Yuugi is your everyday kid that has a passion for games. He lives with his Grandfather at a game store where he learns how to play several different strategy games. He often gets bullied for being the shortest kid in class and is almost always alone. Until one day, he solves the Sennen Puzzle, awakening the spirit residing in it, Yami No Yuugi.
Yuugi's deck is practically his grandfather's deck until much later on in the series. In episodes 220-224 and during his duel with Yami Bakura, he has his own deck basically made of magicians, spellcasters, and machines.