Capture-the-flag (CTF) contests have been around for decades. One of the longest-running and more popular series began at the Vegas DEFCON show in 1996 and attracts thousands of participants. Running your own CTF contest can build security skills and help identify new internal and external talent. In this article for CSO Online, I compare CTFs with cyber ranges such as CyberGym (shown here) so you can learn what types of challenges you need to include for your own contest, how to make the contest run smoothly, and other logistics to consider.