About

x3CTF is a cute little jeopardy-style CTF with web, pwn, rev, crypto, and misc challs!

x3CTF 2025 (feat. mvm) will run from Jan 24th 18:00 UTC until Jan 26th 18:00 UTC (48h). Be here a few minutes early for a fun surprise ^_^.

Check us out on CTFtime and join our Discord server.

Signups

Sign up by simply registering an account for your team above, one account per team ;3.

MVM

We teamed up with mvm to accept community-submitted challenges for x3CTF. Challenge submissions have now been now closed, thank you for all the awesome contributions!

Prizes

List of prizes:

• iPad
• iPod
• iPhone
• Android phone for every person on the team (while supplies last)
• Thinkpad (with socks and cat ears)

Prizes will be signed.

Each winning team will be able to pick one prize in scoreboard order. There will probably be alternate prizes for those who can't or wish not to receive a prize physically.

We reserve the right to not send out a physical prize if shipping it would be prohibitively difficult or expensive (shipping costs over 50€ will be decided on a case-by-case basis).

We also have a Windows Phone and we honestly have no idea what to do with it.

Rules

1. You are allowed to play either individually or with a team. When playing with a team, register and use a single account for the entire team.
   
   1. If playing on a team, you are allowed to also have 1 personal account to yourself, but you are not allowed to submit flags on it.
2. There is no bruteforce or scanning of public infrastructure required to solve the challenges.
3. Attacking or abusing the organizers infrastructure is forbidden.
   Valid challenge targets are located at:
   
   1. https://<UUID>.x3c.tf​:1337
   2. https://<UUID>.x3c.tf​:31337
   3. instances.x3c.tf:30000-65535 (tcp/udp)
4. Don't share flags or discuss challenges outside of your team while the CTF is running.
   
   1. You are, of course, allowed to discuss the challenges and share solutions once the CTF has ended.
5. Community challenge authors (mvm) are allowed to participate in the CTF and even solve their own challenges. However, they (and their team) are not allowed first blood the challenges they contributed - they must wait for a different team to solve the challenge first.
6. Have fun!
   
   1. Let others have fun too! We're an inclusive CTF and discrimination or harassment will not be tolerated.

Note: The rules are still being determined and may change before the CTF begins.

Credits

The x3CTF team consists of Coderion, DagurB, Raptor, rdx4.2, Rebane, and ShadowCone.
We're using the Berg CTF Platform by NoRelect, with a custom frontend by Rebane.
Thank you to all the MVM contributors for submitting additional challenges: alex_hcsc, boxmein, hackrrr, joneswastaken, ksaweryr, musava_ribica, natan.p, and xtea418.
Music: ??? (surprise!)