Area Defense Guide - Strategy and How to Unlock | Arknights: Endfield

Valley Pass
Level 1	Level 2	Level 3

Originium Science Park
Level 1	Level 2	Level 3	Level 4

Jingyu Valley
Level 1	Level 2	Level 3

Area Defense Guide for Arknight: Endfield. Includes tower and base defense tips, how to unlock, strategies, and how to defeat the enemies!

Table of Contents

Area Defense Stage Guides
Strategy and Tips
Area Defense Unlock Conditions
Area Defense Rewards
Early Warning Terminal Locations
What is Area Defense (Assault)?

Area Defense Stage Guides

Valley Pass

Level 1

Level 2

Level 3

Originium Science Park

Level 1

Level 2

Level 3

Level 4

Jingyu Valley

Level 1

Level 2

Check the Enemy Routes

The map on the Security Terminal screen shows the Command Core's position, enemy spawn points, and enemy invasion routes (red lines). Place Combat Facilities on the red lines to protect the Command Core.

Place the Turrets Near Merge Points

Due to the limited placement capacity for Combat Facilities, turrets must be positioned strategically along enemy paths. By placing turrets at overlapping enemy routes, you can maximize coverage and defend your base more efficiently while using fewer structures.

Check Enemy Information

Some enemies possess unique abilities. The optimal Combat Facilities will vary based on the enemy types, the Command Core’s location, and the selected Danger Level, so review these factors in advance. Enemy details can be checked via Enemy Intel when accessing the Early Warning Terminal.

Unlock the AIC Combat Plans

To create Combat Facilities, you need to unlock all the AIC Combat plans to get the machine blueprints. High-performance Combat Facilities are required to clear Auto-Defense with high Danger Levels, so if you don't have the ones you need yet, make sure to upgrade and unlock your AIC Plans accordingly.

Combat Facilities from Other Regions

Marsh Gas MK I	HE Grenade Tower

Combat Facilities unlocked through Industrial Plans in other regions can also be used for Base Defense. For example, the Marsh Gas MK I and HE Grenade Tower unlocked in Wuling can be manufactured and installed in Valley IV. You can also bring them in your Backpack.

Automated Industry Complex (AIC) Guide

Finish All Operator Interventions First

If there are multiple Risk Levels, clearing the Operator Intervention will unlock the next Risk Level. By finishing all Operator Interventions first and increasing the placement limit, you can clear Auto-Defense more easily.

Area Defense (Assault) Unlock Conditions

Complete the Defense Construction

You can unlock Area Defense by finishing the 'Defense Construction' sub-quest. This mission triggers once your Valley Pass base reaches Level 2. If it’s not available yet, focus on upgrading your base first to meet the requirements.

Area Defense (Base Defense) Rewards

Efficiently Increases Stock Bill Production
Auto-Defense Clear Grants Permanent Boost
Clearing Operator Intervention Unlocks Auto-Defense
Clear the Operator Intervention to Increase Limit

Efficiently Increases Stock Bill Production

Clearing the Area Defense (Assault) will increase the production efficiency of Stock Bills for that base. The effect is temporary for Manual Intervention, but clearing an Auto-Defense will make the effect permanent.

How to Farm Stock Bills

Auto-Defense Clear Grants Permanent Boost

Clearing an Auto-Defense permanently increases Stock Bill production efficiency. If multiple Danger Levels are cleared, the highest multiplier takes priority, making higher-level Auto-Defenses more effective for boosting production.

Higher Levels Greatly Boost Stock Bill Efficiency

At Level 3, use Operator Intervention to efficiently increase Stock Bill earnings within a few runs. Once your setup is strong enough, unlock and transition to Auto-Defense to maintain peak production efficiency without manual input.

Clearing Operator Intervention Unlocks Auto-Defense

For each Risk Level, you cannot immediately challenge the Auto-Operation. The system is designed to clear the Operator Intervention first, so that you can finally unlock the Auto-Defense option.

Clear the Operator Intervention to Increase Limit

Completing the Operator Intervention for the first time will give you Oroberyl and T-Creds, but the most notable reward that you will get is the Combat Facilities Capacity, which increases the number of combat facilities that can be placed within your outpost.

Early Warning Terminal Locations

Three Locations

Security Terminals are located in three places: Valley Pass, Originium Science Park, and Jingyu Valley. There is one icon for each base, so check their locations on the map.