RFDGameStudio

The Idea

Most game engines are built for one game. The engine I wanted to build is a studio � a set of shared primitives that compounds across games rather than getting rewritten from scratch every time.

RFDGameStudio is four complete games sharing one engine. Every mechanic that survives production in one game gets promoted to a primitive available to all games that come after.

The Four Games

Horse Racing Sim � Discrete event engine. Horses have genetics, form, and career stats. You bet, breed, and build a stable. Tests the Port-Engine pattern: pure Lua logic exposed as a clean API that both TypeScript and PyGame consume identically.

Slither Rogue � Real-time snake roguelike with evolution cards. Collision detection, real-time tick loop, emergent power systems. Tests the real-time physics primitive at speed.

Mutant Battle Ball � 2v2 possession-based combat sport. Mutants have parts (head, chest, arms, legs) that drive stats and visual appearance. Tests the possession system, AI role assignment, and composite figure rendering.

SlimeCoin � Coin-pusher roguelike with a token economy. Three physics layers (shelf, floor, vat), pairwise chip synergies, a shot queue, and a mid-round exchange system. Directly inspired by Raccoin. Tests economy loops and physics simulation.

The Engine

The stack is deliberately minimal:

data.yaml    -- entity definitions, config, opponent data
logic.lua    -- game simulation (runs identically everywhere)
TypeScript   -- browser renderer (Vite + React)
PyGame       -- desktop renderer (same logic.lua, different canvas)

Lua was chosen because it runs in both environments without modification. The same tick_game(dt, input) call that drives the browser also drives PyGame. The renderers are interchangeable. The logic is never duplicated.

Shared primitives in engine/primitives/:

  • movement.lua � vector math, move_toward, atan2
  • physics.lua � grid collision, wall bounce, coin physics
  • action.lua � input handling, collect() for Lua/Python bridging
  • resolution.lua � weighted outcomes, affinity scoring
  • lifecycle.lua � entity lifecycle event constants

Each primitive was extracted when the same logic appeared in two or more games. Nothing was abstracted speculatively.

The Methodology

Every feature starts as a directive:

  1. Scope defined � files listed, read-only files named explicitly
  2. Test anchors written � behavior specified before implementation
  3. Agent implements
  4. Floor verified � raw pytest output only, never agent summaries
  5. Phase certified � floor locked, next phase begins

Current certified floors: 86 passed, 0 failed (Python) and 39 passed, 0 failed (TypeScript).

No phase advances without a passing floor. No exceptions.

The MCP Server

RFDStudioMCP runs as an NSSM service with 11 tools for live game inspection:

  • studio_load_game � load any game by ID
  • studio_get_state � inspect live GAME_STATE
  • studio_call � call any Lua function directly
  • studio_screenshot � render a frame and return PNG
  • studio_run_tests � run the full test suite
  • studio_balance_report � simulate N races, return win distribution

The studio is designed to be interrogated, not just played.

Coming to The Arcade

All four games will be playable in the browser. The Vite build produces a static dist/ that deploys to The Arcade. PyGame ports serve as the desktop and development renderer.

GitHub: RFDGameStudio

Built with Lua, TypeScript, and Python. Four games, one engine. The engine is the point.