ARC Raiders defensive PvP matchmaking test: what 1.39.0 changed

In July 2026, Embark began testing a change to its playstyle-based matchmaking: defending your squad would no longer move its playstyle estimate. The 1.39.0 notes said even knocking out the squad that attacked you would count as defence. This article records the test rule; check current official notes for any later change before relying on it in a live raid.

That is the whole of the change, and it is narrower than it sounds. It is also worth understanding precisely, because the part that still counts against you is the part most players run into by accident.

What the notes actually say#

Embark's matchmaking uses a playstyle estimate built from how you engage with other Raiders across previous rounds. Before 1.39.0, defending yourself fed into that estimate at a reduced weight. The update removes it entirely: only fights your squad chooses to start influence the estimate, and defending yourself has no influence at all.

Embark spells out the boundary. Your squad counts as defending when the other squad damages, downs or knocks out one of your squad first. Your squad counts as starting a fight when you strike first, weighted by how severe the encounter was. And joining a fight already in progress — third-partying — is treated as starting a fight, not defending.

The line that will catch people#

Third-partying is the clause worth reading twice. Embark says jumping into a fight already underway between other squads counts as starting a fight. Simply moving toward gunfire is not stated as a tracked event; the classification applies when your squad joins the encounter.

This is consistent rather than harsh. The change was aimed at players punished for outcomes they did not choose. A distant gunfight is not something happening to you until you decide it is.

What it does not change#

Two things worth separating out, because the update does not claim either.

The July rule did not itself specify any change to spawns, loot density or player counts. The estimate is an input to who you are grouped with, and Embark has been explicit elsewhere that similarity is likely rather than guaranteed and that shifts happen gradually. The notes do not quantify how much any individual round changes future lobbies.

It is also not a scoring system you can farm. Playstyle is described as a continuous spectrum, not a rank, and it exists to group players who are likely to have a similar kind of round. Playing artificially passively to chase a quieter bracket is optimising for a number you cannot see against a system that is designed to move slowly.

The behavioural change is small and real#

During the announced test, a defensive knock-out did not count as initiating PvP in the playstyle estimate. That might remove one reason a cautious Raider hesitated to return fire, though the notes do not measure player behaviour.

Use the rule as context for a fight already underway, while weighing the usual cost of taking it. Choosing to attack another squad, including joining its fight with a third party, was the behaviour Embark said would still count.

It is a test#

Embark described this as a testing period and said it would monitor metrics and player feedback. The cited announcement does not say when the test ended or whether the zero-weight rule was later made permanent. Treat current game behaviour as unverified here until Embark provides a newer confirmation.

The rest of 1.39.0 is smaller: Seeker and Wolfpack Grenades no longer deal inconsistent damage, trinkets from the Converging Paths project now stack, Dam Battlegrounds and Buried City picked up collision and stuck-spot fixes, and footstep audio in water was improved. That last one is not a matchmaking change, but if you rely on water to move quietly, it is the line in these notes most likely to change a run.