Designing a Player-Driven Economy: Faucets, Sinks, and 45 Resource Types

The Bathtub Model

Every virtual economy is a bathtub. Resources flow in through faucets (mining, NPC drops, quest rewards) and flow out through sinks (crafting costs, repair fees, item destruction). If your faucets run faster than your sinks, the tub overflows and you get hyperinflation. If your sinks drain faster than the faucets fill, the economy deflates and new players cannot afford to participate.

When we started designing the economy for Outer Directive, we pinned the bathtub model to the wall and never took it down. Every feature, every mechanic, and every number in the game gets evaluated through this lens: does this add a faucet, a sink, or neither? If it adds a faucet, what sink balances it?

This sounds simple in theory. In practice, it is one of the hardest design challenges in game development. Players are relentlessly efficient optimizers. They will find every exploit, every arbitrage opportunity, and every unintended interaction between systems. The economy has to be robust enough to handle that pressure while still feeling rewarding.

Why 45 Resource Types Across 5 Tiers

We settled on 45 distinct resources organized into 5 tiers of increasing rarity and complexity. This was not arbitrary. The resource count serves several design goals simultaneously.

Tier 1 (Raw Materials): Abundant ores, gases, and minerals found across most star systems. These are the entry point for new players. You can mine Tier 1 resources with basic equipment and sell them on local markets within your first session.

Tier 2 (Processed Materials): Created by refining Tier 1 resources. This introduces production chains and gives industrial players their first meaningful gameplay loop.

Tier 3 (Components): Manufactured from Tier 2 materials, often requiring multiple types. Building Tier 3 components demands either a diversified mining operation or trade relationships with other players for the inputs you lack.

Tier 4 (Advanced Components): These require specialized facilities and Tier 3 inputs from different production families. No single player or small corporation can efficiently produce all Tier 4 components alone, which forces economic interdependence.

Tier 5 (Strategic Materials): Extremely rare, found only in specific regions of the map, and required for the most powerful ships and structures. Control over Tier 5 resources is a primary driver of sovereignty warfare and alliance politics.

The 45-type system creates natural specialization. A mining corporation might focus on a specific family of Tier 1 and Tier 2 resources, selling their output to industrial players who specialize in Tier 3 component manufacturing. Those components flow to shipyards that build hulls, which get fitted with modules from yet another supply chain. The result is an economy where everyone depends on everyone else.

The 10 Resource Sinks

Faucets are easy. Sinks are where economy design gets hard. Players psychologically resist having things taken from them, so every sink has to feel fair and purposeful. Here are our 10 core sinks and the design reasoning behind each.

1. Ship Construction: Building ships consumes resources permanently. This is the largest sink by volume and the most psychologically acceptable because players receive a tangible asset in return.

2. Module Manufacturing: Fitting modules for ships follows the same logic as hull construction. Modules are consumed in production and can be destroyed in combat.

3. Structure Construction: Bases, stations, refineries, and sovereignty structures all require significant resource investment. This sink scales with territorial ambition.

4. Ammunition and Consumables: Combat consumes ammunition, drones, and fuel. This creates a steady drain that scales with military activity across the universe. Wars are expensive, as intended.

5. Ship Destruction: When a ship is destroyed in combat, a percentage of its fitted modules and cargo are destroyed permanently. The rest drops as salvage. This is the most important sink in the game because it directly connects economic activity to military activity.

6. Structure Decay: All player-built structures require periodic maintenance using resources. Abandoned or neglected structures slowly degrade and eventually become vulnerable. This prevents the universe from accumulating infinite structures over time.

7. Upkeep Costs: Sovereignty, alliance infrastructure, and certain station services require ongoing resource payments. This sink scales with the size of a player organization, creating natural pressure against infinite expansion.

8. Research and Technology: Unlocking new blueprints and upgrading existing ones consumes resources. This gives industrial players a reason to produce beyond immediate market demand.

9. Market Transaction Fees: Every market transaction takes a small percentage cut. This sink operates invisibly but consistently, scaling with total economic activity.

