ActionBlock/doc

Action Blocks – Developer Documentation

Action Blocks is an online player-vs-player falling-block game. Players clear lines to send garbage to each other. They also collect items hidden inside pieces and use them on a player of their choice.

The project consists of two deployable components:

Component	Folder	Technology	Responsibility
Game server	actionBlocks_server/	C# / ASP.NET Core 10, SignalR	Runs all game logic, manages lobbies and players, pushes game state to clients
Website	actionBlocks_website/	React 19, TypeScript, Vite, CSS Modules, nginx	Renders the game, captures keyboard input, sends it to the server

Reading order

New to the project? Read these in order:

1. Architecture: how the pieces fit together, and why the server is authoritative.
2. Game rules: what the game actually does, with all numbers.
3. Server: a walkthrough of the C# code.
4. Protocol: the SignalR API between website and server.
5. Frontend: a walkthrough of the React code.
6. Development: running, testing and debugging locally.
7. Deployment: Docker, compose, reverse proxy and environment variables.
8. Extending: step-by-step guides for common changes (new item, new rule, new graphics, …).

Repository layout

.
├── actionBlocks_server/          C# solution (game logic + web host + tests)
│   ├── src/ActionBlocks.Game/    Pure game logic library (no ASP.NET dependency)
│   ├── src/ActionBlocks.Server/  ASP.NET Core host: SignalR hub, lobbies, tick loop
│   ├── tests/ActionBlocks.Game.Tests/  xUnit tests for the game logic
│   └── Dockerfile
├── actionBlocks_website/         React frontend
│   ├── src/                      Application code
│   ├── public/                   Static files copied as-is (graphics, config.js)
│   ├── docker/                   nginx config + container start script
│   └── Dockerfile
├── doc/                          This documentation
├── docker-compose.yml            Runs both containers
├── .env.example                  Template for deployment variables
├── instructions.md               The original project brief
└── tetris_instructions/          Reference material for the base rules (saved web page)

Glossary

Term	Meaning
Board / field	The 10×20 grid of a player. Internally it has 20 extra hidden rows above (the buffer).
Piece	One of the 7 four-cell shapes (internally named I, J, L, O, S, Z, T).
Mino	One of the four cells of a piece.
Active piece	The piece currently falling and controlled by the player.
Ghost	Preview of where the active piece would land. In the UI it is called the "drop shadow".
Hold	Slot where a player can park one piece. It can be used once per piece.
Garbage	Gray lines with one hole that rise from the bottom. They are sent by opponents' line clears.
Item	A special ability attached to one mino of a piece. You collect it by clearing that mino's row.
Target	The player your items are used on. It is selected with the number keys.
Snapshot	The full match state the server pushes to all clients many times per second.
Lobby	A group of players sharing a 6-character code. It hosts consecutive matches.
Match	One round inside a lobby, from countdown to winner.

Naming note: the project intentionally avoids the trademarked name of the original game in all user-facing text and graphics. Internally, the standard single-letter piece names (I, J, L, …) are used because they are the common technical vocabulary.