make more Synchro Monsters, and draw, and so on. In a swarmy-Synchro Deck, it was not uncommon to see two or three on the field at once. Combined with other draw cards and thanks to the absurd summoning speed of Synchro decksnote  it was Limited in September 2011 and hasn't left that spot ever since.
      • Formula Synchron would normally be fair, but thanks to the existence of Librarian it also got Limited in the September 2011 banlist. It would eventually get unlimited, but for a while Librarian + Formula was one of the most effective draw engines in the entire game.
  • Deep-Sea Diva is one of the few Tuners that can summon another monster without restrictions or previous setup. At worst, Deep-Sea Diva is a level 3-5 synchro or a rank 2 Xyz monster. As with Rescue Cat, Diva was not broken on the Synchro era; it was until well into the Xyz era and the release of the Atlanteans that its power shot through the roof. Diva got increasingly more powerful over the years, to the point it became a 1-card OTK or Trishula. For that reason, it was Limited in September 2013 in TCG and once its interactions with the Atlanteans became overbearing, it was Limited in the OCG too. Here's a comprehensive list of all the powerful combos Diva enables with the Atlanteans.
  • The Blackwings. One of the most powerful decks in the Synchro era, the deck had everything to compete; Tuners that special summoned other monsters, battle immunity, quick destruction, special summons, piercing damage... It was so powerful it won the World Championship in 2009. The deck got 3 of its most important combo pieces Limited (they would later come out of the list as power-creep left them behind): Gale the Whirlwind, a special summonable monster able to run over a lot of problematic monsters and deal more damage to the opponent, Kalut, their own version of Honest to deter the opponent's attacks and their partner in crime, Black Whirlwind that enables you to search the aforementioned two monsters and others as long as you had a Blackwing with enough attack on your hand.
  • The Tele-DAD deck, starring Dark Armed Dragon (see GX folder) and Emergency Teleport, relies on card synergy, speed and explosive combos. This is achieved through its amazing draw power (Allure of Darkness and Destiny Draw) and hand/deck customization (Reinforcement of the Army, Plaguespreader Zombie, Emergency Teleport, Dark Grepher, and the old Destiny Heroes engine) since most of its key cards could be run in triple. The TeleDAD deck was so strong, literally NOTHING ELSE could compete. With a good TeleDAD deck, it was incredibly rare for games to last more than 3 turns. It is one of the two honorary holders of the title Tier 0, a title that was previously only held by the Chaos Deck. For a while, ONE copy of Dark Armed Dragon cost upwards of $200. Yes, $200 for cardboard. The deck was so brutally gutted by the banlist, it got no less than ''four'' of its key cards limited and the deck was still able to compete on high-level tournaments, but now without being so oppresive.
  • Plant-Synchro. Plant monsters were largely a forgotten type in the story of the game; however, thanks to additions in the late GX era and the 5d's era, the Plant synchro deck became a top contender. Using Lonefire Blossom to quickly recruit monsters from deck, Glow-Up Bulb and Spore as self-summoning tuners along with Dandylion and Debris Dragon allowed the deck to quickly bring out Synchro monsters while using plenty of graveyard based resources to control the field and defeat the opponent. Plant-synchro key components got Limited at different times to allow other decks to shine.
    • After the limiting of many of its key components, Plants would end up being used as an engine for Junk Doppel, a deck that (ab)used the Synchron tuners (Junk and Quickdraw) along with Doppelwarrior to generate synchro fodder while climbing for increasingly more powerful Synchro monsters. The deck would be the second place runner up for the World Championship in 2011.
  • The Infernity cards. They all share a drawback of not being able to activate their effects unless you don't have any cards on hand, easily achievable with discard cards such as Summoner Monk or Dark Grepher. The deck was rightfully powerful in the Synchro era, being able to loop their effects multiple times and special summon monsters from graveyard while searching key cards and synchroing powerful monsters such as Trishula or Scrap Dragon to whittle down the opponent's field and hand. The first of its limited cards was Infernity Launcher, gimping their swarming abilities and taking away their presence in the Synchro era. However, Infernity got arguably more powerful in the Xyz era, circa 2013; now using Infernity Archfiend to search for Infernity Barrier, their own Solemn Judgment and controlling the field with Xyz monsters, floodgates such as Vanity's Emptiness (see banned folder) and reducing the opponent's options with Infernity Break. Barrier got limited in April 2014, but even with their power cards Limited, Infernity proved powerful enough they ended up winning the World Championship 2014, and the OCG/TCG answered accordingly, limiting Archfiend and finally killing Infernity for good.
