Xumph
(Published on 25. September 2026, 12:28 by Jorava)
My attempt at beginner-friendly X-Sums. I chose that constraint specifically because I think it's one of the hardest common variants for a beginner to grasp.
Another submission for "The Foundations of Sudoku" (YouTube link) where the idea is to create beginner-friendly puzzles using only 1-2 basic variants.
Rules:
Normal Sudoku rules apply. Place the digits 1-9 in each row, column and marked 3x3 region without repetition.
X-Sums: A number outside the grid gives the sum of the first N digits in that row or column, where N is the digit in the cell closest to the given clue.
The 5 clue in the top left corner is already filled out for demonstration.
Solution code: Row 6
Comments
on 29. September 2026, 00:16 by Jorava
@HereBeNames Thanks, this aligns with how I approached the setting of this puzzle. I wanted to leave a beginner an option to skip some of the bigger daunting numbers and focus on sudoku, or focus on the clues and mostly skip the sudoku. Either way, they learn how X-Sums work and get the satisfaction of finishing the puzzle.
on 26. September 2026, 12:22 by HereBeNames
Nice and an easy puzzle. The difficulty rating on this site is skewed anyways. I disagree with the previous comment stating that unused clues could be optimized.
Having redundant clues makes a puzzle easier. So it's absolutely fine for puzzle that's supposed to be easy to have redundant clues.
And changing that is not an optimization, just a change.
on 26. September 2026, 07:00 by raaaaa
A large number of clues are not used, which can be optimized.
