The Duchy of Devinsmor is a 1st edition Advanced Dungeons & Dragons campaign established on September 29, 2018. Its players belong to a private club known as the Savannah Pendragon League and have been gaming together for decades. Among other things, the Duchy of Devinsmor is the home of the Dungeons of Dark Hammer Castle. The duchy is located within a Celtic-themed realm which also receives immigrants from nearby Norse and Sundarian lands (the latter being based upon the culture of feudal Japan).