Sea Spider Armored Core 6
Screenshot by Prima Games.

How to Beat IA-13 Sea Spider in Armored Core 6 (AC6)

Don't stop firing

The IA-13 Sea Spider is the final boss standing between Chapter 3 and access to the PvP multiplayer component of Armored Core 6. Just like Balteus though, this fight is a major skill check that pushes your build to its limits, and I will cover exactly how I was able to beat the spider in my AC6 boss guide.

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How to Defeat the Sea Spider Boss in Armored Core 6

To beat the Sea Spider in AC6, you need to consistently apply damage with weapons such as Gatling Guns or plasma rifles to cause the boss to stagger. The spider nullifies the stagger you built up incredibly fast in between attacks, so keeping that AC Impact Meter as high as you can makes all the difference in this battle.

I recommend having a weapon on each arm and missile launchers on either shoulder. In my own fight against the Sea Spider boss, I used two Gatling Guns, a 10-cell missile launcher, and a 4-cell missile launcher. At almost every point in the fight, I was dealing damage from at least one weapon, and the spider melted real quick.

Sea Spider Phase One Tips in AC6:

As soon as the Sea Spider spawns, you want to dump all of your damage on the boss. By the time it starts attacking, it should be on the brink of staggering. You will likely need to dodge at least one round of missiles, and then you can go back to shooting.

Screenshot by Prima Games.

Throughout the first phase, the boss is super aggressive and will shoot all kinds of energy missiles at you. However, the largest threat is the melee attack where it lifts up its front legs and slams down. Any time this happens, just boost forward. You will go directly by the boss and bypass any potential damage.

Related: All Mech Parts in Armored Core 6 (AC6) Listed

In between missiles and melee attacks, I simply spammed all my weapons while strafing around the boss. I found it easier to stay grounded for this part of the fight so I could easily dodge the melee attacks and deal more damage.

Sea Spider Phase Two Tips in Armored Core 6

Screenshot by Prima Games.

When the Sea Spider reaches about 40% health, it will start floating in the air, and you should absolutely follow. If you stay on the ground, you will be pelted by beams of energy, and hitting the boss will be more challenging than ever. You need to try and float above the boss as much as possible.

Of course, that comes down to managing your energy, but if you position yourself in the air, the IA-13 Sea Spider is more vulnerable than ever. Unleash everything you have at this point before one of the giant beams tears you apart and the fight is over in a flash.

Best Build for the Sea Spider Fight in AC6

For the best loadout against the Sea Spider, you want two missile launchers and two Gatling Guns. An alternative to the Gatling Guns is plasma rifles or one of each. But the main idea is to have constant damage to the boss. You don’t need to worry too much about defense, so as long as your EN Load is useable, then the rest is fine. The build I used to beat the spider is below.

My build for this battle in AC6. (Screenshot by Prima Games)

Best Loadout to Beat the Sea Spider:

  • R-Arm Unit: DF-GA-08 HU-BEN
  • L-Arm Unit: DF-GA-08 HU-BEN
  • R-Back Unit: BML-G1/P20MLT-04
  • L-Back Unit: BML-G2/P05MLT-10
  • Head: VP-44S
  • Core: CC-2000 Orbiter
  • Arms: AC-2000 Tool Arm
  • Legs: LG-012 Melander C3
  • Booster: BST-G2/P04
  • FCS: FCS-G2/P10SLT
  • Generator: DF-GN-06 Ming-Tang
  • Expansion: Nothing

Feel free to use this build as a baseline or even experiment with your own loadouts in Armored Core 6. After all, there is no single answer to boss fights in the game, and getting creative with your AC parts is part of the loop.

Don’t forget that defeating the Sea Spider will unlock the PvP multiplayer within Armored Core 6.

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Daniel Wenerowicz
Dan has been writing gaming guides, news, and features for three years after graduating with a BA in writing . You can find him covering Call of Duty for eternity, action-adventure games, and nearly any other major release.