 Reviews of Mask of the Betrayer were generally favorable . Obsidian Entertainment 's handling of epic levels in the expansion was particularly praised , although some reviewers said that at higher levels the expansion became unbalanced . A number of reviewers mentioned that the expansion allows for more customization of both characters and levels , with Game Informer saying that " Piles of new feats , spells , and classes will give even seasoned D & D vets plenty to explore , either in the official campaign or custom scenarios built by the community . Likewise , builders can benefit from the ever @-@ improving toolset and ( supposedly ) fixed persistent @-@ world implementation . " Eurogamer also described the new classes , prestige classes , and races as " pretty damn neat " . Eurogamer stated that starting Neverwinter Nights 2 over from the beginning after installing Mask of the Betrayer is also interesting because the expansion " integrate [ s ] with the previous game ( i.e. you can select one of the new races and classes and go back and play NWN2 with them ) " . 
