Daemonic & Arcane is a collection of 25 strange pieces of magic (like the Scepter of King Robert the 1st or the Steps of Zayene) that were discovered by the players in the original Lake Geneva campaign from the early 1970s. The author, who was Gary Gygax's co-DM and shared responsibilities for developing the Castle Greyhawk megadungeon, also discusses how the items were created and in some cases what happened when the players encountered the bits of arcana.