  • Six Samurai. An archetype that debuted in the GX era, Six Samurai was a somewhat mediocre beatdown deck. Then Storm of Ragnarok was released and the archetype was updated was massively overhauled with the release of the Legendary Six Samurai and Shi En cards, giving them swarming, searching and control tools, the last in the form of their very own synchro. Not only that, it breathed new life into some of their older cards such as Double-Edged Sword Technique, Six Samurai United and the infamous Gateway of the Six. Between all the draws, the swarming and the searching, Gateway could keep a steady influx of Bushido Counters to swarm and search even more, not to mention access a way to ''loop'' your own cards. And not only that, thanks to their EARTH attribute the deck had access to the powerful Naturia Synchros. Basically, if Six Samurai went first you would be screwed. The deck got hit after only one format in play, by limiting Gateway of the Six, Shien's Smoke Signal and Legendary Six Samurai - Shi En, and got further hit when Gateway proved its ability to self-loop in the Xyz era. Smoke Signal and Shi En would leave the list after proving themselves not broken anymore, but despite further Power Creep, Gateway is still there.

    ZEXAL 
  • Xyz Monsters are Summoned by combining 2 monsters of the same level (sticking them under the Xyz Monster). Cards "attached" to an Xyz Monster aren't "on the field". However, for a short time there was a ruling that monsters whose effects activated when they left the field worked anyways. This led to Tour Guide From the Underworld, a card that can recruit Sangan from the Deck for an Xyz Summon, skyrocketing in price. Players would go for a big Xyz Monster, detach Sangan for an effect, and grab all kinds of monsters at no cost.
    • Tour Guide From the Underworld in general, even without the ruling, is extremely powerful due to its ability to make Rank 3 monsters easily. The Rank 3 monsters available can return low-level banished monsters for reuse, protect themselves from destruction while punishing the opponent for trying, or just stomp on everything with 3000 ATK. Tour Guide would end up Semi-limited, then Unlimited and finally Limited in the TCG in April 2015 thanks to its interactions with Burning Abyss (see Arc-V Folder).
  • Surprisingly, the first Game-Breaker deck of the Zexal era would be something that made little use of Xyz - The Agents. Making use of their very own Stratos, Venus to swarm the field with Mystical Shine Balls and Master Hyperion as their main muscle. The deck also made use of Archlord Krystia and Herald of Orange Light to restrict the opponent's special summons and their monster effects respectively, while also using Mystical Shine Ball as synchro (remember Earth is a tuner?) and Xyz fodder for Gachi Gachi Gantetsu. The deck ended up winning the World Championship 2011, and The Agent of Mystery - Earth was limited in the March 2012 list.
    • Some variants of The Agent deck would use a small T.G. engine to ease Synchro summoning - namely 3 copies of T.G. Warwolf and T.G. Striker. T.G. Striker + Agent of Creation Venus - 1500 LP = Trishula and enough setup to drop Master Hyperion on field. T.G. Striker was Limited in the March 2012 list.
  • The Wind-Ups. They had a Special Summoning combo that takes some luck to set up, but could leave the opponent with zero cards in hand. On the first turn. If the opponent didn't have the fortune of opening up with the right hand traps such as Maxx "C" or Effect Veiler to stop this combo when going second, then they were all but guaranteed to lose afterwards. This landed Wind-Up Carrier Zenmaity, one of the key cards in the loop banned in the TCG, while the OCG went the other direction and banned the other key card, Wind-Up Hunter, instead.
  • Rescue Rabbit. It was supposed to give Normal Monsters, seldom used in competitive play, the chance to be used for quick Xyz Summons. People figured out that you could use it to grab 2 Level 4 Dinosaurs and Xyz Summon an Evolzar monster, giving you Spell, Trap and effect monster negation. As a result, Rescue Rabbit, which was designed to encourage creativity, led to a deluge of nigh-identical Dino Rabbit decks... After its Limiting in September 2013, though, it has become used for its original intent in several decktypes.
