Geoff is a fictional land that is part of the Dungeons & Dragons role-playing game. Geoff was first described in 1983 in the World of Greyhawk campaign setting, where Geoff is properly known as the Grand Duchy of Geoff, and is a ducal political state of the fictional continent called the Flanaess.
Besides being in literature and serving as a potential land of adventure for players of the Dungeons and Dragons campaign, the Grand Duchy of Geoff was selected by The RPGA and Wizards of the Coast as a region for its Living Greyhawk campaign (2000–2008). As a result, thousands of role-players enjoyed adventures and other gaming events held in Geoff.
As described in the original World of Greyhawk Fantasy World Setting, the Duchy of Geoff was at peace and safe from the ravages of war that threatened the continent. Later published boxed sets and supplements such as From the Ashes, Greyhawk Wars, Against the Giants: The Liberation of Geoff, and the Living Greyhawk Gazetteer described how the region was transformed in Common Year (CY) 583 / Flan Tracking (FT) 2463 as armies of giants from the Crystalmist Mountains mounted a brutal invasion. Much of the Duchy was destroyed or enslaved.
Geoff is situated in the western Sheldomar Valley region of the Flanaess. The nation is bordered by the Crystalmists to the west, the Barrier Peaks to the north, the Stark Mounds to the south, and the Javan River to the east. Its closest neighbors are the Valley of the Mage to the north, Gran March to the east, and Sterich to the south. Geoff encompasses the entire Hornwood, most of the Oytwood, and the western portion of the Dim Forest.