Broken Sign Blog
#167: Polish Puzzle Championship 2025 — Dominoes
13 June 2025I made some puzzles for the Polish Puzzle Championship again, which took place last weekend. This year I contributed one complete round, and a couple of extra puzzles for a mixed round that I will share on Puzzle Square.
As usual, you can find PDFs for all rounds of the championship on the Sfinks website. Please check out the other rounds as well.
I realised last year that I really love domino variants, so I made an entire round of them. As with last year’s Superposition round, I tried to cover the five main genre categories. I also wanted to pick classics as the base genres, so the learning curve of an all-variants round would be offset by familiarity with the core rules. Like last year’s Guide Arrow round, I wanted to do two puzzles in each genre, but this time I didn’t try to make one easy and one hard. I figured this would just create too big of a gap in point values in each pair, where weak solvers would just have to skip all the big pointers and stronger solvers who can’t quite finish rounds would be best off skipping the small puzzles. I was hoping that there would naturally be some variation in difficulty which worked out well.
Instead, I settled on some theming constraints throughout the round. So each puzzle only has clues that come in pairs (it’s a domino round after all), and one puzzle has equal values in each pair and the other has unequal values.
Rules: Place lights into some empty cells so that every cell is illuminated. Each light covers two adjacent cells and illuminates the these cells as well as all cells seen in a straight line horizontally or vertically, not obstructed by a black cell. Lights may not illuminate each other. Clues represent the number of lights in the (up to) four cells surrounding the clue.
Rules: Shade some dominoes so that no two shaded dominoes are orthogonally adjacent and draw a non-intersecting loop through the centres of all the remaining empty cells. Clues cannot be shaded, and represent the number of shaded dominoes that can be seen in a straight line in the indicated direction, partially or totally.
Rules: Shade some dominoes of cells so that no two shaded dominoes are orthogonally adjacent and the remaining unshaded cells form one orthogonally connected area. Clues cannot be shaded, and represent the total number of unshaded cells that can be seen in a straight line vertically or horizontally, including itself.
Rules: Shade some dominoes of cells such that no two dominoes share an edge. Divide all unshaded cells into regions of five orthogonally connected cells so that no two regions of the same shape share an edge, counting rotations and reflections as the same. Clued cells must belong to a region with the pentomino shape associated with that letter.
(For answer check, draw borders around each domino.)
Rules: Shade some dominoes of cells such that no two dominoes share an edge. Place a number from the range given outside the grid into each unshaded cell so that no number is repeated in any row or column. Numbers outside the grid indicate the sums of the numbers in groups of consecutive numbered cells in the corresponding row or column, in order. Sums must be separated by at least one shaded cell.
