Atlas Table

A table for fantasy maps that a small group shapes together, live. Raise mountains, paint forests, set down villages, draw walls and roads, and send a link: everyone with it sees each change within a second. No account is needed.

Try it

• Home (/): a world is generated for you; Create this world makes it yours.
• Editor: Land, Terrain and Water shape the map, and Places sets down buildings, walls, palisades and roads. Chart is a flat map; Relief is the same map in 3D. Share gives an edit link and a view link.
• The shared world (/world/) is open to anyone; try it in two browsers.

What "good" means here

Good means a small group can build a world together in real time, and enjoy doing it. That needs four things at once:

1. Real collaboration. You see who is here and each change as it lands. Undo only takes back your own work, and never overwrites a collaborator's newer edit.
2. A result that looks like a map. Painted cartography in the style of Inkarnate and Wonderdraft, not a tile grid or icons on a picture. My first version only let visitors drop marks on a fixed island picture, so I replaced it.
3. Freedom to shape the world. The map itself is what you edit: coastlines, seas, mountains, forests, towns and roads, not a fixed backdrop.
4. Controls that stay out of the way. A short tour, multi-step undo, walls that snap together, and an editor that also works on a phone.

Work should also be hard to lose: maps are kept across redeploys, and can be saved as named versions or exported.

It is built for a small, known group rather than a crowd. Clay Shirky calls this "software designed in and for a particular social situation" (Situated Software, 2004), and Robin Sloan describes making an app "for, and with, my family" (An app can be a home-cooked meal, 2020). The design borrows from tools people already trust:

• Excalidraw and tldraw: rooms joined by a link, not an account;
• Owlbear Rodeo: your own maps first, as pictures;
• Figma and Google Docs: named versions;
• Dungeondraft: walls drawn point by point.

The full list is in CREDITS.md.

What is enforced, and what is judged

Enforced by the checks in spec/, run on every push:

• A view link can never write.
• Each map's cells, events and activity stay inside that map.
• A change reaches everyone else within a second.
• Undo touches only your own changes, and never a collaborator's newer edit.
• A version restores the map exactly.
• Places and walls stay on land.

Judged by looking, under the rule in CLAUDE.md: a visual change isn't done until it has been rendered and compared with reference maps. That covers how the map looks and whether the phone layout is usable. ROADMAP.md records those judgements, including the failures.

What I chose not to build

• Accounts. A link is the permission, as in Excalidraw and tldraw.
• Locking land to one person. The map is a shared canvas, and last-write-wins is enough for one server (ADR.md).
• A city-scale isometric view.
• Unlimited undo. It is 30 steps; versions are the longer-term way back.

Known limits

• Undo history is lost on a server restart, and there is no redo.
• The server holds at most 150 private maps with something drawn on them.
• Walls are small in Chart view until you zoom in.
• The ground inside a walled town keeps its painted forest colour.

The first prototype, The Isle, still runs at /isle/, and a live log of who did what is at /logs/.