arda

Deterministic fantasy worldgen for tabletop games. One seed produces one continent, resolved down to the 5-ft squares of a D&D battle map, with geography that holds up to scrutiny: rivers run where water would go, villages sit on river terraces, roads follow the terrain that carries them.

Status: design finished, implementation not started. The repository will grow a Rust workspace; nothing here is usable yet.

What it generates

Three tiers sharing one coordinate system:

• Continent (default 500×1000 km, configurable): plate tectonics coupled with erosion, climate from latitude and orography, major rivers, settlement density, trunk roads, realms with borders.
• Areas (51.2 km tiles, 512×512 cells of ~100 m): relief, hydrology, climate, vegetation, settlements, land use and roads, each stage computed only from the stages before it. Adjacent tiles agree on every shared edge by construction.
• Blocks (64×64 five-ft squares per cell): tile grids filled by constrained WFC. Rivers and roads cross block boundaries without breaking; a standard battle map is a quarter block.

The world also carries named regions, ranges, rivers and seas; towns, villages and hamlets with populations and site tags; buildings with type and footprint; and named NPCs with D&D-style stat sheets.

Everything derives from a single 64-bit seed. The same seed and config produce a byte-identical world on any OS — share the seed, not the gigabytes.

Planned usage

# generate a world (hours; runs on a 16 GB desktop)
arda generate --seed 42 --out worlds/w42

# export maps and data
arda export --world worlds/w42 --area 03_11 --cell 300,128 --format png,json

# serve a world read-only over HTTP (for VTT integration)
arda serve worlds/w42 --port 8080

Also usable as a library (arda on crates.io, eventually) and as a docker image with a mounted output volume.

Output

• Per-cell data: height, cover, climate, hydrology, roads, ownership.
• Objects: rivers, lakes, settlements, roads, crossings, passes, realms, buildings, NPCs.
• Renders: cartographic continent/area maps and battle-map PNGs, plus versioned JSON for everything, including per-tile attributes (traversability, movement cost, cover, hazards) for game engines.

License

MIT or Apache-2.0, at your option.