The nameless hero is the protagonist of the Gothic franchise. Unlike in most RPG games, the hero's characteristics such as appearance, personality and attitude towards the world are pre-set (although the player still has large control over his decisions). In Gothic 1, the nameless hero is sentenced to a life of labor in the Valley of Mines and is given a letter, which he has to deliver to the Fire Mages who are trapped in the prison.
Though his crimes remain unclear, the nameless hero never argues his innocence and thus seeks to make his new life in the Valley of Mines. When the player chooses which camp to join (among the Sect Camp, the Old Camp, or the New Camp) ultimately the nameless hero is thrown into a conflict involving the Sleeper and his entrance into the Gothic world from beyond. He prevails, but at the cost of his own life.
In Gothic 2 the nameless hero is revived, only to be thrown into another struggle involving the elemental dragons, especially the great Undead Dragon. By Gothic 3, the nameless hero is prepared for the ultimate climax of the Gothic world. He can side with Beliar and the rule of all things dark and fearful, Innos, the god of goodness and honor, or serve his ally Xardas in ruling out all godly struggles throughout the world of Gothic.
In Forsaken Gods, it is assumed that the nameless hero sided with Xardas and must return once again, somewhat begrugingly, to save humanity from itself. By the end of the trilogy, the nameless hero has come from a lowly criminal to the most powerful man in the world of Gothic. He was sworn to be Rhobar III, king of Myrtana.
Arcania: A Gothic Tale no longer features the hero as the main protagonist, since he is the king. A new hero, also nameless (who is known only by a moniker of "the Shepherd of Feshyr") takes up his place as the player character. The new hero's village was apparently attacked by Rhobar's soldiers, and he remained the sole survivor of the whole ordeal. The new hero quests for vengeance and eventually finds out that there's more to the tyranny of the new, god-rejecting king than one may think. Apparently the tyrant is posessed by an ancient demon he struggled with a long time ago...