Yu-Gi-Oh! is a subseries of the English Yu-Gi-Oh! manga. It occurs prior to the plot shifting to mainly Duel Monsters-centered storylines.
It covers chapters 1 to 59 of the manga, which are compiled in volumes 1 to 7. After this, numbering in the English manga was reset to 1 and the series continued as Yu-Gi-Oh! Duelist; the Japanese version did not reset numbering or split the series into subseries.
It contains the "Trial of the Mind", "Death-T" and "Monster World" arcs and a number of standalone chapters, almost all of which each contain a different game.