[[quoteright:196:http://static.tvtropes.org/pmwiki/pub/images/ygogroupzero_4870.png]]
[[caption-width-right:196:Toei's version of the [[TitleDrop king of games]]! And HIS TrueCompanions]]

The first Franchise/YuGiOh anime series (also incorrectly known as [[FanNickname Season 0]]) was a 27-episode adaptation of the first seven volumes of the [[Manga/YuGiOh Yu-Gi-Oh! manga]], produced by Creator/ToeiAnimation. It loosely covers the story of Yugi completing the Millennium Puzzle up to the Monster World RPG arc of the manga. However, it skips many chapters of the manga in favor of filler episodes and re-introduces a one-shot character from the manga, Miho Nosaka, as a main character. Many chapters were reworked to fit the length of an entire episode and a number of the original games were either imported or replaced entirely. It also borrows plot elements that aren't introduced until Duelist Kingdom, such as the early introduction of Shizuka, Jonouchi's sister. Because of its lack of success, this adaptation was cancelled before it got to Duelist Kingdom. It was replaced by [[Anime/YuGiOh the second anime series]], which was made by Creator/StudioGallop and dubbed by Creator/FourKidsEntertainment.

It's a common misconception that this series was skipped by Creator/FourKidsEntertainment's dub for being too violent. Because the second series was done by a different studio and re-imagined some of the manga chapters that this anime also covered, Toei's Yu-Gi-Oh! is considered an alternate adaptation of the manga rather than a prequel to the second-series anime. It's also for this reason that this series was never [[NoExportForYou dubbed]] along with the second series anime, as it's a completely different license.

Some of this series' manga-to-anime alteration practices were carried over by the second studio when producing the second series anime, such as calling the "Magic & Wizards" card game "Duel Monsters." This series' incarnation of Seto Kaiba inspired the BigBad from a FillerArc of the [[Anime/YuGiOh second anime]], Noah Kaiba, whose outfit was inspired by Kaiba's Death-T outfit from the manga and had green hair, a ShoutOut to this Kaiba's green hair.

It spawned a 30-minute movie, a few video games and [[TabletopGame/YuGiOhCarddasVersion a card game created by Bandai]], which would later be replaced as well by [[TabletopGame/YuGiOh the newer card game]] by Konami.

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!!"Come... it's trope time!"

