This is City-State of the Invincible Overlord (1976), the first product from Judges Guild and one of the first forays into campaign world design to hit the market at an affordable price.

What we now consider a full product is actually a collection of several items that debuted as installments for JG’s subscription service. You have the massive map, printed in four 17×22 sections, the 17×22 player’s map, an 11×17 map of a dwarven stronghold, ten dungeon maps and three booklets – one detailing pretty much every building in the city, the others collecting tables for rumors, encounters and house rules. Later editions would consolidate everything but the large maps into an 80-page book (I have both the original modular version and the compilation – the illustrations reproduced here are all from the later edition, the maps and the cover are from the original). This is a truly unprecedented amount of campaign material for 1976.

Bonus: it is all really high quality. There are endless taverns, inns, shops, temples and NPCs described. The city is a brutal, crime infested place, ruled over by a powerful tyrant. It is a ridiculous place, with many factions that shouldn’t co-exist doing so peacefully (shades of Planescape), because of the Overlord’s power. His entourage also emphasizes this – he has beholders and mind flayers on staff – but also invites players to attempt to overthrow him.

All the detail is super lean, of course, a line of text with some stats for any given item of interest, usually, but the total forms a vivid, slightly bonkers place begging for exploration and wild schemes. It’s fantastic, really (and, judging from later re-imaginings, hard to reproduce – modern polish obscures this raw vigor). City-State was a huge success, and Judges Guild would go on to expand the world around it, creating one of the most popular (and influential) campaign settings of the early days of RPGs.