ARC Raiders: How to Farm Flashpoint Materials for High-Gain Antenna – Close Scrutiny Guide

The Short Version: Live in Close Scrutiny and Hunt High-Tier Arcs

If you want to finish the High-Gain Antenna project fast, you should be doing almost all of your farming in Close Scrutiny zones and prioritising high-tier Arc machines. Close Scrutiny boosts Arc material drops across the board, spawns Vaporizers and Surveyors more often, and – crucially – puts Assessor pods on the map for Assessor Matrices.

Once I stopped doing “normal” contracts and instead chased Close Scrutiny rotations, the whole project went from feeling impossible to “okay, this is just a grind I can plan around.” The loop that worked was:

• Only deploy into maps with the Close Scrutiny condition active
• Build Stage 1 around Bastion kills for maximum material overlap
• Pre-farm Stage 2 and 3 drops (Vaporizer Regulators, Assessor Matrices, Surveyor Vaults, Arc Synthetic Resin) any time they show up, even before you need them
• Extract early and often – a successful bank of materials beats a greedy wipe

Understanding Close Scrutiny (The Core of the Grind)

Close Scrutiny is a map condition that ramps up Arc activity. When it’s on a zone, you’ll see:

• More and tougher Arc patrols in general
• Frequent spawns of Surveyors and Vaporizers
• Assessor drop pods touching down somewhere on the map
• Increased chance for Arc-specific materials to drop (Arc Flex Rubber, Arc Performance Steel, etc.)

I wasted a lot of time doing comfy contracts with no map condition, wondering why my inventory barely moved. Once I committed to only playing when Close Scrutiny was active on a reasonably open map, the High-Gain Antenna bar actually started to tick in noticeable chunks.

From the deployment screen, hover over zones and check the modifiers. If none have Close Scrutiny, it’s honestly worth doing something else for 10 minutes and checking again rather than running low-efficiency missions.

Stage 1: Bastion-Centric Farming for Core Materials

Stage 1 needs a pile of generic Arc materials like Arc Alloy, Arc Flex Rubber, Arc Performance Steel and Advanced Arc Powercells. You can get these from lots of Arc enemies, but Bastions are by far the best overlap target.

Every Bastion kill in a Close Scrutiny map has a good chance to spit out multiple of the things you need simultaneously. My typical Stage 1 loop looked like this:

• Pick an open map with Close Scrutiny active (easier to kite Bastions and their escorts)
• On deployment, open your map and mark any Bastion or large Arc cluster icons
• Move between Bastions first, contracts second – treat contracts as incidental, not your main objective
• Wipe the entire pack (Sentinels, Leapers, Bombardiers) to rake in extra Arc Flex Rubber rolls

The breakthrough for me was mentally demoting contracts to “side quests”. The real mission is clearing Arc elites. If a contract pulls you away from a Bastion ping, skip the contract and go for the Bastion instead; the time-to-reward ratio is simply better for Antenna progress.

Two common mistakes I made here:

• Tunnelling on weak mobs. Ticks and lone Sentinels are not worth chasing unless they’re glued to a Bastion pack. Focus the elites.
• Overstaying on one hot zone. If you burn through a Bastion and its escorts, move on. Respawns aren’t fast enough to justify circling the same site.

Arc Flex Rubber: Squeezing It Out of Every Fight

Arc Flex Rubber is the Stage 1 bottleneck for a lot of players. It has a lower drop rate than the basic stuff and mainly comes from higher-tier machines: Bastions, Sentinels, Leapers, Bombardiers, and the really nasty queens/matriarchs.

The way I improved my Flex Rubber flow was:

• Never leaving Arc packs half-dead – finishing off the escorts gives extra Flex Rubber chances
• Fighting near cover so we could safely loot mid-engagement, then reposition
• Stacking Close Scrutiny + Arc-heavy zones whenever possible, even if the contract rewards elsewhere looked nicer

If you’re close to done with Stage 1 but still short on Flex Rubber, do one or two dedicated “flex runs”: ignore everything that isn’t a Bastion or a chunky Arc patrol, and bail the second your backpack looks healthy. It’s better to extract three times with small hauls than once with a backpack you never bank because you got greedy and wiped.

