Sniffdoku

Dog sudoku with no numbers: place one dog in every row, column and colour region, and never let two dogs touch. Over 10,000 logic puzzles with a Dalmatian who sniffs out hints.

Sniffdoku is dog sudoku with no numbers: a calm, clever logic puzzle starring a Dalmatian with a very good nose. Place one dog in every row, every column and every colour region. There's just one more rule: dogs never touch, not even at the corners. Every puzzle has exactly one answer, and you can always find it by logic alone.

Over 10,000 levels take you from quick 4x4 warm-ups to big 10x10 brain teasers, then on into endless puzzles. Stuck? Sniff a hint: your Dalmatian sniffs out the next logical step and shows why it works. Place a dog in the wrong spot and the game shows which rule it breaks before a heart goes. Undo any move, mark cells with X, and turn on colour-blind help for a letter and a pattern in every region.

How to play Sniffdoku

One dog per row and per column, and one dog per colour region.

Dogs never touch, not even diagonally.

Tap (or click) a cell to mark it with an X. Double-tap (double-click) to place a dog. Swipe (drag) to cross out many cells at once.

Keyboard: arrows move, Space = X, Enter = dog, Z = undo, H = hint, Esc = levels.

A wrong dog costs one of your 3 hearts; X marks never do.