The Enigma Rotor Scale

Last Updated: 18 Aug 2016
Introducing our new scale for measuring the difficulty of puzzles.


Colour-coded scale indicating puzzle difficulty
©GCHQ 2016

Our maths magicians love to share their brain teasers to help others learn to love maths too. 

Their puzzles come in various levels of difficulty, you don’t always need to be a genius to solve them.  The Enigma Rotor Scale of Difficulty will give you a guide to what you are up against.  

  1. Very easy. Should be quickly solvable. 
  2. Not too hard but not immediately obvious. You probably need to make a cup of tea for this one. Coffee works too. 
  3. Getting a bit hard now. Tea drinking will help, but a bit of pacing around the room is probably in order as well. 
  4. Something of a meaty challenge and probably one you might need to collaborate with other people to solve. 
  5. Very difficult and time consuming. There might well be multiple answers. But, then again, maybe there’s just one answer. 
  6. At this level it might be far from obvious even what the question is asking, never mind how you might go about solving it.  Good luck!