  • Inzektors, which turn the notion of costs backward by actually gaining cards when they blow stuff up. If Inzektor Hornet is equipped to an Inzektor, you can detach it to blow up a card. It's used with Inzektor Dragonfly to loop itself multiple times and search cards with Inzektor Centipede. They can also pull off absurd One-Turn Kills by shooting two cards that are equipped to Dragonfly at each other. Inzektors would go on and win the World Championship in 2012, and both Dragonfly and Hornet were Limited in the September 2012 banlist as a result.
  • Chaos Dragons. Combining Lightpulsar Dragon, Darkflare Dragon, Ecipse Wyvern and Red-Eyes Darkness Metal Dragon along with assorted LIGHT and DARK monsters allowed the deck to quickly swarm the field and OTK or create insurmountable fields. The deck also abused Future Fusion (see Banned folder) and Dragon Ravine to dump multiple Dragon-type monsters to the graveyard and enable multiple special summons. The deck ended up landing REDMD on the Limited spot and was what ended up getting Future Fusion banned in September 2012.
  • The HERO's Strike structure deck released some more power cards for the archetype, including these two guys . The deck also introduced some new spells designed specifically for spamming Masked HEROs from the Extra Deck, and the two cards below are souped up versions of existing cards:
    • Shadow Mist = E-Call + spell card searcher.
    • Dark Law = One sided Macro Cosmos with the added bonus of punishing search and/or draw cards.
      • The OCG ended up limiting Shadow Mist.
  • Soul Charge. This spell card can bring any number of monsters back from the grave at a cost of losing 1000 LP each and skip your Battle Phase (Note: This is not an actual cost, so if it is countered, you just merely lose a card). The card ended up enabling the revival of Infernity and allowed the Sylvan archetype to make some quite absurd powerful fields with only two cards. Soul Charge ended up limited 3 formats after its release, in July 2014 and hasn't left the list ever since.
  • The rank 4 Xyz toolbox got some of them starting from the end of the ZeXal era. Level 4 monsters are incredibly abundant in the game and getting 2 of them into the field is piece of cake thanks to multiple special summon enablers. The rank 4 toolbox has answers for practically everything on the entire game and it's certainly one of the key components for multiple of the Game-Breaker archetypes and decks starting from the Zexal era and following through the Arc-V era. Namely, it was the power of the rank 4 toolbox what ended up pushing EmEM/PePe to a near tier zero spot. Rank 4 monsters have no less than four of their monsters banned, being the only rank that has banned monsters purely because of their power.
    • Number 16 Shock Master, the Cold Wave on legs (see Banned folder).
    • Lavalval Chain; free graveyard setup and top-decking (see Banned folder).
    • Number 101: Silent Honor Ark gave it easy monster removal and a stall monsters, and for a while effectively deterred players from leaving special summoned monsters in Attack Position, lest they be left vulnerable to this card.
    • Abyss Dweller effectively stuns graveyard-centric decks and can help the rank 4 user to end the game in the spot.
    • Gagaga Cowboy introduced the concept of a LP safe-zone to the metagame. Being reduced to 800 LP was a death-sentence, as now you were vulnerable to Cowboy, making players more wary with their plays and Life Points.
    • Daigusto Emeral is a mini Pot of Avarice on legs, enabling the player to recover their main deck and extra deck based resources and having a sweet secondary effect for decks using normal monsters. It has only gotten increasingly powerful in the latest years, being one of the key pieces of the Zoodiac deck (see Arc-V folder).
    • The aforementioned Evilswarm Exciton Knight (see Banned folder) allowed the rank 4 toolbox quick mass destruction.
    • Castel allows the rank 4 user to spin anything face-up on field, without any restriction. Castel is so powerful, that it's rumoured its existence was one of the factors that led to the sudden release of multiple targeting-immune monsters in the game, completely transforming the metagame.
    • The aforementioned Tellarknight Ptolemaus (see Banned folder) gave the rank 4 toolbox access to universal negation and removal or quick bouncing.
    • Traptrix Rafflesia, not only immune to traps but also an effective Trap Hole of your liking on legs, being one of the few rank 4 monsters that is not reactive and is a good choice to summon turn 1.
