 Jacobs has authored and co-authored several other products for the "Dungeons & Dragons" fantasy roleplaying game, including "Dungeon Master's Guide II", "Lords of Madness", "Frostburn", and "Red Hand of Doom".He also wrote "" with fellow Paizo editor Erik Mona.Jacobs and Erik Mona co-wrote "Expedition to the Ruins of Greyhawk" (2007), a 3rd edition "D&D" remake of "Greyhawk Ruins" (1990).