ARC Raiders Detection: Scanner Colors and How to Stay Unseen

Blue, yellow and red scanner lights tell you exactly what an ARC machine knows. What alerts them, what does not, and the stealth routine that keeps you unseen.

Category: Arc Raiders AI & ARC Machines · Updated 2026-08-03

Every ARC machine tells you what it knows. The scanner beam is the readout, and reading it correctly is the difference between walking past a patrol and getting shot through a window.

The three scanner colors

The community wiki's ARC page lists three behavior modes, each with its own scanner color:

• Blue. Unelevated patrol. Passively searching for Raider targets or activity, and it keeps patrolling until it detects a disturbance.
• Yellow. Alerted. It witnessed possible Raider activity, it will investigate that location, and it lowers its alert level again if it finds nothing.
• Red. Combat. It has found a target and will attack until it loses that target.

Two caveats from the same page matter more than the list. A machine on patrol can skip yellow entirely: attack it and it goes straight to red, because no investigation is needed to find you. And the beam shifts between red and yellow as Raiders enter and leave scanner range, so a color that keeps switching is you crossing the edge of its reach.

Treat the drawn beam as an honest readout of that reach. Embark has patched a Sentinel laser for being shorter than its sight range, and again for not reaching a targeted player at distance. A beam that undersells what the machine can see gets fixed as a bug.

Not every colored beam is a state light

Several machines fire warm-colored targeting lasers that mean "about to shoot," not "cautious." A Rocketeer aims four yellow lasers that turn red a moment before its missiles fire. A Sentinel tracks you with a thick orange laser, then converges several beams just before shooting, and the wiki calls that beam orange in one place and yellow in another, so go by behavior: converging beams mean incoming. Wasps and Hornets both paint their target with a red laser on entering combat, before firing.

It runs the other way too. An ARC Surveyor fires a blue laser skyward to talk to orbit, and a Snitch's spotlight is a search beam.

Free intel: a machine glowing yellow or red while aimed away has probably found another player.

They cannot hear your voice

Proximity voice chat is a real system, with its own mode setting, push to talk bind and volume slider, separate from party chat. Other Raiders hear you through it. The machines do not.

Reporting on the ARC's design says that even though players hear each other speaking, the ARC cannot hear speech, and cannot hear emote voice lines either, including the ones that shout "Don't shoot!" Every reply in the Steam forum thread asking the same question says no. The most detailed of them describes ARC hearing as selective: it registers running and gunfire to some degree, and does not react to voice or emotes. That is one outlet plus player testing, not a developer statement, and no counter-source has surfaced.

Do not stretch that into "any noise my Raider makes is free." Pinging on your screen or map plays a radio callout enemies can hear. The exemption is your actual voice.

What actually alerts them

Documented, or consistently reported by players:

• Gunfire. Guns are recorded at multiple distances on purpose, and silencers exist to shrink how far the crack carries.
• Footsteps. Five distinct volume tiers: standing still, walking, crouching, running, sprinting.
• Your backpack. Embark's audio blog says it changes sound based on how full it is. A loaded Raider is a louder Raider.
• Breaching anything. Doors, containers, all of it. Loud enough that a whole skill, Gentle Pressure, exists to shrink the radius.
• A machine in distress. A breached ARC Probe beeps loudly to signal nearby ARC, and a Snitch that spots you alerts them and calls in reinforcements.
• Birds. They scatter as you approach, which alerts both Raiders and nearby ARC.
• The extraction elevator. About 45 seconds to arrive, and the noise draws ARC, predators and players.
• Standing in the forward scanner cone. Player testing says almost all ARC have one, covering a cone in front of them for quite some distance.

Hold these loosely: a bullet flying past a machine, and sprinting across its line of sight, are plausible triggers named in one article and nowhere else. That article also claims metal detectors and motion sensors alert ARC, which we could not corroborate anywhere.

