The rules of engagement define the scope, objectives, methodology, deliverables, and limitations of the penetration testing. They also specify the legal and ethical boundaries, communication channels, and escalation procedures. Establishing the rules of engagement is the first step when planning to conduct penetration testing for a client, as it ensures that both parties agree on the expectations and outcomes of the testing. The other options are important steps, but they should be done after the rules of engagement are established. References: CISA Review Manual (Digital Version) 1, page 381.