    • Number S39 Utopia the Lighting, a 5000 attack beast that negates everything while attacking (see Arc-V folder).
    • And finally, Tornado Dragon, the equivalent of Mystical-Space Typhoon, quick-effect included.

    ARC-V 
  • Drawing on your first turn. Yes, the powers that be believed that going first gave a player a severe advantage, from being able to make their plays with no repercussions, or to set up plays and make sure their opponent could not play their own. It was decided that in addition to the new rule change introducing the Pendulum Mechanic, players going first would not be able to use their initial Draw Phase. In other words, the first turn of a duel, you only have 5 cards to work with, while your opponent has 6. There's still some proof that going first still has advantages, especially if the deck is designed to setup quickly, but this has nerfed them quite a bit to give the second turn player a better chance to fight back.
  • Duelist Alliance, the first set of the Pendulum era, is widely known as a game-tipping point; until then, Extra deck spamming mechanics had been largely unpunished and main deck monsters had been waning in comparison with extra deck spamming strategies for a while. It and the following set introduced three archetypes that would shape the metagame for years to come; Shadoll, Burning Abyss and Qli.
    • Shaddolls had a few of these; in addition to the Forbidden Construct, largely due to the state of the game at the time of their release. Shaddoll Fusion was the first Fusion Spell since Future Fusion that gave the ability to fuse from the Deck, and proved to be so powerful that subsequent Deck-Fusion Spells had severe restrictions. It didn't help that since Shaddolls have effects that trigger when sent to the Graveyard by a card effect, Shaddoll Fusion allowed players to pick and choose these effects at the right time. They also later got El Shaddoll Fusion, a quick-play fusion spell that helped facilitate plays during the opponent's turn and/or OT Ks, so much so that it ended up being Limited. The Shaddoll also had a variety of Extra Deck monsters with all the Attributes and powerful anti-special summon effects, and were also the final nail in the coffin for Super-Polymerization (see Banned folder), as their extra deck variety would ensure that Super-Polymerization was useful on every match and a cheap topdeck on mirror matches.
    • Burning Abyss, an archetype composed of the Malebranche; small monsters with incredibly effective effects and the extra deck monsters, Dante, Virgil and Beatrice. All of the Malebranche monsters have effects when they hit the graveyard in any way. Mill, discard, destroy, tribute, synchro, fuse; anything that sends them to graveyard will trigger them. The extra deck monsters are more specific, but will still trigger from any form of destruction. Being level 3 DARK Fiend-types, the Malebranche have all kinds of support available to them, the most relevant being Tour Guide of the Underworld (see Zexal folder) and Mathematician. Thanks to the trio of Graff, Cir and Scarm the deck has rank 3 Xyz capabilities without equal and is able to use traps such as Phoenix Wing Wind Blast and Karma Cut to control the opponent's field while still gaining advantage. The deck got a heavy boost once the OCG released an exclusive card for them, Beatrice, Lady of the Eternal that while not a part of the archetype has extremely strong setup and floating effects. Does Beatrice remind you of anything? Of course, since her effect is a carbon copy of Lavalval Chain (see Banned folder) with the added bonus of being a quick effect. Burning Abyss remained strong throughout two years and the dominance of Shadoll, Nekroz, PePe and Monarch and went largely unpunishednote  until the November 2015 banlist limited Graff and the August 2016 banlist limited both Beatrice and Cir.
    • The Next Challengers introduced the Qli archetype. They are a group of Machine-type Pendulum Monsters (aside from Apoqliphort Towers and Apoqliphort Skybase) whose Pendulums Scales are either 1 or 9 and they're all in between that level. They all get effects when they're normal summoned and can always be summoned without tributes at the cost of making their levels 4 and their ATKs 1800 (Special summoning them gets you the same thing). When they're normal summoned, they become immune to the activated monster effects of anything whose level or rank is beneath their own. What's worse is that they can get effects when they're tributed as well; Carrier returns a monster to the hand while Helix destroys a spell or trap. The higher level ones get effects when tribute summoned; Disk can bring out more Qliphorts from the deck which will go to the extra deck since they're all Pendulum Monsters. Scout, their searcher, can add any Qliphort card to your hand at the cost of 800 Life Points, but only while it is in a Pendulum Zone due to being a normal monster, while Assembler regains hand advantage at the end of each turn, again only while in a Pendulum Zone. All other Qliphort Pendulum monsters either increase the ATK of your Qliphorts or weaken your opponent's monsters.
