Yu-Gi-Oh! Duel Monsters is the second Yu-Gi-Oh! video game, following Yu-Gi-Oh! Monster Capsule: Breed and Battle. It is the first game in the Duel Monsters series and the only game released for the Game Boy. The player must defeat each character in a stage five times to advance to the next stage. A character that has been defeated five times can be Dueled additional times for more cards.