The value of a penetration test is closely tied to how realistic the environment is—and in this episode, we examine the types of environments in which pen tests are conducted: known, partially known, and unknown. A known environment test, also called white-box testing, gives the tester full knowledge of systems, code, or architecture—allowing them to focus on deep technical vulnerabilities. In partially known or gray-box testing, the tester has limited information, simulating an internal threat or a moderately informed attacker. Unknown, or black-box testing, simulates an external attacker with no insider knowledge, relying on reconnaissance and brute-force discovery to find weak points. We discuss how each testing type serves different goals—technical validation, operational readiness, or exposure modeling—and how to select the right approach based on budget, risk, and maturity. The environment you choose defines what you learn—and how far your testers can go.