Armored Core Wiki
Mission icon LINE OF DEFENSE

Line of Defense Mission Icon

Line of Defense is a mission in the fourth chapter of Armored Core 4.



  • Damage: 25700 AP (32700 AP on hard mode)
  • Ammo Use: 120,000C
  • Mission Time: 330 seconds


Let's confirm the mission

A large Interior squadron has taken hold of the Robert Mayer Bridge. It's up to you to eliminate them.

The enemy's forces consist mostly of Normals. There are quite a few of them to deal with.

According to a support unit that went on ahead, they've set up special barricades throughout the area that are highly effective against gunfire.

We also believe there's a chance they've got some new kind of experimental weapon. Keep your wits about you.

Those are your orders.


The player is air-dropped into the canyon below the Robert Mayer Bridge, and is tasked with clearing the Interior forces from the area. The enemy forces are grouped into squads, and are partly protected by bullet-resistant barriers. Once approximately half of the enemies are destroyed, aerial units will arrive to reinforce them. The mission ends once all of the enemy forces are destroyed.

Hard Mode Differences: The reinforcements that arrive part way through the mission will be accompanied by a Fermi aerial fortress and Leonemeccanica's Lynx Sir Maurescu. Sir Maurescu must be defeated along with the rest of the enemy forces in order to complete the mission, however the aerial fortress can be ignored.



Fiona Jarnefeldt:Eliminate all enemy troops. We've received word that more are on their way. Carry out your mission as swiftly as possible.


Fiona Jarnefeldt:Now commencing mission.

Fiona Jarnefeldt:Enemy reinforcements have entered the combat area. Not long before contact now. Prepare to intercept.

Fiona Jarnefeldt:(Hard Mode) Enemy reinforcement confirmed! It's a Next!

Sir Maurescu:(Hard Mode) So you're Anatolia's Mercenary.

Sir Maurescu:(Hard Mode) Let me remind you of your place!

Fiona Jarnefeldt:(Hard Mode) Enemy Next successfully identified. It's Number 9-- Leone's Sir Maurescu

Sir Maurescu:(Hard Mode) Ahhhh!! But I'm... Why?

Fiona Jarnefeldt:(Hard Mode) Sir Maurescu defeated.

Fiona Jarnefeldt:Enemy squadron is unresponsive. The mission was a success. Good work. Please head back.


  • The mission is named Defend Line in the Japanese version.