# Items

This document defines the intended item vocabulary for the simulation.

Items are the goods that move through the economy, sustain population, enable construction, and support logistics.

The goal of this document is not to lock every final item name immediately. It is to define the categories and roles that the economy depends on.

## Design Goals

The item model should support:

- market-driven trade
- construction demand
- station operation
- workforce support
- transport specialization
- future industrial depth without immediate overcomplication

## Core Principles

- items should have clear economic purpose
- items should belong to recognizable categories
- population needs should be represented with real goods
- station construction should consume real goods
- cargo specialization should matter where useful

## Major Item Categories

The intended categories are:

1. raw resources
2. processed industrial goods
3. life-support goods
4. civilian goods
5. construction goods
6. population-related units
7. special logistics goods later

## Raw Resources

These are extracted directly from the world or from near-direct processing.

Examples:

- ore
- gas
- water if treated as an extractable resource
- biological feed inputs later if needed

Raw resources are the base of the production chain.

## Processed Industrial Goods

These are materials produced from raw resources and used for further production.

Examples:

- refined metals
- structural materials
- electronics later
- machinery later

These goods should feed construction, station operation, and advanced industry.

## Life-Support Goods

These are required to sustain population.

Core life-support goods:

- food
- water
- energy

These are not optional luxuries. They are fundamental operating requirements for workforce survival.

## Civilian Goods

These are goods consumed by population beyond pure survival.

Current important example:

- consumer goods

These goods should matter for workforce health, quality of life, and possibly future growth modifiers.

## Construction Goods

These are the goods used to build stations and possibly ships.

Examples:

- station construction materials
- ship construction materials
- module construction materials

The exact item split can remain flexible for now, but construction should consume real goods rather than abstract progress only.

Construction storage at a station site should create demand for these goods through the normal market system.

## Population-Related Units

Population itself should be treated as a tracked resource, but not as an ordinary trade good in the same sense as ore.

Important distinctions:

- workers are population units
- commanders are population-derived special units
- workers can be transported
- commanders are created from population over time

Population transport should remain controlled by workforce and ship rules rather than being treated as a trivial cargo commodity.

## Livestock And Food Loop

Livestock should exist as part of the food loop.

This implies:

- livestock is distinct from workers
- livestock may require dedicated transport or handling rules later
- livestock supports food production rather than station staffing

## Item Role Examples

The current design implies at least these roles:

- `ore`
  - raw industrial input

- `food`
  - workforce life-support

- `water`
  - workforce life-support

- `consumer-goods`
  - workforce support / civilian demand

- `workers`
  - transported population units

- `construction-materials`
  - station and module building input

The final names can change, but the economic roles should stay stable.

## Storage And Compatibility

Not every item should necessarily fit in every hold type forever.

Useful distinctions later may include:

- solid storage 
- liquid storage
- container storage
- passengers
- livestock

For now, the important rule is simply:

- item class should eventually matter for transport and storage design

## Market Behavior

Items should participate in the market according to their role.

Examples:

- life-support goods generate recurring demand
- construction goods generate burst demand during expansion
- industrial goods feed production chains
- worker transport supports station staffing

This should help the economy create natural recurring and temporary market pressures.

## Item Importance To Other Systems

Items are the bridge between major game systems:

- [ECONOMY.md](/home/jbourdon/repos/space-game/docs/ECONOMY.md)
  - buy and sell orders are item-driven

- [WORKFORCE.md](/home/jbourdon/repos/space-game/docs/WORKFORCE.md)
  - population survival depends on specific goods

- [STATIONS.md](/home/jbourdon/repos/space-game/docs/STATIONS.md)
  - station construction and operation consume goods

- [SHIPS.md](/home/jbourdon/repos/space-game/docs/SHIPS.md)
  - ship transport depends on what kind of item is being moved

## Minimum Rules

The following rules should remain true unless deliberately revised:

- workforce depends on real support goods
- station construction depends on real construction goods
- industrial chains are item-based
- workers are movable population units
- commanders are not ordinary trade cargo
- livestock is distinct from workers
- item categories should eventually matter for storage and transport
