How do I prepare for HR round questions — what are they actually testing?

It's a formality until it isn't. HR rounds reject for three real reasons: red flags (badmouthing past employers, dishonesty, wildly misaligned salary expectations), retention risk (signals you'll leave in six months), and team fit concerns escalated from earlier rounds. Prepare five stories, not fifty answers — one each for: a conflict you resolved, a failure and what changed after it, something you're proud of, why you're leaving/choosing this company, and where you're headed. Every behavioral question is one of these wearing a costume. Structure each as situation → what YOU did → result (STAR, but casual). The traps: 'Why should we hire you?' wants specifics matched to the JD, not adjectives. 'Weakness?' wants a real one plus the system you built around it. Salary: give a researched range, never 'as per company norms.' And have a real answer for 'any questions?' — nothing is also a signal.