      • People liked to tech in cards such as Skill Drain, Vanity's Emptiness, and Trap Stun. These cards shut down monster effects, special summoning, and trap cards for a turn, respectively. With those out, most outs to Qliphort are useless. In fact, Skill Drain even benefits the Qliport player as with pendulums, they can swarm the field with strong beatsticks that can OTK unprepared players in an instant. Not only can Qliphorts seal your opponent, they can steamroll them as well. The April 2015 list finally dealt with them by limiting Saqlifice, Skill Drain and Vanity's Emptiness (used the entire metagame but mostly abused by Qli) and semi-limiting - 6 months later limiting - Scout. Apoqliphort Towers was banned on the same list (see Banned Folder).
  • The Nekroz.Oh boy the Nekroz. The Nekroz archetype proved to be a devastating addition to the game. Retraining iconic monsters from the Synchro era, the Nekroz were the first deck to make full use of the Ritual mechanic and abuse it to no end. Having extremely powerful effects, ranging from the multibanish in Trishula, the lockdown of Clausolas and Unicore and the colossal attack and snipe effect of Decisive Armor, the deck was no slouch in the power department. Thanks to Manju and Senju, along with Preparation of Rites and Brionac the deck was so incredibly consistent that it was extremely hard for it to brick, while allowing them to make their plays at leisure. The deck got around the main limitation of Ritual Summoning (lack of tributes) thanks to Shurit, Strategist of the Nekroz, Nekroz Mirror and Nekroz Kaleidoscope, the later of which allowing you to send Herald of the Arc Light to graveyard and search more Ritual components. The deck even had a way to recover Ritual monsters from graveyard in the form of Nekroz Cycle and all their Ritual spells were self-recycling. And this wasn't the end of it, as all their Ritual monsters had self-discard effects that protected their monsters from targeting, destruction and battle. The combination of extremely powerful plays along with consistency that not even Dragon Rulers at their peak had and the protection, made Nekroz a tier zero deck. Add to this the infamous Djinn Releaser of Rituals lock (see Banned folder) and an entire format was spent between Nekroz players trying to make their plays and Nekroz players trying to break the opponent's boards. Having an out to the Djinn lock was a necessity in this format. The deck was later justifiably gutted with the Limiting (and later banning in the TCG) of Shurit, Unicore and Preparation of Rites, the Semi-limiting and later limit of Nekroz of Brionac, and the banning of Djinn, Releaser of Rituals. No other deck had been hit as hard since the Dragon Rulers.
  • The TCG exclusive Kozmo archetype (whose cards are a combination of Star Wars and The Wizard of Oz) is a deck built around the low level non-tribute Psychic-type monsters having quick effects (meaning they can activate at most any time) to summon higher level Kozmo monsters and each has another useful effect at a life point cost and high level Machine Type monsters that would otherwise have to be tribute summoned banishing themselves upon destruction to summon lower level Kozmo monsters and having extremely useful effects, ranging from targeting protection and negation of spell, traps and monster effects on the higher level ones to all kinds of swarm and searching effects on the low level ones. With its initial release of only 5 cards, it was already a top competitor in the meta, but then it got even more support that pushed it way over the top, not helped by almost all of its low level monsters being searchable by Emergency Teleport. While each monster and card in the deck has its uses, by far the best one is the following:
    • Kozmo Dark Destroyer, a level 8 dark monster with 3000 ATK, which, combined with the Infamous Farmgirl/Emergency Teleport combo, is insultingly easy to One-turn kill the opponent by using it on your own monsters to trigger their floating effects. Combining targeting protection, monster destruction upon summon, and a floating effect made a pain in the ass to deal with it. Both it and Emergency Teleport later ended up being Limited in the August 2016 list.
  • Cyber Dragon received Infinity in Crossed Souls, which combines effects of other Extra Deck monsters to create an absolute monstrosity; it's easy to bring out, it can absorb opponent's monsters and negate opponent's effects while also having a sizeable attack. Infinity was one of the main reasons Tellarknight Ptolemaus (see Banned folder) got banned, and from then on multiple decks have splashed LIGHT Machine-type engines (namely ones using Galaxy Soldier and/or Instant Fusion) to get Cyber Dragon Nova out and be able to access this monster.
