How to Host a CTF

1. Understand the CTF formats

Before you plan anything, decide what kind of event you want to run. The two common formats are:

• Jeopardy: Challenges are grouped by category (web, forensics, cryptography, and so on) and point value. Participants solve them in any order. This is the easiest format to host and the best choice for most college and corporate events.
• Attack-Defense: Teams are given identical vulnerable systems to patch and defend while attacking others. It is more complex to run and better suited to advanced audiences.

For a first event, a Jeopardy-style CTF is almost always the right call.

2. Define your goals and audience

Clarify why you are running the event and who it is for. Your goals shape difficulty, categories and duration.

• Learning: Reinforce a course or module with guided, beginner-friendly challenges.
• Competition: An inter-collegiate or tech-fest event that rewards top talent on a public leaderboard.
• Recruitment: A hiring or internship pipeline where solve data helps you identify strong candidates.

Match difficulty to your audience. A mixed field of beginners and experienced players needs a spread of easy, medium and hard challenges so everyone stays engaged.

3. Choose a format, size and duration

Decide the practical shape of the event:

• Individual vs team: Teams encourage collaboration and scale to larger crowds; individual play makes assessment cleaner.
• Participant count: Plan infrastructure for your expected numbers. A campus event might be 25 to 100 players; a flagship fest can be several hundred.
• Duration: Short sprints of 4 to 8 hours suit a single-day fest. Multi-day events of 24 to 72 hours give participants flexibility and raise engagement.

4. Pick your platform

You have two broad options for the scoring and delivery platform:

Self-hosted (open source)

Open-source scoreboards such as CTFd let you run the event on your own infrastructure. This gives you full control but means you handle servers, challenge hosting, uptime, security and live support yourself. It is a good fit if you have a strong technical team and time to prepare.

Managed CTF-as-a-Service

A managed service hosts the platform, builds the challenges, runs the live scoreboard and provides support during the event, so your team can focus on participants. This removes the infrastructure and reliability burden, which is why most institutions choose it for high-visibility events. Nexix offers a fully-managed option: see CTF-as-a-Service.

5. Create or source your challenges

Challenges are the heart of a CTF. Aim for a balanced spread across categories and difficulty:

• Web exploitation such as injection, authentication and access-control flaws
• Forensics such as packet capture, disk and memory analysis
• Reverse engineering of binaries and scripts
• Cryptography from classical ciphers to modern weaknesses
• OSINT and miscellaneous puzzles for accessible entry points

Every challenge needs a clearly defined flag, a tested solution path and, ideally, a hint system so beginners are not stuck. Test each challenge on a fresh environment before the event to confirm the flag validates correctly.

6. Set up scoring and the scoreboard

Configure point values (often higher for harder challenges), decide whether to use dynamic scoring that decays as more people solve a challenge, and make sure the live scoreboard is visible to all participants. A real-time leaderboard is a big part of what makes a CTF exciting.

7. Run the event

On the day, the priorities are stability and support:

• Open registration early and confirm every participant can log in
• Monitor infrastructure and challenge health throughout
• Staff a support channel for stuck players and technical issues
• Release hints or additional challenges on a schedule to maintain momentum

8. Wrap up and report

After the flags stop, close the scoreboard and share results. A good post-event package includes participation statistics, challenge solve rates, top performers and engagement metrics, plus digital certificates for participants and winners. For recruitment or academic events, this data is often as valuable as the event itself.

Quick checklist

• Format chosen (Jeopardy or Attack-Defense)
• Goals, audience and difficulty defined
• Size, team structure and duration set
• Platform selected (self-hosted or managed)
• Challenges built, tested and balanced across categories
• Scoring and live scoreboard configured
• Support and monitoring plan in place
• Post-event reporting and certificates ready