Logic Masters Deutschland e.V.

For the 2025 Secret Satan (like Secret Santa for people on the naughty list) I was tasked with providing a puzzle for Nordy.

There is a short example puzzle here.

Shade some cells and fill all unshaded cells with a digit from 1-9.

All unshaded cells form one contiguous region.

No digit may repeat within a row or column.

Digits may not repeat within a cage which must sum to the total shown in the top left, if given. There can be no more than one shaded cells in any cage.

Clues outside the grid give the sums of connected groups of digits in the row/column in order.

A ? may represent any digit from 0-9 except 6.

No number may begin with 0.

A * symbol may be replaced by any number of ?s separated by any number of gaps (including none in each case). Inequality symbols between clues show that one clue is less than the other (a < b means that a is less than b).

For any row/column either all or no clues are given.

An unshaded cells with a circle counts the number of shaded cells in the 3x3 region centred on that cell.

A shaded cell with a circle may only be orthogonally adjacent to other shaded cells or odd digits.

An unshaded cells with a diamond counts the number of unshaded cells in the 3x3 region centred on that cell.

A shaded cell with a diamond may only be orthogonally adjacent to other shaded cells or even digits. Happy solving! Here you can solve the puzzle online:

Solve on Sven’s SudokuPad