MBRG — Map Battle Royale Game
A Battle Royale for EU4 / RISK-style maps: every round one faction is
wiped out at random, and a neighbour swallows all of its provinces, until
only one is left standing.
The point isn't to play — it's to spectate and predict. The whole match is
computed from a seed, so everyone with the link already knows how it ends…
which is exactly why this release is a viewer and not a betting game (yet).
Status: v0.1.0-alpha
First playable release, and a first release on principle:
- ✅ One map (hand-made, embedded in the source)
- ✅ Deterministic simulation of the "Clásico" mode
- ✅ Round-by-round playback with animation, event log and live stats
- ✅ Shareable seed via the URL
- ✅ Spanish and English interface
- ❌ No server (no history, rankings or round schedule)
- ❌ No predictions or bets (coming in Phase 3)
- ❌ No Discord (Phase 4)
- ❌ No custom maps (the image importer is Phase 2)
One important warning
The seed lives in the URL and the match is computed in your browser. That
means anyone with the link can read the seed and work out the coming rounds —
i.e. spoilers. For a viewer that's harmless, but it breaks betting
completely: which is why this version ships no betting at all, and why
Phase 3 (precompute on the server, reveal one round at a time) is precisely
what fixes it.
How to play
- Open the live demo.
- Press ▶. Each round a faction falls and a neighbour takes it whole.
- Change the seed and hit Apply to generate a different match.
- Share the URL: it carries the seed, so whoever opens it sees exactly your
match.
Controls: mouse wheel or pinch to zoom, drag to pan, double-click to zoom in,
and the minimap in the corner to jump around.
The interface speaks Spanish and English — pick one in the sidebar, or force it
with ?lang=en / ?lang=es in the link. The choice is remembered.
Running it locally
npm install # install dependencies and link the workspace packages
npm run dev # dev server → http://localhost:5173
npm run build # compile the packages (tsc -b) and the web app (vite build)
npm test # tests (vitest run, no build needed first)
npm run test:watch
npm run typecheck
Structure
A TypeScript monorepo using npm workspaces. The same deterministic simulation
runs in the tests, the server, the bot and the browser — only the render layer
is meant to be swappable (e.g. for Three.js later on).
| Path | What's in it |
|---|
packages/shared | Map format (MapFormatV1), validation, adjacency, match types |
packages/sim | The engine: step() (one round), simulate() (whole match), seeded PRNG |
apps/web | The viewer: canvas renderer, playback, camera, minimap, log, stats, i18n |
"Clásico" rules
Each round:
- A living faction is picked at random.
- Its candidate neighbours are those sharing a border with any of its
provinces.
- One of them takes all of its provinces.
- Repeat until a single faction remains.
Roadmap
| Version | What it brings |
|---|
v0.1.0-alpha | The above: one map, no server |
v0.2.0 | Map importer: upload an image, turn it into a playable map |
v0.3.0 | Server + predictions: place bets, score points, keep rankings |
v0.4.0 | Discord bot: play from the chat, per-server leaderboards |
v1.0 | Multiple game modes, map editor, 3D |
License
MIT © 2026 Ángel García
