AC6 FCS Comparison: Best Parts for Each Build (Reg 1.09.1)

※This article is based on information for Regulation 1.09.1 (as of 2025/05/23).

In ARMORED CORE VI FIRES OF RUBICON, your Assembly / Build determines your AC's performance. Among these, the FCS (Fire Control System), which acts as the "eyes" to track enemies, is an extremely vital internal part that dictates the outcome of battles. No matter how powerful the weapons you equip, if your FCS doesn't align with your combat style, it cannot unleash its true potential. This article thoroughly compares and explains the performance and features of optimal FCS for major builds: close-range, mid-range, long-range, and missile-specialized.

FCS Role and Basic Performance

The FCS is a part that governs target lock-on performance. FCS performance is primarily determined by the following five parameters:

• Close-Range Assist Aptitude: Affects lock-on accuracy and speed at distances under 130m. Higher values mean better target tracking during close-quarters infighting.
• Mid-Range Assist Aptitude: Performance at distances between 130m and 260m. As most firefights occur at this range, it's a critical parameter for many builds.
• Long-Range Assist Aptitude: Performance at distances over 260m. Essential when long-range weapons, such as sniper rifles, are your primary armament.
• Missile Lock Correction: Affects missile lock-on speed. A crucial stat if you frequently use missiles.
• Multi-Lock Correction: Performance when locking onto multiple enemies simultaneously. Important when utilizing split missiles and similar weapons.

In addition to these performance metrics, "Weight" and "EN Load" also impact the overall Assembly / Build. High-performance FCS parts can strain your AC's Load / Carrying Capacity and energy efficiency, requiring you to consider mobility and synergy with other parts. Choosing the optimal FCS based on your preferred combat range and primary weaponry is the first step towards victory.

Major FCS Performance Comparison List

Here, we've compiled a list of representative FCS parts with high adoption rates for each build. Focus on the distinctive performance of each part and compare it with the direction of your Assembly / Build.

Recommended FCS by Build and Playstyle Explanation

Close-Range Specialized Build

An infighting style that closes in on enemy ACs with shotguns and machine guns. Constantly moving at high speed, assist performance for continuously tracking enemies is paramount.

IA-C01F: OCELLUS

• Pros: An overwhelming Close-Range Assist Aptitude of 90. Once locked, it boasts incredible lock retention, sticking to enemies even through their Quick Boost (QB) or high-speed maneuvers.
• Cons: Assist performance at mid-range and beyond is virtually non-existent, immediately putting you at a disadvantage if the distance is increased even slightly. Furthermore, with the significant reduction in Missile Lock Correction in Regulation 1.07, its synergy with missile weaponry has worsened.
• Ideal Builds: Pure close-combat ACs, such as those wielding shotguns in both hands and pile bunkers on the shoulders. Optimal for tactics that involve staying close to the opponent and aiming for high damage after a stagger.

FC-006 ABBOT

• Pros: A high Close-Range Assist Aptitude of 70, sufficient despite being inferior to OCELLUS. The biggest difference from OCELLUS is its good balance, allowing it to handle mid-range to some extent, and its decent Missile Lock Correction.
• Cons: While versatile, it lacks the overwhelming specialized performance of OCELLUS. You might find it inferior to other FCS parts when fighting at awkward distances.
• Ideal Builds: ACs that primarily focus on close-range combat but also wish to use deterrents like hand missiles. A strong alternative if you find OCELLUS's extreme specialization doesn't suit your playstyle.

Mid-Range / Balanced Build

A style that utilizes assault rifles as primary weaponry to engage in stable firefights at distances of 130m to 260m. This is a fundamental form of Assembly / Build, commonly adopted by many players.

FCS-G2/P05

• Pros: A very high Mid-Range Assist Aptitude of 80, demonstrating unparalleled strength in engagements at this distance. Its low weight and EN Load are also appealing, offering high cost-performance without hindering Assembly / Build freedom.
• Cons: Standard performance at close and long ranges; it's not advisable to challenge specialized builds on their own turf.
• Ideal Builds: Orthodox mid-weight bipedal Armored Core (AC) equipped with assault rifles or linear rifles. If you seek stable performance, this part is an excellent starting point.

