Yu-Gi-Oh! The Eternal Duelist Soul is a Yu-Gi-Oh! video game for the Game Boy Advance. Gameplay is similar to standard dueling rules, except that the Side Deck allows less than 15 cards, and is more for convenience of getting to cards for your Deck than switching between duels, as CPU duels are single duels rather than matches (with some exceptions in events). Source: Yu-Gi-Oh! Wikia, "Yu-Gi-Oh! The Eternal Duelist Soul", available under the CC-BY-SA License.