If you don’t pass an exam, you may retake it. You need to register again for retake attempts, and either pay full price or use a coupon or voucher. If you don’t pass, you need to wait for at least two weeks for taking the exam again.
A candidate may try any exam for a maximum of three times. A fourth attempt requires a waiver from the Acquia Certification Program office. If you don’t pass an exam, you’ll get an email with your score.