The City-State of the Invincible Overlord was the first fantasy RPG setting ever published (1976). It features a huge walled city that is ruled by the eponymous (lawful evil) Overlord and the surrounding environs that are full of adventure possibilities. What was so striking at the time that it was first released was the incredible level of detail that the product contains. Hundreds of streets are mapped, named, and populated with shops, temples, inns, taverns, brothels, houses, barracks, and the like. Hundreds of NPCs are listed along with their stats and rumors they know (for starting adventures). The history and political system of the City State is described along with relevant laws the PC's must abide by while inside the city. It includes dungeon levels beneath the City State and detailed information for nearby adventure / dungeon sites: the dwarven fortress "Thunderhold" and the "Sunstone Caverns".
The City State was designed for Dungeons & Dragons (Original Edition) but was not officially licensed for D&D until 1978. The license ended in 1983. It was printed many times over the life of Judges Guild and changed in size and configuration in subsequent editions.
The first "edition" was spread out across several different publications / releases throughout 1976:
- City State Map: A 34" x 44" map of the City State
- Initial Guidelines Booklet I: A 16-page booklet with charts, rules and background data for the City State such as NPCs, crimes and trials, etc.
- City State Player's Map: A 17" x 22" map of the City State (originally printed on four 8.5" x 11" sheets) that was blank inside for players to fill in details as they explored the city
- Dungeon Level Maps I 1-5: Five dungeon levels beneath the City State
- Guide to the City State: A 56-page booklet detailing hundreds of shopkeepers and other NPC's, background information, special buildings, and additional rules for running campaigns in the City State
- Thunderhold & Sunstone Caverns Maps: 11" x 17" map with the dwarven fortress on one side and the caverns on the other
- Initial Guidelines Booklet J: A 12-page booklet with additional charts, rules and background data for Thunderhold and Sunstone Caverns
- Dungeon Level Maps J: Four dungeon levels beneath Thunderhold
In 1977 the above items were bundled together into one heat-sealed baggie with a cover sheet entitled City State of the Invincible Overlord.
In 1978, Judges Guild compiled and edited all of the information from the various booklets into one 80-page book and released it as a "Revised Edition". Included in this release were two 22.5" x 28.5" maps of the City State (judge, player), an 11" x 17" judge's map of Thunderhold/Sunstone Caverns, and an 8.5" x 11" player's map of Thunderhold/Sunstone Caverns. This configuration was reprinted, potentially with minor edits, in 1979 and 1980.
- In 1981 the Thunderhold/Sunstone Cavern maps were incorporated into the main book, which grew to 96 pages to incorporate a new layout and illustrations.
- In 1983 the cover was changed to remove the "Approved for use with Dungeons & Dragons" claim.
- In 1999 the product was reprinted, nearly identical to the 1981/1983 printings, but with a blue cover and updated "Booty List" (product listing) in the back.