Pre-Farming Stage 2: Vaporizer Regulators and Assessor Matrix

Stage 2 is where people really stall, mostly because of Vaporizer Regulators and Assessor Matrices. The trick is to start collecting these long before you finish Stage 1, while you’re already running Close Scrutiny for Bastions.

Killing Vaporizers Safely for Regulators

Vaporizers are high-threat Arc units introduced with the Flashpoint update. They hit hard and behave erratically, but they’re the only reliable source of Vaporizer Regulators.

• Fight them in open terrain where you can see their windups
• Bring at least one burst DPS weapon (shotguns, high-damage rifles) to punish openings
• Have someone on CC / disruption duty – grenades, stuns, or EMP effects make a big difference
• Prioritise them in any pack; the longer they live, the messier the fight gets

When I stopped treating Vaporizers as “just another elite” and started hard-focusing them first, our death rate in Close Scrutiny maps collapsed, and so did the regulator drought.

Assessor Matrices: Never Ignore a Drop Pod

Assessor Matrices are the other big hurdle. They only come from Assessor drop pods that appear when Close Scrutiny is active. These events are easy to miss if you’re tunnel-visioned on contracts.

What I watch and listen for:

• A distinctive drop-pod whine or impact sound somewhere in the zone
• A new objective marker or icon on the map indicating an Arc device or pod
• Radio/VO hinting at “unusual Arc activity” or “incoming pod”

As soon as a pod appears, I mark it and route the squad there, even if we’re mid-contract. The event usually plays out as:

• Reach the pod and deal with defending Arc forces
• Survive while the Assessor device is “breaching” or powering up
• Destroy or interact with the device once it’s vulnerable and loot the remains for a chance at Assessor Matrix

The key is to not let the event time out or ignore it; every missed pod is potentially a Matrix you’ll have to grind for later. I started treating Assessors as the absolute priority event in any Close Scrutiny run, and by the time I unlocked Stage 2 I already had over half the Matrices banked.

Stage 3 Prep: Surveyor Vaults and Arc Synthetic Resin

Stage 3 leans heavily on Surveyor Vaults and Arc Synthetic Resin. You can quietly stockpile both while you’re working on the earlier stages if you know what to look for.

Surveyors – Double-Duty Targets

Surveyors are great value: each kill can give you Surveyor Vault progress and also drop Arc Performance Steel, which loops back into Stage 1 materials if you still need some.

• In Close Scrutiny maps, Surveyors tend to show up more often and with heavier escorts
• Use accurate mid-range weapons to snap them out of the air quickly
• Clear the entire escort so you have time to loot without being sniped or rushed

I got into the habit of always diverting to kill a Surveyor if it was reasonably close to our path. Even when I was technically “on Stage 1,” those early Vaults took a lot of pressure off Stage 3 later.

Shredders and Arc Synthetic Resin

With the Flashpoint update, Shredders became the main source of Arc Synthetic Resin and they spawn more broadly across maps. They’re nasty in tight spaces but much more manageable on open terrain.

• Prefer open-field encounters where you can kite their attacks
• Don’t stack up – spread out so one attack doesn’t chunk the whole team
• Focus fire one Shredder at a time to quickly reduce incoming damage

On runs where we knew Resin was the goal, we’d pick an open Close Scrutiny map, roam for Shredder pings and large Arc patrols, and then extract as soon as our packs looked decent. Trying to chain three or four fights in a row with Shredders almost always ended in a wipe for us.

Squad Setup and Extraction Discipline

Your build matters less than your discipline, but there are a few things that helped our Flashpoint farming runs feel consistent instead of stressful roulette:

• One tanky frontliner to keep Bastions, Vaporizers and Shredders facing the same direction
• One high burst DPS who can delete priority targets during openings
• One utility/support bringing stuns, slows, or shields plus extra heals
• Plenty of grenades or explosives for shredding clustered Arc escorts

On extraction, my personal rule is: the moment we’ve banked at least one “rare” for each of the current problem materials (Flex Rubber early, Regulators/Matrices later), I start looking for the nearest safe evac instead of “one more fight.” The upgrade menu doesn’t care how stylish your last fight was; it only cares what you actually extracted with.

If you stick to Close Scrutiny maps, hunt Bastions first, never ignore Assessor pods or Surveyors, and treat Vaporizers and Shredders as high-priority threats instead of background noise, the High-Gain Antenna grind turns into a predictable route instead of a frustrating lottery.