# 🛡️ Defence System

![Defence System](https://cdn2.vnations.net/images/buildings/defencesystem.png)

A **Defence System** is a network of fortifications that gives a region's defenders a large head start when an attack begins.

## Requirements

|     |     |
|-----|-----|
| **VBX cost** | 50  |
| **Productivity required** | 500 |
| **Materials** | 100 Iron, 100 Wood, 100 Steel, 100 Cement, 100 Plastic |
| **Appeal** | \+50 |
| **Prerequisites** | None |

## Effects

* **Invasions:** when an enemy launches an invasion of the region, the defending side starts the battle with **1,000,000 damage** already on the board for each Defence System the region's owner has there.
* **Uprisings:** both sides benefit. The occupying nation's Defence Systems count for the occupier, and any still owned by the region's original nation count for the rebels.
* The bonus is scaled by integrity. A Defence System at 50% integrity only adds 500,000 damage.
* Broken (0% integrity) Defence Systems give nothing.


:::warning
Every battle in a region knocks 5% integrity off all its structures. Repair your Defence Systems between battles to keep their full value.

:::

## See also

* [Bunker](/doc/bunker-F2nt3OJid8) · [Tank Trap](/doc/tank-trap-ptdLybHFCk) · [SAM Site](/doc/sam-site-kgj4j76KmB)
* [Infrastructure](/doc/infrastructure-tvXBC79OnR)