* AbandonedWarehouse: There's a warehouse for the yo-yo gang, the Capmon guy and the guy who plays with digital pets.
* AbusiveParents: Jounouchi's alcoholic father.
* AbortedArc: Because this adaptation was cancelled before it got to Duelist Kingdom, we never see Toei's version of Kaiba put together the last pieces of his shattered heart and become nicer.
* AdaptationDyeJob:
** Kaiba is depicted with bright green hair and gold eyes, in contrast to his dark brown hair and blue eyes in the manga. It's subverted in the movie where he has near golden-brown hair and light blue eyes, which is closer to his usual appearance.
** The school uniforms for the girls are more orange than pink, with green bows and skirts instead of blue.
** Bakura's hair is blue and he has green eyes (purple when Dark Bakura takes over), as opposed to his white hair in the manga.
** Shadi's eyes are amber as opposed to the dull blue in the manga.
** Aside from the anime-only height difference, Yugi/Dark Yugi's designs are largely the most manga-faithful designs in this anime. However, Yugi's eye color changes to red whenever he's taken over by Dark Yugi. While the colored manga covers and pages weren't exactly consist consistent with Yugi's eye color, Yugi and Dark Yugi's eyes were never depicted as being a different color from each other.
** Shizuka/Serenity's hair color was brown in the manga. In the anime, she has purple hair.
* AdaptationExpansion: Some of the battles from the manga get stretched out to fill a thirty minute time slot. Case in point, the tenth episode with [[SadistTeacher Ms. Chono.]] In the manga her story takes place entirely in the classroom and solely involves her solving the puzzle Honda left for Miho. In the anime, the puzzle aspect leads to Anzu formally protesting Chono's extreme rules and starts a petition, which Chono then sabotages by using some older students to steal it for her. The shadow game aspect turns into Dark Yugi challenging her to a jigsaw puzzle contest involving mirrors and blindfolds.
* AdaptationPersonalityChange:
** In the manga Honda was a tough guy who was VitriolicBestBuds with Jonouchi, while here he's a dorky hall monitor with a hopeless crush on Miho.
** Anzu in this series is a full-on Type B {{Tsundere}}. While Anzu in the manga could have quite a temper, it was never so frequent.
* AdaptationalEarlyAppearance: Ryou Bakura appears before Monster World, where he was introduced in the manga.
* AdaptationalHeroism: This Mokuba is more tame in comparison to his manga counterpart, not poisoning Joey or dueling Yugi in Capsule Monsters beforehand.
* AdaptationalVillainy:
** In the manga Ms. Chono was only interested in humiliation, but in the Toei series she's a sadistic control freak willing to go to extreme lengths to break Anzu's spirit just for questioning her authority.
** In the manga, Mr. Karita threatened to cut Bakura's hair. In the anime, he teases him about his friends from other schools going into comas and warns Yugi and his friends away from him.
** Seto Kaiba here is even worse than his manga counterpart. In this continuity, his butler, Daimon, is physically weak and lives in a life support capsule that he can only exit for a short amount of time. Kaiba wakes Daimon up, tells him to go fight Yugi (with Anzu as bait), tries to get him to cheat at Duel Monsters, and when he loses, Kaiba leaves him for dead right after Daimon expresses hope that his kindness can be restored. Then he goes on to build Death-T for the purpose of killing Yugi ''and'' his friends, not because of a Penalty Game and/or losing to Yugi, but because he ''tied'' with Yugi.
* AdaptationalWimp:
** Honda went from a tough guy in the manga to a rules-posturing student council member.
** In the manga, Jonouchi did very well in fights and was instrumental in winning Death-T. In this anime, he was the ''only'' one injured during Death-T 1 and Miho saved the day, was beaten up by Kaiba's guards and the model Aileen Rao, got beaten up by the Kageyama Sisters, and rolled a 99 in Monster World out of fear that he'd be turned into a figurine.
* AdultFear: Episode 11 has Miho deal with a creepy stalker who wants to imprison her inside a giant Capmon capsule. Miho is about 15 and her stalker is at least 18.
* AlphaBitch: Kaoruko Himekoji tries to sabotage Anzu and Miho in a popularity contest by sabotaging Anzu's acts, destroying Miho's clothes, and when that doesn't work she ''drugs'' Miho, tears up her clothing, and leaves her in an alley.
* AmusementParkOfDoom: Death-T.
* AscendedExtra: Miho Nosaka was only used in one chapter in the manga as a love interest to Honda (who promptly shot him down when he asked to be her boyfriend). She was used more in the anime to help fill out the girl quota, though at best she's a SatelliteCharacter.
* AxCrazy: Dark Yugi can become this if you make him mad enough.
** Dark Bakura is also this, especially when he starts losing.
* BelievingTheirOwnLies: An early PhonyPsychic enemy of the week.
* BewareTheNiceOnes: Ryou Bakura is a very sweet, shy, quiet, polite guy with a SuperpoweredEvilSide that he's only vaguely aware exists.
** The same goes for Yugi. He is nice and weak, until his psychotic side wakes up.
* BitchInSheepsClothing: Kaiba pretends to befriend Yugi and has Yugi's grandfather's Blue Eyes White Dragon switched with a copy. When Yugi figures this out and calls out Kaiba on the switch, Kaiba loses the facade and whacks Yugi in the face with a briefcase.
* BoardGames: Capsule Monster Chess. Unlike the manga, it isn't introduced as Mokuba's favorite game until Death-T; instead it's introduced with a filler character in a completely different plotline.
* {{Bowdlerise}}: Many of the death-related Penalty Games were turned into illusions, and several storylines were made less violent and disturbing. The most notable altered storyline is Death-T, which replaces the chainsaw-wielding Chopman with a huge robot. Kaiba's butler dying from electrocution is also removed, as was Honda's breast-grabbing perverted baby nephew.
* CardGames: Duel Monsters plays a large part in all arcs concerning Kaiba.
* CherryTapping: Dark Yugi tends to win his Shadow Games this way, even making a hole in one with a ''stethoscope'' against a {{Jerkass}} doctor in episode 16.
* ClockPunk: The Shadow Game between Yugi and a collector/thief of rare watches takes place around a huge clock pendulum.
* ColorWash: Toei's anime has an incredibly supersaturated neon palette.
* ConspicuousCGI: The first series had this a few times, such as in the opening, or in episode 6 with the stairs.
