This document discusses a social engineering contest called SECTF that takes place at DEF CON. It provides lessons learned from running the contest over 5 years. The contest involves contestants attempting to obtain sensitive information from large companies through vishing (voice phishing) calls. The document outlines themes and successes from past years, noting that companies remain vulnerable to social engineering attacks and even implausible pretexts can be successful. It encourages attending DEF CON to learn more about the upcoming contest.