fcsouza/design-game-economy-design

Game Economy Design

Purpose

Virtual currencies, sinks/faucets, inflation control, reward balancing, and monetization integration. Genre-agnostic — applies to any game with resources, currencies, or tradeable items.

When to Use

Trigger: game economy, virtual currency, sinks and faucets, inflation, reward balance, loot tables, crafting economy, marketplace, monetization, pricing, premium currency, gold sinks, resource balance

Prerequisites

• game-design-fundamentals — core loop understanding
• postgres-game-schema — currency and item data models

Core Principles

Sid Meier: "A game is a series of interesting decisions" — economy makes decisions meaningful. Richard Garfield: "Elegant systems create depth from simple rules." Raph Koster: "Players will optimize the fun out of your game" — design economies that stay fun when optimized. Will Wright: "Simulation systems generate emergent behavior" — economies should emerge, not be scripted.

1. Every faucet needs a sink — if players earn currency, they must spend it; otherwise inflation destroys the economy
2. Two-currency model — soft currency (earned in-game, plentiful) + hard currency (premium, scarce, optional) keeps free players engaged while monetizing
3. Exponential costs, linear income — the natural idle game pattern; cost scaling must outpace earning to maintain engagement
4. Price anchoring — establish what things "should" cost early; players will judge all future prices against the first items they buy
5. Never sell power directly — sell time, cosmetics, convenience; pay-to-win destroys retention (Sid Meier principle)
6. Closed-loop economy — track total currency in circulation; if it grows unbounded, you have a leak
7. Test with spreadsheets first — simulate 100 hours of play before coding; if the spreadsheet breaks, the game will too

Step-by-Step Instructions

1. Define Currencies

List every currency: name, how earned, how spent, persistence on reset.

2. Map Faucets (Income Sources)

Every way players earn currency: combat rewards, quest rewards, daily login, achievements, trading.

3. Map Sinks (Spending Destinations)

Every way players spend: upgrades, crafting, shop, repairs, fees, taxes, cosmetics.

4. Balance the Spreadsheet

Create a spreadsheet simulating player income vs. spending over time. Target: net currency growth should be slow or zero at every stage.

5. Define Reward Tables

Use weighted random for drops, with pity system for rare items. Cross-reference quest-mission-design for quest rewards.

6. Integrate Monetization

Map premium currency to Stripe products via stripe-game-payments. Ensure premium currency can't break game balance.

Economy Health Metrics

| Metric | Healthy Range | Warning Sign | |--------|-------------|-------------| | Daily currency earned / spent ratio | 0.8-1.2 | > 1.5 (inflation) or < 0.5 (deflation) | | Median player currency held | 2-5x average purchase cost | > 20x (nothing to buy) | | Premium conversion rate | 2-5% of active players | < 1% (too expensive) or > 15% (too aggressive) | | Time to first meaningful purchase | 5-15 minutes | > 30 min (slow start) |

Cross-References

• postgres-game-schema — currency and item table schemas
• stripe-game-payments — premium currency and IAP integration
• quest-mission-design — quest reward balancing
• game-design-fundamentals — core loop reward schedules
• redis-game-patterns — leaderboard caching for economy rankings

Pitfalls & Anti-Patterns

• "Hyperinflation" — unlimited faucets with no sinks; currency becomes worthless
• "Pay-to-win" — selling direct gameplay advantages; kills free player retention
• "Currency confusion" — too many currency types; players can't understand what to spend
• "Dead economy" — nothing interesting to buy; currency accumulates uselessly
• "Exploitable loops" — crafting or trading loops that generate infinite value
• "Early abundance" — giving too much currency early; players expect it forever

Designer Philosophy

Sid Meier: The economy exists to make decisions interesting. If every choice has an obvious best option, the economy has failed. Players should regularly face "do I buy upgrade A or save for upgrade B?" dilemmas.

Richard Garfield (Magic: The Gathering): The best economies emerge from simple, elegant rules. A few well-designed resource types with clear trade-offs create more depth than a dozen currencies that nobody understands.

Raph Koster: Players will find the optimal farming strategy and grind it. Design your economy so that even the optimal path is fun, and the sub-optimal paths are still viable.

Sources

• "Designing Virtual Economies" — GDC 2017
• "Free-to-Play Game Economies" — GDC 2019
• "Theory of Fun" — Raph Koster
• "The Art of Game Design" — Jesse Schell, Chapter on Game Mechanics
• Stripe gaming best practices documentation