Geometry matters more than it used to. A 2026 patch sharpened how ARC hear outdoors while cutting their sensitivity indoors and through geometry, made foliage granular so Raiders at the edge of cover are easier to spot than those deep inside it, and made ARC less perceptive of freshly spawned Raiders.

Where the community disagrees

Said plainly, rather than repeating invented numbers.

• Vision cone. No agreed figure, and the degree numbers on guide sites have no testing behind them. Only the qualitative version holds: narrow, forward-facing, and blind to the machine's sides, below it, and through terrain.
• Hearing radius. No source of any quality gives one for ARC. The only estimates that exist are player hearing player, they span a rough spread rather than a figure, from quite short outdoors up to considerably further at a sprint, and players report sound carrying further indoors than out.
• Whether crouching shrinks detection range. Unconfirmed. It is a quieter movement tier, and it helps you slip patrols in cover, but nothing supports it shrinking a detection radius as its own mechanic.
• Whether they track you through walls once red. Disputed. One camp says a red machine knows where everyone nearby is, another says breaking line of sight starts a de-aggro timer within seconds, a third thinks patrol routes just cross where players were. Nothing settles it.
• Whether grenade explosions alert them. One tester reported ARC ignoring his impact grenades and investigating where he threw them from instead. Unrepeated, and an open question.

The stealth routine

Worth learning properly, because it keeps working. Embark's machine learning research lead has said the machine learning here is strictly for locomotion, foot placement and movement, while decisions about where to go run on behavior trees. They do not adapt to you between raids.

1. Bind Walk. Walk (Toggle) defaults to V on PC, Walk (Hold) is unassigned out of the box. Crouch and walk are separate noise tiers, and most players only ever use one of them.
2. Carry less. A fuller backpack is louder, you move faster carrying nothing, and stamina regenerates faster while still or crouched.
3. Go deep, not near. The edge of cover is where you get spotted. Push all the way into the foliage or the building, and prefer indoors, where ARC are less sensitive to sound.
4. Hold still in the bushes. The wiki hedges deliberately: heavy foliage "may" be enough to avoid a Snitch scanner. A strong bet, not a guarantee.
5. Know your own tells. A critically hurt Raider makes pained noises while hiding. The Suffer In Silence skill quiets that, Silent Scavenger quiets looting.

Break line of sight, or hold still?

It depends which sense flagged you, because the two have opposite counters.

Sight is a forward cone with hard geometry limits. Player testing holds that your movement state does not change whether you are seen, only line of sight does, though that is forum testing rather than a documented rule. If a machine has eyes on you, move: put a wall, a floor, or a hill between you and its front.

Sound is omnidirectional but attenuated by geometry. If something heard you, more noise is what keeps it coming. Stop, let the investigation run at the spot it is headed for, and relocate only when you can do it silently.

Either way, do not stop at the wall. A Turret fires at your last known location for a short time after you break line of sight, and a Sentinel whose lasers converge after you leave fires at where you were. Windows and open doorways are not cover.

The window before red

Yellow is an investigation, and investigations expire. That is your window.

The only measured de-escalation on the wiki is the Rocketeer: roughly 20 seconds in red once you hide, then roughly 20 seconds in yellow, then blue, thrusters straightening as it settles. Do not generalize it: no source gives timings for any other machine.

The Snitch gives you a countable window instead of a timed one. Reinforcements are only guaranteed once it begins the third call in its series, and a few well-placed shots of medium or heavy ammo usually kill it first. A Lure Grenade will not interrupt a call, that was patched out. Even a completed call is survivable by player accounts: reinforcements arrive not knowing where you are, searching around the call.

Disengage instead of fighting

• Run and hide inside a building. They eventually lose interest and resume patrol.
• Do not take on more than one at a time.
• Smoke Grenades last 20 seconds and block visibility from ARC and Raiders. Li'l Smoke lasts 6 seconds with a much smaller cloud.
• A Lure Grenade sticks to surfaces or machines, pulls ARC from a long way off and draws their fire for 15 seconds. Enough to escape a persistent Wasp or Hornet swarm.
• Going down ends the ARC fight. ARC will not target a downed Raider, and you can crawl for about a minute, activate an extraction, or reach a Raider Hatch. Other Raiders will still finish you.

