Duel Academy, known as Duel Academia in the Japanese version, is the setting of most of Yu-Gi-Oh! GX. It is a dedicated school that trains Duelists to a professional level, so they can ideally enter the Pro League. It has three dormitories: Slifer Red, Ra Yellow, and Obelisk Blue. Students there usually wear blazers that match their dorm color. It is owned by Seto Kaiba.
Students also carry PDA-like devices on their person. The devices are used for communication between teachers and other students, like a video cell phone or e-mail. They are also used for digitized duels between users.
Simply referred to as Duel Academy, this branch was created by Seto Kaiba, who also designed the rank structure of the students. The Central Academy is located on an Island with a dock for boats, a volcano, beach and a lake, cliffs and waterfalls. It has the Main Academy Building where the students go to learn how to duel, with a gym building (separated from the main building) located beyond the beach. It has five dormitories, one of which is abandoned.
The four Dorm Buildings that house the Students are separated into ranks, with the low-end duelists in the Slifer Red Dorm, the middle-ground duelists in the Ra Yellow Dorm, and the high-ranked duelists in the Obelisk Blue Dorm. (Blue is the only Dorm shown to be separated into two buildings -- one for male students and one for female students.)
The Dorms were separated into three groups based upon Seto's perceptions of the people who originally had the 3 Egyptian Gods. The students originally used silver Duel Disks until the fourth season of Yu-Gi-Oh! GX in which each student's silver Duel Disk was replaced with a Disk that matched the color of the Dorm of that duelist.
- Slifer Red (Osiris Red) is where the low-level Duelists are housed. It was named after the Egyptian God Card "Slifer the Sky Dragon" which was originally owned by Yugi Muto, whom Kaiba felt bitter towards because he lost to Yugi time and time again. The students of this dorm wear Red Jackets and used Red Duel Disks to match the colors of their Dorm. The main students in this dorm also tend to bear a similarity to Yugi: they are very determined and nearly always pull through.
- Ra Yellow is where the average-level Duelists are housed. It was named after the Egyptian God Card "The Winged Dragon of Ra "which was originally owned by Marik Ishtar, whom Kaiba didn't care much for. The students of this dorm wear Yellow Jackets and used Yellow Duel Disks to match the colors of their Dorm. The featured students in this dorm are smart and cunning which was one of Marik's defining traits.
- Obelisk Blue is named after the Egyptian God Card "Obelisk the Tormentor" which was originally owned by Kaiba himself and therefore chosen to house the most skilled Duelists. They wear Blue Jackets and used Blue Duel Disks to match their Dorm colors. Chazz resembles Kaiba in that he considers himself to be a superior duelist.
- Obelisk White was a temporary dorm that existed when the Society of Light invaded Duel Academy. Chancellor Sheppard allowed this dorm to become official, the attire for those who "joined" them is similar to that of the Obelisk Blue uniform for males and females; the only difference is the alteration in colors from a royal blue and white design to a white and lavender design.
Many characters who no longer attend Duel Academy (such as Aster Phoenix and Zane Truesdale) continue to use the silver style Academy Duel Disk. The change is cosmetic only and the Disks still retain the exact functionality of the original Academy Duel Disks.
In November 2007, a real-world version of the red-trimmed Slifer Red disk was also produced in Japan, known as Academy Duel Disk Osiris Red and came boxed with several Booster Packs and promotional cards.