In Neverwinter Nights 2: Mask of the Betrayer, players are transported back to the Forgotten Realms shortly after the events detailed in the original Neverwinter Nights 2. Following the climactic battle against the King of Shadows, the player awakens alone and stranded deep beneath the earth. Surrounded by a horde of evil spirits, the player embarks on an epic adventure that reveals his true destiny.

Set in harsh, spirit-rich Rashemen, near the powerful nation of Thay, Neverwinter Nights 2: Mask of the Betrayer will present players with an exciting new campaign; epic levels; dozens of new feats and spells; new races, base classes and prestige classes; new companions; new weapons, armour and crafting options; hordes of new monsters; and enhanced modding tools.