ENISA released a report addressing the contemporary use of Capture-The-Flag (CTF) competitions around the world. It explores how these competitions work and provides a high-level analysis of the dataset of the most recent major public events. Based on the results of the findings, the report suggests recommendations for consideration in the design phase of these types of competitions. The study comes as a complement to the Capture-the-Flag events co-organized by ENISA and the European Commission such as the European Cybersecurity Challenge (ECSC)
Source: https://www.helpnetsecurity.com/2021/05/18/all-you-need-to-know-ctf-competitions/