Common Knowledge / Yu-Gi-Oh!

• Many people like to complain about how the Duelist Kingdom arc doesn't follow the rules; that's because at that time, the game was a Plot Tumor that basically had no rules to follow, and needed to be made up wholesale (there's even an obscure version of the game made by Bandai that follows a much different set of rules than the OCG/TCG). Similarly, the game actually was a lot more like the one shown in Duelist Kingdom for a brief period in the OCG, with Tribute Summons being nonexistent and Fusions being made with cards on the field exclusively. This period only lasted a few months, due to its rather obviously unbalanced nature; after the "Expert" rules were put in place, the manga followed suit and changed the rules to something more resembling the card game (while still having some oddities, by nature of being made on a weekly grind).
  • Much of this also comes from the fact that the Duelist Kingdom arc is Mis-blamed; it was the people making the card game that were getting things wrong, due to how the card game is based on the manga, not the other way around. For instance, the infamous Catapult Turtle strategy happened because in the manga, the playing fields used in the Duel Boxes are 8x5 grids (8x6 grid in Pegasus' castle), and cards can be placed anywhere in the grid, Catapult Turtle's effect was closer to "tribute a monster, take damage equal to half its ATK, destroy a card on the field", and Castle of Dark Illusions might have been something like "flip all your monsters facedown, when this card is destroyed, destroy all monsters placed beneath it and take damage" (and the Player Killer of Darkness combos Chaos Shield with Castle of Dark Illusions to make his side of the field impossible to attack, thus all his monsters are placed beneath Castle of Dark Illusions and can't "run away" with Chaos Shield around). That the card game didn't reflect either of these things is hardly the manga's fault, which used completely different playing field consisting of 5 Monster Zones and 5 Spell/Trap Zones for starters.
• The Shadow Realm. It is not a place of eternal torment, or an analog to death, and there is actually a place called "the Shadow Realm" in the Japanese anime; it's actually a pocket dimension created around the players of a Shadow Game to enforce the rules of the game and prevent outsiders from interfering, or the players from leaving the game until there is a winner.
• Contrary to what Yu-Gi-Oh! The Abridged Series made many people think, Kaiba did not actually summon three Blue-Eyes White Dragons in one turn in the first episode. He summoned them one each in separate turns, and the only current rule he broke (and which everyone else also broke until the anime began following the TCG's rules) was that he summoned them without tributing.^note Though he is guilty of this exact thing in the "Season 0" anime, multiple times
• Many people have heard that the original manga started out as a delightfully gory Power Fantasy featuring a Villain Protagonist Yami Yugi dishing out ironic deaths to people for minor slights against him and was later dumbed down to a generic Power of Friendship story by heartless executives to better sell cards. In reality, the Power of Friendship theme and numerous lighthearted moments were present from the beginning, Yami Yugi indeed starts off as a dark character but mellows out through real and gradual Character Development, and very few of the victims of his punishments actually died, the ones that did always being outright murderers themselves. The series shifted its focus to the card game well before the actual game came out, and while the shift was indeed imposed by editorial it was done in the interest of saving the series, as the early done-in-one format was extremely unpopular, with the noted exception of the two-parter focusing on the card game. Even after the shift took place the series still had plentiful dark moments as well, including limb-chopping, eye-gouging, horrendous child abuse, and even a Psychic-Assisted Suicide.
• In point of fact, Yami Yugi definitively kills a grand total of one person over the course of the entire manga. There's a few characters with ambiguous fates (the Player Killer) or punishments that could have killed them (Goro Inogashira), and one case of a character who challenged him to a game and put his soul on the line (Imori), but he only ever killed one person via Karmic Death, and that person was a serial killer. Even then, Yami Yugi didn't kill him directly - the guy dropped his own cigarette into the vodka he'd drenched himself in when he relaxed his face out of disbelief his luck had turned.
