The idea behind x33fcon (pronounced /ˈziːf-kɒn/) is to focus on a very specific need of the security industry: collaboration between blue and red teams (sometimes referred to as purple teaming). We know from our professional experience how hard it can be to build a solid bridge between those who assess security and those who guard the castle. Many misconceptions and misunderstandings arise between these two groups. We want to change that. Rather than continue to think about security from either an offensive or defensive perspective, our goal is to encourage security professionals to consider both perspectives while working more closely together. Both blue and red teams provide unique capabilities to an organization, but the collaboration between the two yields the best results.