Jerry's Map: a 60-year imaginary city built by an algorithm of cards

What began in 1963 as a bored office worker’s doodle has become a sprawling generative-art system. Jerry’s Map is an imaginary city rendered across more than 4,000 hand-made 8x10 panels that assemble into a rough circle, with each panel’s position fixed by compass coordinates radiating from the center. The panels themselves are never finished — they’re continually overwritten in new layers using acrylic, marker, collage, lumen prints, and inkjet output. Shelved in an attic in 1983 and revived years later when his son found it, the project now runs as an ongoing procedural ruleset rather than a static drawing.

The engine driving it is a custom deck of roughly 100 cards. What started as a crude random-number generator (draw a card, skip that many panels) evolved into a programmable instruction set: cards dictate work direction (red counter-clockwise, black clockwise), how many one-inch squares to fill, whether to seed a new panel, mix paint, screen-print neighbors, or even modify the deck itself by adding, retiring, or renumbering other cards. The deck is self-mutating and includes meta-tasks like logging to a blog, posting to Reddit, or recalculating the set’s eBay resale value. There’s also a defined role for an ‘Artist’s Helper’ who scans panels into a digital library, archives retired work, and maintains inventory.

The interesting part for a technical reader is that this is essentially a hand-executed program with deterministic rules, mutable state, and a randomness source, producing emergent output its own author treats as something he observes rather than authors. The city advances through formalized layers — base phases, the Void, the Red Dimension, Black Ness, the unrealized Ziggurat and Flood — like state transitions that may never all execute. It’s a decades-long study in how simple rules plus controlled randomness generate complexity, and it has spawned a small community (r/jerrymapping) replicating the method.