mezzacotta Puzzle Competition

Welcome to the mezzacotta Puzzle Competition!

This competition involves solving 25 puzzles plus a metapuzzle over a period of a week, during which new puzzles are released daily. The puzzles come with no instructions provided, and are intended to be solved by teams of up to 5 people. The top teams, from anywhere in the world, will win prizes. See the rules for full details.


13 May 2020
We have uploaded a mirror archive of the now defunct CiSRA Puzzle Competition website. This was a puzzle comp that we organised from 2007 to 2013. The original website is gone, but we have saved a snapshot copy of the archived competitions, complete with all of the puzzles, solutions, and team standings.

14 October 2017
Sorry for the lack of updates! We've fallen too far behind in new puzzle creation to run a competition in 2017, but we hope to run one in the first half of 2018. If you're desperate for puzzles, you might enjoy reading our webcomic, Eavesdropper (start reading here)...

26 January 2017
Oops! We forgot to create a page where you can check answers to the archived 2016 puzzles without spoiling yourself on the solutions. Until now! If you missed the competition, but would still like to test your mettle on the 2016 puzzles, you can now check your answers on the 2016 Archive Solve page.

19 October 2016
The full guess log for the 2016 competition is now available for download. We've also created a new mailing list for announcements about future competitions.

18 October 2016
The 2016 competition is over! Thanks to all teams who participated, and we hope you enjoyed it. Congratulations to the following prize winners:

We've already begun planning for next year, and hope to see you then! We have set up a feedback form, but also feel free to email us any of your comments on the competition.

Subscribe: RSS news feed. Mailing list.


We are the people who organised the CiSRA Puzzle Competition from 2007 to 2013. CiSRA is not sponsoring the competition any more, but we are still keen puzzle creators and decided to hold a private competition of our own.

Administrative inquiries to the mezzacotta Puzzlers: