# Capture the Flag **Domain:** Cybersecurity training **Doc Type:** Developed Practice Node **Maturity:** Developed **Collection:** [[collections/Gamification|Gamification Collection]] ## Definition A cybersecurity **capture the flag (CTF)** is a structured competition in which participants solve security challenges or attack and defend systems to obtain proof tokens called flags. Formats include jeopardy-style problem sets and live attack-defense environments. ## Significance CTFs make adversarial skill observable and consequential: a vulnerability is actually found, a system is actually compromised within authorization, and performance can route participants into teams, jobs, or research. They therefore combine [[wiki/Costly Signaling|costly signaling]], training, recruitment, and bounded attack. ## Boundary Authorization is decisive. The same technical action outside the contest scope may be unlawful or harmful. ## Sources - [Cybersecurity Knowledge and Skills Taught in Capture the Flag Challenges](https://arxiv.org/abs/2101.01421) ## Routes [[wiki/Bug Bounty|Bug Bounty]] · [[wiki/Red Teaming|Red Teaming]] · [[wiki/Non-Substitutability|Non-Substitutability]]