It’s also critical to know who’s in charge. Per FAR 61.47, the applicant for the rating will act as the pilot in command (PIC), not the examiner "unless the examiner agrees to act in that capacity". So even if it’s your initial pilot checkride (for the Recreational, Sport or Private Certificate), you’re in charge. Some examiners announce in their pre-exam briefing that they will take the role of PIC if any type of emergency were to arise. If your examiner doesn’t specify this, you should develop an emergency plan of action with the examiner. The checkride may be the first time you’ve met your examiner, so it is even more important that both of you understand what your roles should be in case of an emergency before you jump into the airplane.