A New Type of Sudoku

On Waverly, one of my most idiosyncratic wave is Puzzles by Humans. It allowed me to discover a hidden world of creative puzzlers. Amongst them, I found a growing group fueling what is now being known as the golden age of sudoku. These so-called setters are inventing countless sudoku variants that can be mixed and matched to create puzzles which force solvers to come up with original deductions.

Leading the popularization of that new puzzling form is the excellent YouTube channel Cracking the Cryptic. It led me onto the (very difficult to navigate) German puzzle portal Logic Masters, which seems to be the birthplace of every new sudoku variant.

Some of these new types of puzzle rely on arithmetics, which I’m not a fan of because it requires solvers to memorize frequent sums. This feels like memorizing frequent definitions in crossword puzzles, which is not what I enjoy in problem solving.

However, there are some new clever variants that dont require you to memorize anything, just to put on your logician hat and prove some theorems. I couldn’t sit idly by the sidelines so… I invented one new such variant! Behold the…

Ant Sudoku

  • Standard sudoku rules apply.
    Digits can’t repeat on lines, columns or 3×3 regions.
  • An ant starts on each of the shaded cells.
  • Each ant must be able to reach at least one of the circled cells with the same letter.
  • Ants must not be able to reach any other circled cell.
  • An ant can move from a cell to an orthogonally adjacent cell if its digit is less or equal to the current digit plus 1.
    Ex: An ant on 4 can move to an orthogonally adjacent 5, 3, 2, or 1 but not to a 6, 7, 8 or 9.

You can play this puzzle online either on F-Puzzles or Penpa+. If you want you can also download a PDF version and print it.


If you get stuck here are some hints, just rot13 decode them:

  • Svaq pryyf fbzr bs gur nagf zhfg nofbyhgryl tb guebhtu.
  • Pna gjb cnguf rire gbhpu gurzfryirf?
  • Znxr fher lbh qba’g fgrc ba gur gbc sbhe.


Here’s the solution, don’t hesitate to give me feedback on Facebook or Twitter.