10. Jump Gate Fuel: Moving ships between star systems consumes fuel, a Tier 2 resource. This ties logistics costs directly to the economy. Moving a large fleet across the map is not just a time investment; it is a resource investment.

Each of these sinks was calibrated through simulation before we ran live player tests. We built an economic simulator that models resource flows at scale, letting us adjust faucet and sink rates before real players interact with the system.

Localized Markets (and Why Not a Global Auction House)

One of our most debated design decisions was rejecting a global auction house. In many MMOs, you can list an item for sale and any player anywhere in the world can buy it instantly. This is convenient, but it destroys an entire category of gameplay.

In Outer Directive, markets are localized. A station in the northern frontier has its own order book, independent of a station in the southern core regions. If resources are cheap in one region and expensive in another, someone has to physically move those resources to capture the price difference.

This creates several emergent systems that a global auction house would eliminate.

Trade routes become real. Players (and player organizations) establish regular logistics runs between regions, creating supply lines that can be defended or disrupted.

Regional price variation creates content. A war in one region drives up the price of ammunition and ship components locally. Savvy traders spot the opportunity and run supplies to the front lines at a premium. Savvy pirates spot the traders and set up ambushes along the route.

Geographic advantages matter. Controlling a system with rare Tier 5 resources gives your alliance genuine economic leverage, but only if you can move those resources to market safely through your logistics network.

Blockades work. If an enemy alliance controls the jump gates between your industrial systems and your market hub, they can functionally strangle your economy without destroying a single structure.

The tradeoff is convenience. It takes more effort to buy and sell in our system. We accept that tradeoff because the gameplay it creates is worth more than the convenience it costs.

Physical Logistics Prevents Teleportation Exploits

In games with instant item transfer, economic systems become math problems. The optimal solution is always calculable, and the economy converges on efficient equilibrium quickly. That equilibrium is stable but boring.

By requiring physical transport of all goods, we introduce risk, time, and player interaction into every economic transaction. A purchase is not complete when you click "buy." It is complete when the cargo arrives at its destination. Between those two moments, anything can happen: pirate ambushes, territorial disputes, navigational miscalculations through hostile space.

This also prevents a common exploit in MMO economies where players use instant transfer to manipulate prices across distant markets simultaneously. In Outer Directive, if you want to arbitrage between two markets, you need to commit ships and time to the operation, which means committing to risk.

Quantum Cores: Premium Currency That Is Not Pay-to-Win

Quantum Cores are Outer Directive's premium currency. You can purchase them with real money. Here is what they can buy: cosmetic ship skins, visual effects, UI themes, and convenience features like additional bookmark slots.

Here is what they explicitly cannot buy: ships, modules, resources, combat advantages, production speed boosts, or anything that affects the competitive landscape. We do not sell power. Full stop.

This was a non-negotiable design principle from day one. In a player-driven economy, selling resources or combat advantages for real money poisons the entire system. It means that economic outcomes are determined by wallets rather than strategy. It means that military conflicts are won by spending rather than planning. It undermines every other system in the game.

We fund development through cosmetics and we plan to sustain the game through cosmetics. The economy belongs to the players.

Monthly Economic Reports

Every month, we publish economic reports to the community. These reports include aggregate data on resource production and consumption volumes by tier, trade flow patterns between regions, price indices for key commodities, ship destruction and production statistics, and the overall health metrics of the bathtub model.

We publish these reports for two reasons. First, transparency builds trust. Players can see that we are monitoring the economy and that we take its health seriously. Second, the data itself becomes gameplay. Alliance leaders use the reports to identify economic opportunities. Market analysts spot trends. Military strategists assess which regions are economically vulnerable.

The economy is the foundation that every other system in Outer Directive builds on. Getting it right is a continuous process, not a one-time design task. We monitor, we adjust, and we keep the bathtub at exactly the right level.

Want to participate in a player-driven economy built on these principles? Explore the economy features or join our Discord to talk shop with the community.