• By a similar token, many fans will tell you that "Season Zero", the Toei adaptation, is far more faithful to the manga than the more famous anime adaptation. It's not; it just adapted a different part of the series (which has also given rise to the Common Knowledge that it's canon to the other anime, hence the name). Among other things, a lot of plots were given new scenes or added padding, an entire story arc that wasn't present in the manga was added, and a character who was originally a one-off got moved to the main cast. Another common claim is that it wasn't Merchandise-Driven, unlike its successor series. It was; there are multiple one-off episodes added just to show off the cards, and even a Non-Serial Movie dedicated entirely to Red-Eyes Black Dragon. It's just that the game based on it wasn't nearly as successful as the one that would follow. Lastly, there's the idea that it's incredibly dark and violent and 4Kids didn't dub it because of that—the truth is, it was actually mostly Bowdlerised compared to the manga (for instance, the aforementioned serial killer ended up Spared by the Adaptation), and isn't that tonally different from Duel Monsters, featuring lots of goofy comedic moments and wacky plot points. Given that it was a completely separate series and uninvolved with the franchise's main cash cow, it's much more likely that 4Kids simply didn't want to go through the trouble of buying the rights to it.
• Anzu/Tea is universally remembered for doing nothing but making speeches about The Power of Friendship. This happened... maybe twice significantly, one of which was added for the anime, plus a Call-Back to one in a Non-Serial Movie. Considering that friendship is one of the biggest themes of the series, that's pretty thin on the ground. She does make a few other speeches, but they're generally not about friendship. The fact that one of those speeches was in the first episode of the anime probably throws the margin off. Also, while she only duels a handful of times (once in the manga, three times in the anime) and frequently played the Damsel in Distress, she's fairly active in both the manga and the anime (solving traps in Death-T, blowing up Zorc in Monster World, defeating one of the Big Five in Virtual Nightmare, keeping Atem together in Orichalcos, coming up with the cartouche in Millennium World).
• It's common for Yu-Gi-Oh! GX fans to claim that the name of Judai's Superpowered Evil Side, named the Supreme King in most dubs, is "Haou." This is indeed what he's called in Japanese, but that's because "Haou" is just the Japanese word for "Supreme King." Some go so far as to address him as "Supreme King Haou", which translates to "Supreme King Supreme King." The Supreme King simply isn't identified with a given name of his own; functionally, the title of Supreme King is treated as his name. What's more, the series ultimately reveals that he isn't so much a true split personality as he is Judai simply embracing his worst aspects and the power of the Gentle Darkness, meaning that his "real name" is simply Judai. Of course, "Haou" does sound like it could be a name and "Supreme King" is rather clunky, which contributes to its use as a Fan Nickname even among fans who understand how the character works.
• Yu-Gi-Oh! 5Ds has some of the most persistent rumors in the franchise regarding its production, due in large part to the perception of Seasonal Rot owing to a controversial Retool in its second half.
  • A commonly-stated "fact" is that the character of Crow Hogan was rewritten from a primary antagonist to a tritagonist due to strong sales of his cards, against the wishes of the creators. This is basically impossible, since Crow had already debuted as a heroic character before his archetype ever hit the stands. What's more, Blackwings didn't become a truly meta deck until the release of Raging Battle expanded their lineup, which was well inside of the Dark Signer arc. He also plays no real role in most of the video games, which were directly made by Konami. It's true that he was rewritten from an early concept (Takahashi's character design envisioned him as a character who has tried to steal Yusei's D-Wheel countless times in the past, but is still "a hot-blooded friend of Yusei"), and that many of his plot points seem to have been rushed or altered in some manner, but it can't have been because of card sales—at least, not initially. When asked about the idea on Twitter, the creators claimed that Crow had been planned to be a Dark Signer at one point, but the idea was very quickly discarded, to the point that it came before Crow even had an actual name. Crow also reappeared in Yu-Gi-Oh! ARC-V, which had the same director, and he had a basically identical personality there (which was unique among reappearing characters), implying that the creators had no problem with making Crow a good guy—if anything, he seems to be something of a Creator's Pet.
