A multiplayer DOOM-like shooter implemented entirely in SQL, powered by CedarDB.

You read that right, everything is written in SQL: The renderer, the game loop, and the multiplayer sync.

This porject started as a thought experiment. Could we take DuckDB DOOM and crank it up to 11? Bigger viewport, more FPS, sprites, multiplayer support, while doing everything in SQL? Turns out, we can.

• Pure SQL renderer: Raycasting, sprite projection, occlusion, and HUD, all implemented as VIEWS.
• Multiplayer: CedarDB handles concurrent players, synchronization, and state.
• Hackable game state: Change config, teleport players, or balance weapons with a single UPDATE.
• First-class cheating support: Since everyone just talks SQL to the DB, half the fun is figuring out sneaky cheating queries.
• Minimal client: 150 lines of Python to capture key presses and display frames to your terminal.

• Tables: Everything is data: Maps, mobs, players, inputs, sprites
• Views: Layers of SQL transform state into a 3D view (scene, HUD, minimap)
• Game loop: A tiny shell script runs SQL at 30 Hz to advance bullets, check collisions, handle input, respawn players.
• Client: Queries the screen view, polls your keyboard, and pushes inputs to the DB.

• Docker
• Python 3 with psycopg2 installed
• A wide terminal window (seriously, zoom out, or you will have issues with line breaks)

docker pull cedardb/cedardb:latest
docker run --rm -p 5432:5432 -e CEDAR_PASSWORD=postgres --detach  cedardb/cedardb:latest
# Wait a few seconds for Cedardb to start
./server.sh

# in a second terminal window, zoom way out to have no line wraping issues
python3 pyclient.py

The client will connect as a new player, or reconnect you if you enter the same username you used previously.

• W, A, S, D movement
• Press X to shoot

Since everyone is a DB superuser, cheating is half the fun:

-- Infinite HP
UPDATE players SET hp = 100000 WHERE id = <your_id>;

-- Delete other players' inputs
UPDATE inputs SET action = NULL WHERE player_id != <your_id>;

-- Claim all bullets as yours
UPDATE mobs SET owner = <your_id> WHERE kind = 'bullet';

Pull Requests welcome! There is a lot of unfinished work. Some ideas for improvements: Adding powerups, multiple weapons, cleaning up the sprite LOD system, a better client, AI opponents, ...

I have taken and adapted a lot of code from the excellent DuckDB DOOM Demo. It also was the original inspiration for this project.