This deluxe adventure takes heroes into the ruins of Gardmore Abbey, a monastery that was once the base of a militant order of paladins devoted to Bahamut. According to legend, the paladins brought a dark artifact back from a far crusade and stored it in their abbey for safekeeping, and evil forces gathered to assault the abbey and take it back. What the legends don’t tell is that this artifact was actually the Deck of Many Things, a force of pure Chaos.
This adventure brings characters into the extensive dungeons beneath the ruins - dungeons that are warped and twisted with the raw forces of Chaos surrounding the cards of the deck.The first two super-adventures for D&D 4e — Revenge of the Giants (2009) and Tomb of Horrors (2010) — were both published as 160-page hardcovers. But then Essentials (2010) happened and afterward Wizards of the Coast totally revamped their 4e line. Madness at Gardmore Abbey was thus published as a boxed set. It contained four 32-page booklets and a variety of other doodads.
Because it was a boxed set, Madness at Gardmore Abbey was able to include a variety of components. Some of them showed the directions that D&D was moving in at the time: a sheet of Dungeon Tiles could be used with the many sets that Wizards was then producing, while new monster tokens were meant to be used with the ones recently released in the Essentials Monster Vault (2010).However the most interesting component in Madness at Gardmore Abbey was surely its Deck of Many Things, a physical deck of 22 cards that revealed one of the oldest artifacts in the D&D game.
Madness at Gardmore Abbey is set firmly in the Points of Light world that was growing increasingly detailed in the late days of D&D 4e. The abbey itself lies near Winterhaven — a local that appeared in the first 4e publication, H1 Keep on the Shadowfell (2008), and which also gets some detail here.
Madness also touches on the past of the Points of Light world, by detailing a fallen Point of Light — and so focusing on the core ideals of the 4e setting. Townshend says that his intent was to "evoke a sense of awe and of loss" by carefully revealing what was now gone, something that he was able to expand upon when he wrote "The Siege of Gardmore Abbey".
Finally, Madness ties lightly into the World Axis, with connections to the ever-popular Feywild and to the Far Realm.