    • The rumors about Crow have led to the similar idea that the various shows will introduce major characters with the specific intent of them showcasing highly dominant meta decks, with the other major candidate being Soulburner in Yu-Gi-Oh! VRAINS, whose Salamangreats won the 2019 World Championship. As the page for CCG Importance Dissonance can tell you, there are many, many cases of major characters with decks that were nonviable in the meta, and minor or Demoted to Extra characters with decks that were the Game-Breaker of their format. One need only look at the deck that won the prior year's World Championship, Trickstars—a deck whose user, Aoi Zaizen, lost big more often than she won, stayed Out of Focus for entire arcs, and ultimately swapped the deck out entirely. Meanwhile, Yusaku's pure generic-Cyberse deck was famously undefeated for the show's entire run, but was considered pretty much nonviable in the meta barring a handful of strong Links that saw use mostly in other decks. While Crow and Soulburner were both characters who came out of nowhere with incredibly dominant meta decks, they also seem to be the exception to the rule, and the franchise as a whole is no stranger to abruptly-important Sixth Ranger characters.
  • Many will claim that Aki being Demoted to Extra and made far less intimidating in the second half of the series owes to her voice actress having been pregnant during production. This is completely untrue; she wasn't even married at the time, and had her first child years after the show's conclusion. The second half of 5Ds as a whole didn't tend to give screentime to any of the prior characters aside from Yusei, Jack, and Crow; Aki being demoted only stood out because she was treated as the show's tritagonist in prior arcs, and even then, she was clearly a distant third in relevance to Jack and Yusei's rivalry.
  • There's a particularly common rumor that blames the show's shift in its second half to the Roma-Sophie sex cult scandal, which intensified further due to Carly's voice actress having been a prominent member of the cult. This is partially true, in that Carly's role was recasted, but this happened very late in the series, long after the series had thoroughly transitioned away from Urban Fantasy and towards science fiction. Additionally, Carly kept appearing for pretty much the entire series even after that transition, which doesn't line up with wanting to distance themselves from her actress. What's more, the series continued to use aspects of the old mythology and mysticism, albeit in a significantly reduced role (such as the appearance of Scar-Red Nova and Team Ragnarok), and the video games based an entire entry off the Arcadia Movement, the most cult-like entity in the series. Kazuki Takahashi explained in one interview that he conceived of many concepts in the Dark Signer arc, suggesting that the writers simply ran out of occult-oriented concepts and decided to focus on science fiction. It is perhaps worth noting that most accounts suggest that 5Ds generally underperformed in ratings in most territories, so the shift to a more kid-friendly and toyetic theme could simply have been an attempt to make the show more appealing. Carly, meanwhile, didn't truly become Demoted to Extra until later on in the arc (long after the shift to sci-fi was in full gear), suggesting that her lack of prominence had less to do with any kind of larger initiative and more the writers being uncertain of how to handle her relationship with Jack post-Dying Declaration of Love.
• Most people commonly assume that the factions seen in Yu-Gi-Oh! ARC-V are representative of their entire dimension, particularly in the case of the Xyz Dimension. Fans commonly assume and/or state that the Fusion Dimension has destroyed humanity in the Xyz Dimension, when in reality, it's only Heartland that has been attacked. The Synchro Dimension clarifies that only City is involved when Reiji calls out Roget on being satisfied with control over one city.
• In the United States, Yu-Gi-Oh! ZEXAL was aired on the Vortexx Saturday morning cartoon block on The CW network as typically the last show on the block at 11:30am. Therefore, it was dubbed as the last Saturday morning cartoon to air on broadcast television (since other broadcast networks have one way or another stopped airing animated cartoons on Saturday mornings in favor for more "educational and information" shows that tend to be live action) when Vortexx aired for the last time on September 27, 2014. However, this isn't exactly true, as NBC still had their NBC Kids block at the time of Vortexx's closure, which had animated programs from the Sprout channel. In that regard, the last Saturday morning cartoon was really Ruff-Ruff, Tweet and Dave as NBC Kids closed in September 2016.