Obelisk Blue is the highest of the three dormitories at Duel Academy. The reason for its superiority over the other two dorms goes back to the fact Seto Kaiba is the owner of this school and that he possessed "Obelisk the Tormentor" during Battle City.

While Obelisk Blue is considered to be the dorm with the best students although this is not necessarily true as Jaden Yuki is known as the school's top ranked duelist. The dorm is mostly made up of students who have connections and are rich. Luxurious interior design, high-quality rooming, and finer food are offered to the students who reside here. In order to enter Obelisk Blue, one needs to have high grades. In order to start in Obelisk Blue upon enrollment, not only does one needs to have high grades in the written examination but they also need to have earned a diploma from another duelist prep school. The dormitories are divided into separate sections based on gender. Dr. Crowler is in charge of the male dorms while Fonda Fontaine is in charge of the female dorms. Contrary to popular belief, all female students that are accepted into Duel Academy are automatically placed in the Obelisk Blue dorms regardless of whether they have the skill necessary to have been accepted into dorm, with the exception of Blair Flannigan who entered the Slifer Red dorms in a separate manner than the traditional entrance exams. The reason for this is because the lower two dorms do not have the appropriate housing as Obelisk Blue is the only one with separate dormitories for both female and male students. For example, Alexis's two friends have been shown to have skills below what is expected of their dorm. There is a running gag throughout the series where the characters of Obelisk Blue keep disappearing or transferring out of the dorm despite the fact it's valued as the place all the students want to be. This is seen with the creation of the Obelisk White and the constant dorm rearrangement of Chazz Princeton.