# Supply Chain Guide

**Entity Type:** Guide

This guide explains how supply chains work in Anno 117: Pax Romana, including setting up chains, using warehouses, managing limited resources, and creating hybrid supply chains.

## Overview

Supply chains govern your ability to provide for your citizens' needs, grow your city, and defend yourself in times of war. You use supply chains to harvest raw resources and process them into the goods your empire needs.

- **Early game:** Simple chains with 1 raw resource and 1 processing building
- **Mid game:** More complex chains involving multiple processing buildings
- **Late game:** Chains spanning multiple cities, islands, and provinces (Latium and Albion)

## Setting Up Supply Chains

### Basic Setup

All goods in a supply line need to be connected. This can be:
- **Direct connection:** Via roads
- **Indirect connection:** Through a Warehouse

The **green highlight** on your road shows the distance at which a supply chain can connect.

### Example: Timber Chain

1. Place a **Woodcutter** in a forested area (needs 80 trees within radius for max efficiency)
2. Place a **Sawmill** nearby
3. Connect both to your **Trading Post** with a road

### Example: Porridge Chain (Latium)

1. Build an **Oat Farm** with space for fields at edge of housing blocks
2. Connect to a **Porridge Stand**
3. The Porridge Stand can serve as a mid-way point bridging Oat Farm and Trading Post

## Using Warehouses

Warehouses act as "distribution nodes" or hubs for your supply chains. All goods within Warehouses are shared between all other Warehouses on the same island - they don't need direct connection.

### When to Use Warehouses

Move these supply chain elements outside your city center:
- Buildings with negative effects (e.g., Charcoal Burner: -3 Health, -3 Happiness)
- Farms, Woodcutters, and buildings requiring lots of space or natural resources
- Buildings requiring Mountain or River slots

### Warehouse Congestion

An **hourglass** above a Warehouse indicates transporters are busy. Solutions:
- Build a second Warehouse
- Upgrade existing Warehouse (requires technology)

### Warehouse Upgrades

| Upgrade Cost | Technology Requirement |
|--------------|----------------------|
| 250 Denarii, 25 Timber, 5 Tiles | Warehouse Organization |
| 500 Denarii, 50 Timber, 15 Tiles, 5 Concrete | Warehouse Refinement |

## Building Radius Effects

Buildings can have positive, negative, or mixed effects on nearby structures:

| Effect Type | Indicator | Example |
|-------------|-----------|---------|
| Positive | Green arrow up | Spinner: +1 Income (with research: +1 Knowledge) |
| Negative | Red arrow down | Charcoal Burner: -3 Health, -3 Happiness |
| Mixed | Half red/green diamond | Soap Maker: +1 Health, -1 Happiness |

**Tip:** Use farms as buffer zones - they take up space naturally, helping distance penalty-causing buildings like Charcoal Burner, Pig Farm, or Dye Maker.

## Limited Resources

Some buildings require special locations:
- **River Slots:** Clay Pit, Mill
- **Mountain Slots:** Iron Mine, Weaponsmith (needs Iron Ore)

Each island has limited slots - plan carefully or settle larger islands with more slots.

## Hybrid Supply Chains

Hybrid chains maximize limited resources by producing multiple goods from shared inputs.

### Example: Tiles and Amphorae

Using one Clay Pit to produce both Tiles and Amphorae:
- Clay Pit + Charcoal Burner + Resin Tapper + Potter + Tiler

### Example: Defense Production Chain

| Building | Requires | Cycle Time | Prod/Min |
|----------|----------|------------|----------|
| Iron Mine | N/A | 30s | 2t |
| Pig Farm | N/A | 30s | 2t |
| Salt Ponds | N/A | 30s | 2t |
| Charcoal Burner | Trees in Radius | 30s | 2t |
| Furnace | Iron Ore, Charcoal | 60s | 1t |
| Tannery | Pigs, Salt | 60s | 1t |
| Sandal Maker | Leather | 120s | 0.5t |
| Weaponsmith | Iron Ingots, Charcoal | 90s | 0.66t |
| Armourer | Iron Ingots, Leather, Charcoal | 90s | 0.66t |

### Defense Chain Layout

**Raw materials:**
- 1x Iron Mine (2t Iron Ore/min)
- 1x Pig Farm (2t Pigs/min)
- 1x Salt Ponds (2t Salt/min)
- 2x Charcoal Burner (4t Charcoal/min)

**Processing:**
- 2x Furnace (2t Iron Ingots/min)
- 2x Tannery (2t Leather/min)

**Final products:**
- 2x Sandal Maker (1t Sandals/min, consumes 1t Leather)
- 2x Weaponsmith (1.32t Weapons/min)
- 1x Armourer (0.66t Armour/min)

Consumes: 2t Charcoal, 2t Iron Ingots, 0.66t Leather

## Trade in Supply Chains

Each island has different **fertilities**, meaning you can't always complete a supply chain on one island.

### Example Fertilities

- **Island A:** Mackerel, Lavender, Grapes, Oysters, Iron
- **Island B:** Resin, Olives, Flax, Iron, Gold

### Solutions

1. **Purchase goods from NPCs**
2. **Found cities on new islands**
3. **Set up trade routes** (e.g., Amphorae and Olives for Mackerel)

### Cross-Province Trade

- **Latium exclusive:** Wine (valued in Albion)
- **Albion exclusive:** Cheese (needed by Equites)

Access province switching via:
- Trade screen buttons at top of map
- Globe button on mini-map (west-southwest position)

## Related

- [Production Ratio Guide](./production-ratios.md)
- [Timber Chain](./timber.md)
- [Porridge Chain](./porridge.md)
- [Defense Chain](./defense.md)
- [Tiles and Amphorae Chain](./tiles-amphorae.md)
