Collector's cards
Konami's Yu-Gi-Oh! Duel Monsters is a collection of 20 Holofoil Rare promotional cards released in two sets of ten cards each, the Yu-Gi-Oh! Monster Capsule: Breed and Battle promotional cards and GameBoy Duel Monsters Promos: Series 1. As these cards all predate the introduction of the Official Card Game and use a different design, they are illegal for tournament play.
The collection consists of 17 Monster Cards and three Spell Cards. The monsters only have a Level, ATK, and DEF, and the Spells feature only an effect.