<!-- CORRECTED FAQ. Replace the page's faq array with the entries below. Only entries 2, 5 and 6 changed. -->

```json

[

{

"q": "What do the scanner colors mean in ARC Raiders?",

"a": "Blue means the ARC machine is on an unelevated patrol, passively searching. Yellow means it is alerted and heading to investigate a disturbance, and it lowers its alert level again if it finds nothing. Red means it has found a target and is in combat until it loses that target. Two exceptions matter: a machine you attack while it is patrolling can skip yellow and go straight to red, and the beam flickers between red and yellow as you cross in and out of its scanner range."

},

{

"q": "Can ARC machines hear you talking in proximity chat?",

"a": "No. Other Raiders hear your proximity voice chat, but the ARC do not register speech, and they do not react to emote voice lines either, including the ones that shout things like 'Don't shoot!'. Their detection runs on scripted noises and visual cues instead, mainly gunfire, footsteps, and being inside their forward scanner cone. One caveat: pinging something on your screen or the map plays a radio callout that enemies can hear, so it is your voice specifically that is free, not every sound you make."

},

{

"q": "What alerts ARC machines in ARC Raiders?",

"a": "Gunfire, footsteps, breaching doors or containers, and standing in the forward scanner cone are the reliable ones. Footsteps have five separate volume tiers (standing still, walking, crouching, running, sprinting), a fuller backpack makes you louder, birds scattering as you pass alerts nearby ARC, a breached ARC Probe beeps for help, a Snitch that spots you calls in reinforcements, and the extraction elevator takes about 45 seconds to arrive while making noise the whole time. Your voice is the exception: ARC do not hear player speech or emote voice lines."

},

{

"q": "How do you lose ARC aggro in ARC Raiders?",

"a": "Break line of sight and keep moving. Machines fire at your last known position for a short time after you disappear, and they shoot through windows and open doorways, so the first wall you reach is not safe by itself. Hiding inside a building works, because they eventually lose interest and resume patrolling. The only de-escalation timing documented on the wiki is for the Rocketeer, roughly 20 seconds in red and then roughly 20 seconds in yellow before it returns to blue, and no source gives those numbers for any other machine."

},

{

"q": "Does crouching make you harder for ARC to detect?",

"a": "Crouching is quieter, yes. Embark's patch notes list five separate movement noise tiers (standing still, walking, crouching, running, sprinting), and crouching in cover is the standard way to slip a patrol route. But no source confirms the popular claim that crouching shrinks an ARC's detection range as its own mechanic. Player testing holds that being seen comes down to line of sight rather than movement state, so crouching is unlikely to hide you from a machine that already has you in its forward scanner cone."

},

{

"q": "How far can ARC machines see and hear in ARC Raiders?",

"a": "Nobody has pinned down a number, and the figures circulating on guide sites have no testing behind them. What is consistently reported is qualitative: the vision cone is narrow and forward-facing, and machines cannot see to their sides, below themselves, or through terrain. No source of any quality gives an ARC hearing radius, and the only distance estimates that exist are players judging other players, running from quite short outdoors up to considerably further at a sprint, with sound reported to carry further indoors than out. In practice: get out of the front of the machine, put solid geometry between you and it, and stop making noise."

},

{

"q": "Do ARC machines see through walls once they aggro?",

"a": "The community disagrees and nothing settles it. One camp says a machine in red knows where every nearby player is, another says breaking line of sight starts a de-aggro timer within seconds, and a third thinks patrol routes simply happen to cross where players have been. Embark has shipped patches reducing how well ARC perceive sound passing through geometry, which argues against the wallhack reading. Play it as though breaking line of sight works, because it demonstrably lets players escape, but expect fire at your last known position for a moment after you vanish."

}

]

```