  • The 'Utopia' archetype gets more and more support and variations as time goes on, but its latest boss monster is arguably one of the strongest things ever created. Meet Number S0: Utopic ZEXAL. It can be summoned by discarding a Rank-Up-Magic (RUM) spell from your hand and overlaying onto a Utopia monster. (Note that this is any Utopia monster, not just the Rank 4 ones). Ends up being a Game-Breaker since its addition to the game makes sure Konami will never print a consistent RUM searcher to prevent the summoning of this monster from being consistent.
    • Then there's Utopia the Lightning. Having 2500 attack, an one or two-times boost to 5000, immunity to any kind of trick while attacking and the ability to negate any kind of floating, he was at first a very welcome to a metagame where Qliphorts were ruling, since most players finally had an easy out to the infamous Apoqliphort Towers. However, people soon noticed how Utopia the Lightning could not only dispatch basically every monster in the game with very few possible answers, while also giving rank 4 decks yet another powerful addition to their toolbox. Needless to say, cries for an Utopia the Lightning ban have been endless since its TCG release.
  • For a brief while, one of the most meta defining cards of this era was Wavering Eyes, a quick play spell card, and a very powerful pendulum support card. It has been brought back in the September 2017 banlist, likely as a way to attempt to accommodate for the heavy Nerfs the mechanic has received in the Vrains era. As for its effect: It destroys all pendulum scales on the field and also gains increasingly powerful additional effects, based on the number of cards destroyed (and it's not a once per turn use either):
    • 1 or more: Inflict 500 damage to your opponent. Did the card more harm than good, since Performage Damage Juggler (also banned) could negate it. But, it was occasionally used to finish games.
    • 2 or more: You can search any pendulum monster from your deck. Not only is this incredibly devastating against an opponent's pendulum scale setup, but you can just as easily use this card to destroy your own. This sounds counterproductive, until you realize that not only can this set up for a pendulum summon and trigger cards such as Performage Plushfire (also banned) and Guiding Ariadne, but there are also pendulum cards that search other scales, like Performapal Monkeyboard and Qliphort Scout (Banned and Limited respectively), allowing for an instant pendulum summon of the monsters destroyed by Wavering Eyes.
    • 3 or more: You can banish any card on the field. At this point, not only have you destroyed at least one of the opponent's scales and gotten a search, but you also get to banish another one of their cards on the field. Oh, and this effect doesn't target either.
    • 4: You can search another copy of Wavering Eyes from your deck. So, on top of all of the above effects and destroying the opponent's pendulum scales, you also get to search another copy of this card. And, since it's a quick play, you can set it and activate it when they try and get their pendulum scale setup next turn, getting the 2 effect at minimum. Needless to say, it was extremely rare for an opponent to come back from getting blown out by this effect.
  • Decks that combine multiple engine and archetypes without specifically focusing on one aspect of them are largely known as "good stuff" decks. Prominent at the start of the game, they would largely disappear from the meta radar for a while (exceptions such as HATnote  notwithstanding) thanks to Konami focus on archetypes. Decks of this kind tend to arise from unintended interactions between cards/engines and so they tend to dominate their metagames. PePenote  would be the most powerful of them and one of the top contenders for most powerful deck in the history of the game. The deck components need to be analyzed separately to understand why it was so powerful.
    • Performapals. A Tier-Induced Scrappy for many months after its introduction, the Performapals lacked the makings of a good deck, relying on battle shenanigans as their main gimmick. Cue the release of the Master of Pendulum structure deck and Skullcrobat Joker, a Stratos for the Odd-Eyes, Magician and Performapal archetypes. 2 months later, Breakers of Shadow was released, bringing Monkeyboard, the Performapal very own Scout and Pendulum Sorcerer, a Spellcaster whose effect allowed to destroy and search for more Performapals. They also had access to a small draw engine in Lizardraw and Guitartle.
