Monster Vault: Threats to the Nentir Vale presents statistics, tactics, and lore for an array of new monsters that prowl the Nentir Vale, some of which trace their origins back to the earliest editions of the Dungeons & Dragons Roleplaying Game. Other entries focus on campaign villains present in the Nentir Vale region, among them the Iron Circle, the Tigerclaw Barbarians, the Raven Roost Bandits, and several new villainous groups introduced here for the first time.

The monsters and villains contained within are appropriate challenges for heroic- and paragon-tier characters.