When an Obelisk Blue upperclassman get jealous seeing Jaden talking with Alexis, he gets jealous and challenges Jaden to a duel and the winner becomes Alexis' fiancé.
- Compete for the Maiden's Hand: The high school version.
- Green-Eyed Monster: Harrington gets jealous when Alexis ignores him to talk to Jaden, starting the duel with him due to believing he was giving him competition for Alexis.
- Hoist by His Own Petard: Due to the effect of The Big Server, Jaden is allowed to draw a card from his deck after it inflicts battle damage to him. The card he drew happens to be Feather Shot, and Jaden uses this card next turn to win. Jaden even lampshades this when he explains when he drew the card to Harrington and reminds him of what Harrington said when he drew it.Jaden: I drew this card when you activated The Big Server's special effect. Remember what you said?
Harrington: (flashback) You get a new card too, but it won't matter.
Jaden: Yeah, well guess what? IT MATTERED! - Informed Attribute: Harrington is stated to be as good as Zane, but from what we've seen of his deck, Jaden was mostly backed into a corner out of bad luck. His cards are either luck based (Service Ace requires Jaden to guess between monster, spell, or trap and takes damage if he's wrong, while Smash Ace requires the top card of his deck to be a monster), situational (Deuce requires both players to have 1000 life points) and his monsters we see him possess are weak low level monsters. The only genuinely useful cards we see are Big Server who can attack directly, Giant Racket which can protect the equipped monster once per turn and negating any battle damage to the user, and Receive Ace which can negate an attack and inflict 1500 points of damage at the cost of sending the top three cards of his deck to the graveyard. That said, it should be noted that him being as good as Zane was just a rumour, and rumours, especially school ones, tend to be greatly exaggerated at best and complete lies at worst.
- I've Heard of That — What Is It?: After Jaden wins the duel against Harrington, he approaches Alexis and comments that he guesses he's her fiancé now, before asking what a fiancé even is. While Syrus, Jasmine, and Mindy are all annoyed by this, Alexis just says it means "friend", before adding "at least for now, big guy". In the Japanese version, she simply calls him an idiot.
- Loophole Abuse: Harrington's Deuce spell declares a winner when a duelist is able to hit their opponent twice without interruptions and only one monster can be used per turn. Jaden uses his Feather Shot spell allowing Avian to attack the same amount of times as Jaden has monsters on the field. With three monsters, Avian is able to attack 3 times. The first to deflect Big Server's Giant Racket and the other 2 to destroy Big Server and attack Harrington directly. With Jaden getting 2 hits on the same turn, he wins.
- Misplaced Retribution: Even though Jaden wasn't the one who hit Crowler, he still gets punished on the grounds that he was the one who started the whole thing. To add insult to injury, Harrington, who did hit Crowler, gets to be the one who bosses Jaden around for the day. Syrus quite accurately calls this "the most unfair thing ever."
- Mistaken for Romance: Harrington mistakes Alexis and Jaden for a couple, or at least Jaden as a romantic rival, even though it's apparently never occurred to him to see Alexis that way.
- Reasonable Authority Figure: Fontaine, who points out that Jaden wasn't actually the one who hit Crowler and tries to get Crowler to forgive him. Unfortunately for her, Crowler isn't willing to listen.
- Unishment: Subverted. Jaden suggests to Crowler that to avoid causing another case where the latter gets hit in the face, he simply quits tennis since he doesn't even like it. Naturally, Crowler latches on to this and forces Jaden to join the school's tennis club for one day as his punishment.
- When All You Have Is a Hammer…: Lampshaded in the Japanese version. Judai (Jaden) notes that Ayanokoji's (Harrington) duelling style is very formulaic, consisting almost entirely of playing Spells or Traps that cause damage to the opponent. To his credit, Ayanokoji doesn't deny this, but states that it's just how he duels.