    • Performages. Released in Clash of Rebellions, the Spellcasters had already been somewhat successful by mixing with other archetypes (namely Shaddolls and Heroic Challenger) and abusing the effects of Damage Juggler and Trick Clown to search and swarm the field. Trick Clown effect allowing for effective rank 4 fodder was the main claim to fame for the Performages before Dimension of Chaos. This booster brought the Pendulum monsters, Mirror Conductor and Plushfire. Plushfire effect was extremely broken, since being destroyed in the Pendulum scales triggered its monster effect, recruiting any Performage from deck.
    • Dracoslayer. Luster Pendulum ability to search for any Pendulum monster while also destroying them was without equal. Also part of the Dracoslayer archetype, Ignister Prominence had two powerful effects; to recruit any Dracoslayer from deck and also destroy any Pendulum card on the field to shuffle any other card on the field. This effect doesn't target either. Finally, Draco Face-Off allowed you to place any Dracoslayer on field or the Extra Deck on demand by just splashing a few copies of the Dracoverlords.
    • What largely follows is an obvious conclusion; by using the Performapals and Dracoslayers to search and destroy your Pendulum monsters, you would be able to trigger the effect of Performage Plushfire, recruiting Trick Clown and Juggler from deck while abusing their floating effects to spam multiple Xyz monsters in the same turn. Thanks to the Performapals and the Dracoslayers the deck had insane consistency, and the extra deck monsters Ignister, Trapeze Magician and the entirety of the rank 4 toolbox (specially Tellarknight Ptolemaus, see Banned folder) ensured the deck was no slouch in the power department either. The deck also abused Wavering Eyes (see above) to have another way to trigger their Pendulum effects while also searching for Monkeyboard or Joker to complete their scales. The deck was so powerful it dominated the OCG for an entire format and the entire playerbase was wary of what would follow once they were released in the TCG...
    • Konami answer? PePe would be the reason for the second emergency banlist in the history of Yu-Gi-Oh!, 9 years after DAD Return was the culprit for the first. In February 2016, Konami would release a tournament focused list that banned Performage Damage Juggler, Performage Plushfire and Tellarknight Ptolemaus while also Limiting Luster Pendulum, the Dracoslayer, Performapal Monkeyboardnote  and Performapal Skullcrobat Joker. The real April 2016 banlist would follow these hits and also ban Wavering Eyes and Limit Ignister Prominence, the Blasting Dracoslayer and Draco Face-Off for good measure. What remained of PePe would mix with Odd-Eyes and Magicians and would stay a prominent meta threat until Power Creep caught up to it. To elaborate, the dying remains of PePe would go on and give Kozmo, Monarch and Burning Abyss a run for their money until Autumn 2016.
    • Here is a list of PePe most prominent combos and an analysis. As you can see, at its peak the deck was so crazy it was able to go plus 10 out of 3 cards on hand and create an extremely formidable field that with enough luck would leave your opponent unable to entirely play the game.
  • The Monarchs had already been a Game-Breaker in the GX era, but the rampant Power Creep left them behind for many years. Come January 2016 and Monarch receive a new wave of powerful support in the structure deck, Emperor of Darkness. Not only did the deck get two new powerful tribute monsters that gave the deck access to non-targeting removal and swarming, they also got Pantheism of the True Monarchs, the practical equivalent to a Pot of Greed, Domain of the True Monarchs to prevent access to the Extra Deck, make their monsters into powerful beatsticks and ease the summoning of their high level monsters and The Prime Monarch to recycle spent spell and traps while also being a recurrent tribute fodder while in graveyard. They also got the Squires, Edea and Eidos to facilitate the summon of their tribute monsters even more and recycle their spent resources. This allowed the Monarchs to effectively use previously released support; March to make them extra resilient, Tenacity and Return to search for spell/traps and monsters respectively and finally, The Monarchs Stormforth as non-targeting removal that used the opponent's monster as tribute fodder. The deck was one of the few able to compete with full power PePe. That should talk volumes about its power. The August 2016 banlist hit many of its key components, Limiting Ehther, Pantheism and Stormforth.
  • Remember Frogs? Well, they got Toadally Awesome. Its swarming, setup and negation effects all in one small package make it an incredibly powerful threat, not to mention it does not have any summoning restrictions and can be summoned with Bahamut Shark to abuse its negate-then-set effect like there's no tomorrow. WATER decks (and even decks that used just one copy of WATER monsters, such as HERO) would largely abuse this loophole by using Elder Entity Norden (see banned folder) with Instant Fusion to revive their WATER monsters and get free negations.