IB-C03F: WLT 001

• Pros: A versatile FCS boasting high assist aptitude at all ranges. Its mid-range performance is particularly strong, allowing flexible responses to sudden close-quarters engagements or when distance is created. Its Missile Lock Correction is also high, truly leaving no blind spots.
• Cons: Its top-class EN Load among all FCS is its biggest drawback. When using this part, generator options are severely limited, and overall AC energy management becomes stringent.
• Ideal Builds: Heavyweight ACs equipped with Coral generators that have ample EN output, or any Assembly / Build that can tolerate the high EN Load. The returns are expected to far outweigh its shortcomings.

Long-Range Specialized Build

A style that utilizes sniper rifles and long-range cannons to unilaterally attack from an out-of-range position where enemy attacks cannot reach. Maintaining distance is vital for this tactic, making it suited for experienced players.

VE-21A

• Pros: An astonishing Long-Range Assist Aptitude of 92. Its overwhelming performance, unmatched by others, enables precise firing at maximum range.
• Cons: Close and mid-range assist performance is disastrous. If a lightweight AC is allowed to get close, you constantly face the risk of being unilaterally destroyed, unable to even lock on properly.
• Ideal Builds: Pure sniper builds with sniper rifles, equipped on high-hovering tetrapods or tank treads. Requires the skill to constantly utilize the map widely and secure optimal sniping points.

Missile Specialized Build

A style that primarily uses guided missiles to corner enemies with tricky barrages. FCS selection varies depending on the lock-on method.

FCS-G2/P10SLT

• Pros: Features high Missile Lock Correction, significantly reducing missile lock-on time for a single target. This improves missile cycle rate, allowing you to maintain continuous pressure.
• Cons: Assist performance for projectile weapons is generally low, making battles difficult if missiles run out or are intercepted.
• Ideal Builds: Effective in boss-fight builds that focus attacks on specific strong enemies using vertical missiles or high-tracking missiles.

FCS-G2/P12SML

• Pros: Specialized in Multi-Lock Correction, it truly shines when attacking multiple enemies simultaneously with weapons like split missiles. It exhibits tremendous effectiveness in missions with large numbers of weaker enemies.
• Cons: Single-target lock-on speed is inferior to the P10SLT. It's difficult to leverage its strengths in one-on-one situations, such as PvP.
• Ideal Builds: Builds that deploy multi-lock compatible missiles, for example, in missions to eliminate enemy Armored Core (AC) squads. The exhilaration is unparalleled.

Environmental Changes Since Regulation 1.07

Among past updates, Regulation 1.07's performance adjustment to IA-C01F: OCELLUS had a particularly significant impact on the FCS environment. Before the adjustment, it balanced excellent close-range aptitude with decent missile performance, making tactics involving missile pursuit during close-range combat extremely powerful. However, as a result of this update's substantial nerf to Missile Lock Correction, using it with missiles became difficult, solidifying its role as a pure infight-exclusive part. This change relatively increased the adoption value of FC-006 ABBOT and FC-008 TALBOT—which can handle close-to-mid range and missiles well—even for close-range builds that incorporate missiles, thus increasing the diversity of FCS choices.

Summary

FCS selection is a core and profound element of ARMORED CORE VI's Assembly / Build. As introduced in this article, each FCS has clear strengths and weaknesses. The shortcut to victory is first to clearly define how you want to fight and what your preferred combat range is.

• If you want to dominate close-range: IA-C01F: OCELLUS
• If you desire stable mid-range combat: FCS-G2/P05
• If you want to control from out-of-range: VE-21A
• If you want to unleash a rain of missiles: FCS-G2/P10SLT or FCS-G2/P12SML

Using these as a guideline, find the optimal "eyes" that match your weight, EN Load, and personal playstyle. We hope this helps you construct your ultimate Assembly / Build.