The Duel Computer (ﾃﾞｭｴﾙｺﾝﾋﾟｭｰﾀｰ Dyueru Konpyūtā), also known as the Duel Machine (決闘マシーン) in the in the Japanese version, is a computer used by Seto Kaiba to practice dueling against. It appears in the anime when Kaiba tests his new Duel Disks and "Obelisk the Tormentor". Giving the computer his old deck, he defeats it using "Obelisk". Due to the excessive power of "Obelisk", the computer overloaded and exploded.