  • A lot of the cards in the metagame are powerful because they are "unaffected by card effects", and others can negate almost anything. Cards that tribute them as part of a Summon Mechanic, however, are not considered "card effects". This means that cards that tribute monsters from your opponents side of the field to summon themselves there are extremely potent counters to the likes of "Ultimate Falcon", "Kozmo" starships, "Cyber Dragon Infinity" and "Crystal Wing Synchro Dragon". The problem? Lava Golem, Volcanic Queen and Santa Claws are not exactly searchable; and while they are strong, they use the normal summon or allow your opponent to plus. Meet the Kaiju. The spell Interrupted Kaiju Slumber destroys all monsters on the field, then summons a Kaiju to each side, basically being a souped up Dark Hole. And that's not all. Slumber has a graveyard effect that allows you to search for any Kaiju monster the turn after it's used. As such, Interrupted Kaiju Slumber is Limited in the OCG lists and Semi-Limited in the TCG lists as of April 2017.
  • Zoodiacs. Their main claim to fame is the fact they can Xyz Summon using a single monster, a mechanic that was already game-breaking enough in the ZEXAL anime, to the point that every single card that had this effect was changed when coming to the card game. Not only offer up to seven free Xyz Summons per turn, but also are EARTH Beast-Warriors, giving them some of the best support in the game such as M-X-Saber Invoker and Fire Formations — but that's not the worst part. What makes them truly gamebreaking is Zoodiac Ratpier. Her first effect allows access to an easy themed Pot of Avarice, allowing for neverending combos even if your opponent clears the field. Her second effect makes any Xyz Monster that he's attached to able to detach a Xyz Material to summon another Ratpier from the deck, and the "once per turn" in the card is not a "hard once per turn", what means that multiple monsters can use this effect multiple times. Combine this with one of their Xyz monsters grabbing materials from the grave and another having a destruction effect that works in either player's turn, and you get a ridiculous engine that can spam Extra Deck monsters and build up a solid field FROM A SINGLE CARD. At its peak, the Zoodiac engine (Ratpier, Barrage and the extra deck Zoodiac), featured in so many Decks that all decks gave a try to splash it as any deck would largely benefit from it. The Deck as a whole, meanwhile, proved so game-breaking that the Zoodiac engine got hit hard in the April 2017 OCG lists: both Drident and Barrage are banned and Ratpier is Limited (Semi-Limited in the TCG); Drident because her effect was far too powerful and easy to access, and Ratpier to cripple her ability to summon monsters en masse.
    • And even after the hits, the deck was powerful it kept being tier 1 even with almost all its power plays banned, leading to the banning of Zoodiac Broadbull in the OCG in July 2017.
  • Although released during the GX era, Instant Fusion has become one of the most controversial cards ever. Its ability to special summon Fusion monster bypassing the materials requirements is without equal in the entire game. Here are some infamous combos involving this card:
    • For starters, see "Thousand-Eyes Restrict" in the "Duel Monsters" folder and "Elder Entity Norden" in the "banned" folder.
    • Independent Nightingale can be summoned with this card. While it's considerably less powerful if it isn't Fusion Summoned, it can be used with The Tyrant Neptune to summon a monster with 6000 ATK—insurmountable even with Utopia the Lightning—immunity to card effects bar a special few, and 5000 burn damage every turn. It bears mentioning again because of how stupidly good the combo was. Because of this, The Tyrant Neptune is now banned in the OCG and TCG lists as of April 2017.
  • That Grass Looks Greener is a card that thins your 60-card deck out in order to compete with 40-card decks. Oh sorry, we misspoke: Grass Looks Greener puts 60-card decks over 40-card decks. With any archetype that can revive cards from the graveyard, Grass Looks Greener becomes a Foolish Burial on speed, turning your graveyard into your second deck very early in the game. This resulted in its Limiting in the TCG in March 2017.



Alternative Title(s): Yu-Gi-Oh Card Game

http://tvtropes.org/pmwiki/pmwiki.php/GameBreaker/YuGiOhCardGame?from=GameBreaker.Yu-Gi-OhCardGame