Dark Yugi and Seto Kaiba's school Duel

Yugi and Kaiba's school Duel was a Shadow Game of Duel Monsters in the Yu-Gi-Oh! manga and ''first series anime. This was Dark Yugi and Seto Kaiba's first Duel in these series.

This Duel used an early set of rules, which vary greatly from the Yu-Gi-Oh! Official and Trading Card Game.

While the events and turns are largely in both the manga and anime, an extra turn is added in the anime, where Kaiba causes the Duel to end in a Draw, while in the manga Dark Yugi won.

Prior events
Seto Kaiba got his eyes set on Sugoroku Mutou's "Blue-Eyes White Dragon" card after seeing it in Kame Game. Following an unsuccessful attempt to buy or trade for it, he made a counterfeit, which he tried switching with Sugoroku's when Yugi Mutou brought it to school.

Yugi approached Kaiba afterwards, saying he knew he took the card, but didn't want to say it front of everyone else and asked for it back. Kaiba denied taking it at first, but when Yugi persisted, he struck him with his briefcase. However Yugi switched to Dark Yugi and challenged Kaiba to a game of Duel Monsters.

Dark Yugi and Kaiba prepared to Duel in a classroom. Planning on making it a Shadow Game, Dark Yugi warned Kaiba that the rules of this game would be a bit different than what Kaiba is used to. Kaiba thought his Deck would be strong enough to win regardless of whatever house rules, but could still use the "Blue-Eyes White Dragon" and pretend to have gotten it elsewhere, should he get stuck.

The Duel
Kaiba Summoned "Ryu-Kishin" and was surprised to see the monster come to life.
 * Kaiba's turn

Dark Yugi Summoned "Blackland Fire Dragon" and used it to attack and destroy "Ryu-Kishin", dropping Kaiba's Life Points to 1500.
 * Dark Yugi's turn

Dark Yugi explained that this is a Shadow Game of Duel Monsters, where the cards the loser will know death as their Penalty Game. Kaiba replied that this was the extreme game he had been looking for and that he was glad he accepted the challenge.

Kaiba Summoned "Battle Ox". It attacked and destroyed "Blackland Fire Dragon", dropping Dark Yugi's Life Points to 1800.
 * Kaiba's turn

Dark Yugi Summoned "Mystical Elf" in Defense Mode.
 * Dark Yugi's turn

Kaiba switched "Battle Ox" to Defense Mode and Set "Giant's Might" to use next turn.
 * Kaiba's turn

Dark Yugi wondered what kind of card Kaiba Set and worried that if "Battle Ox" gets much stronger, he won't be able to stop it.

Dark Yugi drew "Skull Servant", which was too weak to help him.
 * Dark Yugi's turn

Kaiba activated "Giant's Might", equipping it to "Battle Ox", raising its ATK to 2040.
 * Kaiba's turn

"Battle Ox" attacked and destroyed and "Mystical Elf".

Over the next few turns, "Battle Ox" destroyed a number of Dark Yugi's monsters, including "Skull Servant", "Mushroom Man" and several unnamed, dropping Dark Yugi's Life Points to
 * Multiple turns

Dark Yugi Summoned "Summoned Skull" and Kaiba wondered how Yugi got such a card. In the Japanese version, Kaiba said it was one of the five strongest monsters in the game. In the English version, he said it was one of the five strongest Fiends.
 * Kaiba's turn

"Summoned Skull" attacked and destroyed "Battle Ox", dropping. Kaiba's Life Points to 1040 Life Points.

"Summoned Skull" destroyed a number of Kaiba's monsters, dropping his Life Points to 800.
 * Multiple turns

Although his Deck had cards that could beat "Summoned Skull", Kaiba thought that the odds of drawing one were low. However he thought that he could win using the "Blue-Eyes White Dragon" in his pocket.

Kaiba added "Blue-Eyes White Dragon" to his hand, pretending to draw it.
 * Kaiba's turn

Kaiba Summoned "Blue-Eyes White Dragon" and Dark Yugi declared that that was Sugoroku's card, but Kaiba insisted that it was his own copy.

Since "Blue-Eyes White Dragon" had 500 more ATK than "Summoned Skull", Kaiba planned on winning by attacking with it. However the "Blue-Eyes White Dragon" refused to attack as it loyalties were with Sugoroku. Instead it destroyed itself.

Dark Yugi used "Monster Reborn" to revive "Blue-Eyes White Dragon" and used it to attack Kaiba directly, dropping his Life Points to 0.
 * Dark Yugi's turn

Aftermath
Dark Yugi inflicted the Illusion of Death Penalty Game on Kaiba, causing Kaiba to believe his soul was trapped in a Duel Monsters card, causing him to be sent to the Duel Monsters Spirit World, where he experienced death at the hands of monsters.

Anime events
An extra turn is added where Kaiba Summoned "Gremlin" and used it to split the field in two, causing the Duel to end in a Draw.