Keep on the Shadowfell is the first official product from the 4th edition Dungeons & Dragons line. It is part one of a three-part series of adventures. The adventure, written by Mike Mearls and Bruce R. Cordell, was published in 2008 by Wizards of the Coast. The adventure is designed for characters from levels 1 to 3. Its module code, "H", stands for Heroic Tier. This module is set in the Nentir Vale.

An Introductory 4th Edition D&D Adventure for Characters of Levels 1st-3rd.

The town of Winterhaven stands watch over a ruined keep that was once a bastion of good in the realm. This keep overlooks the Shadow Rift, a dark scar in the world that was once a gateway to the Shadowfell but has been dormant for many years. Now, an evil cleric of Orcus, Demon Lord of the Undead, seeks to re-open the gate, and the only thing standing in his way is a small yet determined band of heroes.

"Keep on the Shadowfell" is the first published adventure using the 4th Edition DUNGEONS & DRAGONS® Roleplaying Game rules. In your role as Dungeon Master (DM), you get to send your friends on an adventure in which they'll explore dungeons, banter with villains, and defeat vicious monsters with sword, spell, and prayer. Together, the player characters (PCs) can work to thwart the insidious plot of an unholy cult, winning great treasure and a heroic reputation.

"Keep on the Shadowfell" is an exciting D&D adventure designed for characters of levels 1st–3rd. It includes three double-sided poster maps suitable for use with D&D Miniatures (not included).

This package also contains the "Quick-Start Rules" booklet for the 4th edition rules, which showcase an evolution in gameplay and puts an emphasis on fun. This booklet provides an overview of the game so that you can play the "Keep on the Shadowfell" adventure. These rules give only the most cursory explanation of the D&D® game. For the complete experience, including character creation and the full rules of the game, pick up the new D&D Player's Handbook book, Dungeon Master's Guide, and Monster Manual.

This adventure continues in H2 Thunderspire Labyrinth.