Yu-Gi-Oh! Duel Monsters 4: Battle of Great Duelist is a Japan only Yu-Gi-Oh video game for the Game Boy Color, and the fourth installment in the Duel Monsters series. It was released December 7, 2000 as three separate versions (Yugi, Kaiba, and Jounouchi), each being able to use only a certain selection of the 900 available cards.