* CompressedAdaptation: Only a handful of chapters from the first seven volumes of the manga were animated. In comparison, a lot more chapters from the manga were left out than there were animated, making the anime significantly shorter than the manga even if you don't count Volume 8 onwards.
* DeathTrap: Kaiba's sadistic amusement park, Death-T, is a long series of increasingly difficult death traps designed to defeat and kill Yugi.
* DisproportionateRetribution: Kaiba and Yugi’s first duel is changed into a draw, so neither side wins and he doesn't get a penalty game. Kaiba becomes ''so furious'' at the duel ending in a draw that he sends his Game Masters to kill/defeat Yugi and his friends, stalks Yugi to see if anyone else is trying to beat him in a duel first, and builds Death-T for the purpose of killing Yugi and his friends.
* TheDitz: Miho is very spacey most of the time and usually is the last to realize things are dangerous.
* EarlyInstallmentWeirdness: A series about a weak boy whose darker side wakes up to brutally punish those who inflicted pain to him by using magic totally sounds like a series about a children's card game.
* EvasiveFightThreadEpisode: Yugi and Kaiba's first duel is reworked into a draw, so neither side wins.
* EvenEvilHasStandards: Yami Yugi isn't evil per say, but he's not a pure hero either. He does put his foot down when something doesn't sit right with him.
** Yami Yugi may have rigged his mind so that Shadi wouldn't find his true room, but he wasn't about to let the man die.
** When Mokuba is put through Kaiba's penalty game, Yami Yugi pulls him out before the illusions take full effect on his fragile mind.
* EvilCounterpart: The Millennium Ring/Dark Bakura to the Millennium Puzzle/Dark Yugi.
* ExcitedTitleTwoPartEpisodeName: "Desperate Situation! Passionate Battle for Friendship" and its ilk are quite a mouthful. The format varies, but titles usually follow the Excited Exclamation! More Calm Description of Events format.
* FightingSeries: Using games. Though Jonouchi plays a live-action fighting game during Death-T using Power Suits.
* GottaCatchEmAll: Yugi's Grandpa says that Capsule Monsters was not a collection game, but the epitome of a fighting game. Dark Yugi later echoed this in delivering his LaserGuidedKarma.
** Dark Bakura collects the souls of his victims as miniatures.
* GracefulLoser: Aileen Rao accepts defeat well, releasing Anzu as promised.
* HumansAreBastards: Ooooh, very much so. Yugi can't even go to the arcade with his friends for a good time, without being beaten up by some random asshole who rages over the fact he lost a video game, [[SoreLoser and blames innocent bystander Yugi for the loss]].
* KillerGameMaster: Dark Bakura. Tabletop {{Role Playing Game}}s are supposed to be adventurous, not scary.
* KingOfGames: TropeNamer; it's the title the main protagonist has for his mastery of gaming.
* LeftHanging: The anime ends after the Monster World arc and never got around to doing any other chapters. Individual episodes tend to end this way due to a rushed climax, such as the Kageyama sisters never getting punished since the episode ends right after Kaiba defeats them or Yami Yugi just leaving after explaining the Mind Crush to Mokuba.
* LighterAndSofter: Compared to the manga.
* TheManBehindTheMan: In the virtual pet episode, it's revealed that the timid Haiyama boy that Yugi befriended before was ''controlling'' the large Kujimoro guy. What's worse was that he was treating him ''like a pet''.
* MindRape: Most of the manga's death Penalty Games were replaced with illusions.
* MundaneMadeAwesome: Hirutani and his gang's weaponry revolves exclusively around yo-yos.
* NonSerialMovie: Toei made a 30 minute movie after the cancellation of the anime. It features the same voice actors that appeared in this series and features the same songs, but the character designs are more accurate to the manga. The plot aspects of this movie are rather contradictory to its own anime. Bakura isn't present, Kaiba seems to be relatively "normal" and awake even though he's supposed to be suffering from the aftereffects of Mind Crush and in a coma, Yugi and Kaiba use the first version of the Duel Disks which aren't introduced at this point, etc. It could take place after this anime's equivalent of Duelist Kingdom [[CrypticBackgroundReference that never aired]], but Jonouchi doesn't recognize the Red-Eyes Black Dragon (it's treated as some legendary card) and Saruwatari still works for Kaiba.
* OhCrap: The default reaction to Dark Yugi's Shadow Game victims. Dark Bakura has an OhCrap moment when he realizes the real Bakura regained control of his left hand.
* TheOnlyOneAllowedToDefeatYou: Kaiba stalks Yugi for an entire episode because he suspects someone ''else'' is trying to defeat him in a duel and refers to his rival as bound by the red string of fate.
* RealityWarper: A major difference between this and the manga/second series anime is that the Puzzle seems to give Dark Yugi reality-warping powers. In contrast to the manga where Dark Yugi challenges Ushio to a knife game on the spot, Dark Yugi in this anime transports Ushio (by surprise, who was walking home) to a tower, tied to a rope which appears out of nowhere. Dark Yugi also seems to make the [[ArtisticLicensePhysics playing cards stay in place on the wall]]. And in the "watch thief" episode, he transports the watch to a dimension of clock gears and in general can conjure up anything needed for his Shadow Games.
* RedEyesTakeWarning: Dark Yugi has red eyes in this series and this is played straight for anyone who harms Yugi.
* SparedByTheAdaptation: Most of the characters in the anime are spared from their particularly nasty demises, especially Prisoner 777 who was ''burned alive'' in the manga and was given a MindRape Penalty Game in the anime.
** Gozaburo Kaiba is alive in the present day, though it's implied he dies via heart attack when Kaiba cements control over [=KaibaCorp=] in episode 20.
* StalkerWithACrush: Warashibe seems to be this for Miho. However, his strange obsession with Capumon and her merged and he becomes a {{Yandere}}, determined to claim her by any means necessary.
* StalkerWithoutACrush: Kaiba is so determined to beat Yugi that he follows him around town, waiting to jump him.
* TwoGirlsToATeam: Due to Miho being upgraded to a main character from her one-off status in the manga, she and Anzu are the main female characters.
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