Sudoku variant · rules and tips

Palindrome Line

A palindrome line reads the same in both directions. The first cell matches the last, the second matches the second from last, and so on inwards. A line with excellent posture and no sense of direction.

Get it onGoogle PlayPlay Palindrome Line on the web
Professor Cryptic, the owl who teaches in the app
Professor Cryptic explains the rule

The Professor's tips

How do you solve Palindrome Line?

01 / Warm up

Start on a 4 by 4 grid

  • On a three-cell palindrome the first and third cells are equal and the middle is free, so you have two values to find, not three.
  • A mirrored pair is an equation. Solve either cell and you have solved its partner without lifting a finger.
  • Think of a palindrome as shrinking the puzzle. Each mirrored pair is one unknown wearing two coats.
02 / Level up

Then try a 6 by 6 grid

  • On a four-cell palindrome the first cell matches the fourth and the second matches the third. Place one digit and its partner is known immediately.
  • When mirrored cells fall in different boxes you gain information across the grid for nothing. A digit settled here is settled there too.
  • An odd-length palindrome has a middle cell with no partner. The palindrome rule leaves it alone, though the ordinary rules still apply.
  • Mirrored cells can never share a row, a column or a box. They must hold the same digit, the ordinary rules forbid a repeat, and such a line could not be solved at all.

The rule, drawn

What does Palindrome Line look like?

  1. Palindrome Line rule illustration, step 1 of 2
  2. Palindrome Line rule illustration, step 2 of 2

Start with a single square

Where can you play Palindrome Line?

Palindrome Line is one of the 17 variants in Cryptic, each with a lesson and unlimited puzzles.

Get it onGoogle PlayPlay on the web