The City-State of the Invincible Overlord was the first published fantasy role-playing game city setting, designed for use with Dungeons & Dragons, and officially approved for use with Dungeons & Dragons from 1976 through 1983. Published by Judges Guild and later under license by Necromancer Games, the City-State of the Invincible Overlord was first released at Gen Con IX in 1976.
City-State of the Invincible Overlord was designed by Bob Bledsaw with the assistance of Owen, and was based on Bledsaw's own Dungeons & Dragons campaign.
The City-State launched Judges Guild as a company, and was the centerpiece of its Wilderlands of High Fantasy campaign setting, the first licensed and published Dungeons & Dragons campaign setting.
The City-State itself was a single city designed to be both as a base for campaigning, as well as a seed for city-based adventures. A second product, Wraith Overlord, explored the city's subterranean cellars, sewers and catacombs.
The City-State was used as a home-base for characters created by Judges Guild in other products. Attention was also paid to synchronising the City-State with broader adventure possibilities: a northern Dwarven fortress city Thunderhold with an associated "dungeon" area; and a series of four modules written to explore areas adjacent to the route from the City-State to Thunderhold, as well as a fifth which was to introduce a "witch" NPC character class.
The City-State has gone through several editions: