OS upgrades are one of the most important progression systems in Armored Core 6 after getting more parts and improving your AC. You unlock OS tuning alongside the Arena, and while its effects aren’t as immediately apparent as, say, equipping a big screw-off laser gun, dedicating the time to the mechanic will still dramatically improve how your gameplay goes. In this guide we’ll go over the five best OS upgrades that will always be useful, no matter what loadout.
Best OS Tuning Upgrades in Armored Core 6
Before we start, a quick disclaimer: If you want to actually tune your OS in Armored Core 6, you must beat Arena matches for the OS Chips they provide. And if you want to upgrade more than a few pieces of your AC’s OS, you’ll need to progress to at least rank D.
Depending on your skill and part availability, getting to rank D can be tough. Heck, getting past V. VI Maeterlinck in Rank 3 was probably my biggest hurdle. I had to pull out the dual shotguns and spend hours honing my skills to beat her. Once you do have enough OS Chips, you can start the process of OS Tuning.
Best Utility OS Upgrade: Boost Kick
Boost Kick is as simple as it sounds. You can press the Assault Boost activation button during an Assault Boost to stop short and deliver a swift kick. Not only does the attack cost no additional energy, it does a massive amount of stagger damage. If your opponent is already staggered, Boost Kick will do a good chunk of their health, as well. It’s not as effective a dedicated melee, and it’s certainly no where near a charged Pile Bunker hit, but if you’re rocking a gun in both hands, it’s a solid substitute for a melee weapon.
Best Activity-Specific OS Upgrades: Assault Armor and Terminal Armor
I’m cheating a bit here (and will do so again later), but whether you go with Assault Armor or Terminal Armor will heavily depend on which game mode you’re playing. In PvE, I highly recommend Terminal Armor, as it’s a single-use revive that activates when your AP hits 0 and pops a shield to give you a moment to breathe. If you’ve been hitting your head against one of AC6’s many bosses for a few hours, try popping on Terminal Armor and seeing if you can learn a bit more about the fight.
PvP players will gravitate more toward Assault Armor, as it’s a great “get away from me” button, and can be especially useful in the 3v3 mode. Popping Assault Armor in the middle of an ongoing fight might be disruptive for both sides, but if it puts your opponent into stagger, it might very well turn the tables. In a 1v1, it can have the same effect, but instead giving you a moment to breathe. If your enemy is already damaged, you’ll probably put them in to stagger, having the same basic effect.
Best Weapon-Specific OS Upgrades: Control Tuning
Here I go cheating again. The Control Tuning OS upgrades are incredibly powerful, especially at the higher upgrade levels. Which you choose will depend on the weapons you plan to use. Kinetic weapons like Shotguns, Linear Rifles, and Gattling Guns get tons of value from the Kinetic Control Tuning, and the same is true for the other options. Be sure you’re using all the same type of weapon, or you’ll need to invest in multiple Contro Tuning types.
Best DPS OS Upgrade: Direct Hit Modifier — Damage Tuning
Direct Hit damage is at the core of any DPS strategy in AC6, and the Direct Hit Modifier OS upgrade is a flat bonus to it. While 15% might not seem like too much, in a game where every bit of damage in the limited stagger window matters, it will come in absolutely clutch, especially in the late game. There’s really not much else to say about this OS upgrade. It’s just good.
Other Best Utility OS Upgrade: Weapon Bay
The Weapon Bay upgrade is probably the most utilitarian OS upgrade, allowing you to equip up to four different weapons from your left and right-hand slots. The upgrade is particularly useful for augmenting your left-hand weapon selection, as you can have both a melee and ranged weapon at the ready with the press of a button. You could also have two melee weapons, in one hand and a bazooka/pistol combo in the other, or any other combination you can think of.
You will have to sacrifice your back-mounted weapon options if you would prefer to swap between primaries, but ever with Weapon Bay equipped, you can still have your back weapons. It’s easy enough to swap between the two styles in the Assembly screen (though I recommend not equipping Weapon Bay if you don’t plan on using it).
Those are our five best OS upgrades in Armored Core 6. Which you choose will depend on your setup, and don’t be afraid to try out any of the ones we didn’t list here. There’s a good chance some of the other options can be just as effective for your playstyle. For more on the game, check out our guides on the Balteus boss, how to get more parts, and more in our AC6 guides hub.