Red team vs blue team vs purple team: what each one really does

Short answer: the red team emulates a real attacker to test whether the organisation detects and responds; the blue team defends, detects and responds; the purple team is the two working in the same room so that every attack produces a detection rule. Red teams are glamorous and rare. Blue teams are where most jobs and most learning are.

The colour metaphor is borrowed from military exercises, and it survives because it captures something real: an organisation only knows how good its defences are when someone with permission tries to defeat them.

What the red team does

A red team emulates a specific adversary against a live organisation, with objectives rather than a checklist: reach this data, move money, gain domain administrator without being caught. The engagement is measured in weeks, and the point is not the vulnerability list.

The point is the detection. A red team engagement answers questions no vulnerability scan can: did anyone notice the initial access? How long did we have before someone reacted? Did the response actually contain us, or just make noise?

That is why a red team report reads differently from a pentest report. It contains a timeline. Each step is annotated with what the defenders saw, or did not see.

The tradecraft matches the objective — quiet infrastructure, patient movement, operational security throughout, which is the substance of Red Team Operations and OPSEC & Evasion.

How that differs from a penetration test

	Penetration test	Red team engagement
Goal	Find and document as many vulnerabilities as possible	Achieve an objective, and measure detection
Duration	Days to two weeks	Three weeks to three months
Scope	Defined systems, known to the defenders	Broad, often unannounced to most staff
Noise	Acceptable — speed matters	Avoided — being caught is a finding
Deliverable	Findings, severity, remediation	Attack narrative, timeline, detection gaps
Who benefits	Teams fixing specific flaws	Organisations testing their response capability

An organisation that has never had a penetration test should not buy a red team engagement. Emulating a sophisticated adversary against an environment with unpatched perimeter services tells everyone something they already knew, expensively. Pentest first, fix, then test the response.

What the blue team does

Everything that keeps the organisation running while people are actively trying to break in: architecture and segmentation, hardening, patching, identity management, logging that is actually useful, detection engineering, threat hunting, and incident response when it fails anyway.

Two things about blue work are chronically underrated by beginners:

It is harder than attacking. An attacker needs one path. A defender needs to cover all of them, with a budget, under a change freeze, without breaking production.

It teaches attacking faster. Nothing improves an operator's tradecraft like having watched an environment from the inside and knowing which of their actions generate a log entry. This is why the free Infrastructure Defense course sits alongside the offensive catalogue rather than apart from it — segmentation, hardening, useful logging, detection rules and response drills against real attacker behaviour.

What purple teaming actually means

Not a third team. A working arrangement: the red operators and the defenders in the same room, running attack techniques deliberately while the defenders watch their own telemetry and build detections in real time.

The loop is simple and it is the highest-value security exercise most organisations can run:

1. Pick a technique — say, Kerberoasting, or credential dumping from LSASS.
2. Execute it in a controlled way.
3. Ask the defenders what they saw. Usually: nothing, at first.
4. Find the telemetry that would have shown it.
5. Write the detection, tune it, verify it fires and does not drown anyone in false positives.
6. Next technique.

A week of that produces more measurable security improvement than a stealthy engagement whose finding is "we were not detected". The MITRE ATT&CK framework exists largely to give both sides a shared vocabulary for step one.

Which pays more?

Red team roles pay more per position at senior level and are far scarcer. Blue team roles are plentiful, span every industry, and reach comparable numbers at the top of detection engineering and incident response — a strong detection engineer is harder to replace than a strong operator, and salaries have begun reflecting that.

Rough North American ranges: SOC analyst entry 65,000 to 85,000 US dollars, experienced detection engineer 110,000 to 150,000, penetration tester 70,000 to 135,000 across the levels, senior red team operator 140,000 to 190,000 plus. Consulting pays less than product companies at the start and teaches considerably more.

Which side should you start on?

If you can choose freely and you want offensive work eventually, start blue. Two years in a SOC or on an infrastructure team gives you three things no course provides: how organisations actually behave, what telemetry exists, and why the obvious fix is not applied. Attackers who have that context write findings that get acted on.

If you are already technical and impatient, start with penetration testing, not red teaming. Junior red team positions barely exist; operators are almost always people who tested for several years first. The path in order:

1. Foundations — networking, Linux, Windows and Active Directory. See how to become a penetration tester for the sequence and timings.
2. Methodology, through a full engagement cycle. The free penetration testing course runs from scoping to the client report.
3. Domain depth — Active Directory Attacks, because that is where internal engagements are decided.
4. Detection literacy — Infrastructure Defense, free, and the thing that separates an operator from a script runner.
5. Only then, tradecraft — Red Team Operations.

Frequently asked questions

What is the difference between a red team and a penetration test?

A penetration test finds and documents as many vulnerabilities as possible in a defined scope, over days. A red team engagement pursues an objective over weeks while staying undetected, and measures whether the defenders notice and respond. One tests the systems, the other tests the security team.

What does a purple team do?

It is not a separate team but a working session: attackers execute known techniques while defenders watch their telemetry and build detections on the spot. The output is tuned detection rules rather than a report, and it usually improves security faster than a stealthy engagement.

Is blue team harder than red team?

In one important sense, yes: an attacker needs one working path, a defender has to cover all of them, with a budget and without breaking production. Defensive work is also less visible, which is why it is underrated by beginners and valued by employers. The infrastructure defence course is free with an account.

Should I start in red team or blue team?

Blue, if you can. Two years defending teaches how organisations really work, what telemetry exists and why fixes stall — context that makes offensive findings actionable. Junior red team roles barely exist; most operators spent years doing penetration testing first.

Does red team pay more than blue team?

Per position at senior level, usually yes, but the roles are far rarer. Detection engineering and incident response reach comparable pay at the top and offer many more openings across every industry, so total career expectancy is not obviously better on the offensive side.

What is MITRE ATT&CK used for?

It is a catalogue of adversary techniques observed in the wild, and it gives red and blue teams a shared vocabulary. Red teams use it to plan realistic emulation, blue teams to measure detection coverage technique by technique, which is what makes purple team sessions measurable.

Where to go next

Whichever side attracts you, the first year is the same: foundations, then a full engagement cycle. Start with the free penetration testing course, add Infrastructure Defense to see your own attacks from the defender's console, and use the roadmap to decide what comes after.