This directory decomposes the "simple economy" replacement into one implementable unit per file. Each file is written as a self-contained prompt: a future session should be able to pick up one file and implement it without re-reading the whole codebase.

The existing economy is not deleted. It is frozen as the hard economy and kept selectable. The simple economy is the default from now on.

1. Shared project context (read this first)

Battle for 'Tismo is an HTML5 port of a turn-of-the-millennium strategy game. Pure JavaScript, no build step, no runtime dependencies.

Server-authoritative. shared/game_state.js (GameState) is the model; server/game_server.js validates orders; the browser renders snapshots and sends orders back. The client never runs GameState against a live game.
GameState is mixins. shared/game_state.js composes the modules in shared/game_state/ onto the prototype (Object.assign of each *Methods export). All state lives on the one instance.
Shared logic runs in Node and the browser. shared/ must stay framework-free (no Node built-ins, no DOM). server/websocket.js is the only place Node built-ins are expected.
Data lives in shared/data/ (barrel: shared/data.js); import from the barrel, edit the file under shared/data/.
No new libraries. Everything is hand-written; only the vendored jQuery under client/vendor/ is third-party. Indent .js with 2 spaces.
Tests live in tests/<topic>_test.js extending TestCase (base in tests/framework/). During development run one suite: node tests/run_tests.js --file <name>.js. Never run the full suite by hand; the commit hook runs it.
Snapshot cost matters. Large collections are delta-shipped via DELTA_COLLECTIONS in server/game_server.js, each paired with the versions key that reports it. A new snapshot collection needs an entry and a version, or it ships on every 10 Hz broadcast.
UI changes need approval. Per AGENTS.md, any change that alters what the player sees must first be shown as a minimal standalone HTML example opened in the user's Firefox, and only committed once the user has seen and approved it. See 09-ui.md.

Commands

Install once: npm install.
One suite: node tests/run_tests.js --file <name>.js.
Server: node server/server.js --port 27015 --bind 127.0.0.1.

2. The simple economy at a glance

Area	Hard economy (today)	Simple economy (target)
Resources	per-region/tile stores, transport, trade graph	one global pool per player, available everywhere
Production buildings	private agents with cash/debt/upgrades	public, output to the player's pool
Building	gathers steel/high-tech over days, then builds	starts immediately, speed driven by regional energy
Construction capacity	`GDP` → `ECONOMY.productionCapacity`	energy available in the region, with modifiers
Warmup	settles the world until prices are steady	none
Currency	one per nation, floating FX, central banks	euro (€) only, no conversion
Money use	construction, training, internal bills	market purchases only
Taxes	trade taxes (sales/export/import)	1 inhabitant = 100 €/day × (approval × 2) × modifiers
Market	read-only reference prices, drifting	global buy/sell market in the Resources tab
Procurement	bidding across reachable stores + global market	draw from the player's pool, no bidding
Migration	income-driven people move between regions	no economic migration

Open questions are called out in each module file; settle them before or while implementing that module.

3. Suggested order and dependencies

Implement in this order. Later modules assume the earlier switch exists.

01-decoupling-hard-economy.md — the economyModel switch everything hangs off. Do this first.
02-resource-pool-and-production.md — the pool and public producers.
03-construction.md — immediate build, energy-driven speed, starting plants.
04-warmup.md — skip the settle in simple mode.
05-money-and-taxes.md — euro-only treasury and per-inhabitant income.
06-global-market.md — the global market and its order.
07-procurement.md — pool draws instead of bidding.
08-migrations.md — turn off economic migration.
09-ui.md — the visible changes (approval gate).
10-snapshot-and-orders.md — wire protocol and server validation.
11-tests.md — test plan spanning the above.

10 is naturally interleaved with 02, 05, 06 and 07; treat it as the checklist for the wire shape of whatever those modules add.

4. Cross-cutting rules for every module

Keep the hard economy working when economyModel === "hard". Do not delete hard code paths; gate them.
Default economyModel is "simple" everywhere it is not explicitly set.
Do not add libraries; do not touch client/vendor/.
Every new snapshot field must be cheap and versioned.
Add or extend the matching tests/<topic>_test.js; run only that file.
No comments unless the surrounding file already uses them heavily; match the house style (the code is heavily commented on purpose — follow suit for new modules).
Commit only when asked; the hook runs the full suite.

5. Module index

File	Module
`01-decoupling-hard-economy.md`	The economy-model switch; freeze current model as hard.
`02-resource-pool-and-production.md`	Global pool per player; public production buildings.
`03-construction.md`	Immediate building; speed from regional energy; starting plants.
`04-warmup.md`	No warmup in the simple economy.
`05-money-and-taxes.md`	Euro only; per-inhabitant approval tax; drop taxes tab.
`06-global-market.md`	Global market, lots, price formula, starting stock.
`07-procurement.md`	Regions draw from the player's pool; no bidding.
`08-migrations.md`	No economic migration.
`09-ui.md`	All client changes (approval gate).
`10-snapshot-and-orders.md`	Snapshot fields, deltas, server order handling.
`11-tests.md`	Test plan and fixtures.

README.md Unescape Escape

Simple economy — implementation prompts