Shadows of Undrentide
The Shadows of Undrentide is an adventure featuring all-new skills and feats with which the player's characters may grow, as well as five new prestige classes. For this reason, Shadows of Undrentide has been created as a campaign that works best starting with a new 1st-level character. However, players who prefer to use a pre-existing character may do so.
Hordes of the Underdark
Hordes of the Underdark is an adventure featuring all-new skills and feats with which the player's characters may grow and even achieve epic levels. Hordes requires a high-level character; the Underdark is not the place for fledgling adventurers. Either continue a character from Shadows of Undrentide or the original NWN story or choose a pre-made character. If the character enters the game with fewer than 12 levels, the player will be given the choice to automatically level all the way to level 15 or manually level up. Characters of level 12 or highter are allowed to play, though the higher the character's level, the less difficult they will find the challenges in Hordes of the Underdark.
- Chronologically, the story line in SoU occurs at the same time as the original campaign's plot.
- Some non-player characters in HotU will assume the player's character went through Shadows of Undrentide; they may refer to events in SoU.
- There is also the Community Expansion Pack (CEP), which is free content and not sold for profit as SoU and HotU are. SoU and HotU both contain modules that are designed to be playable, while CEP only contains a module whose purpose is to demonstrate the objects contained within it. CEP is not really an "expansion pack" in that sense.