# Pawdoku: free dog logic puzzle By the I Love Pariah Dogs team. Last updated 2026-09-27. Play it at https://ilovepariahdogs.com/play/pawdoku/ ## Pawdoku in short Pawdoku is a free browser logic puzzle. You place one dog in every row, column and coloured region of a grid, and no two dogs may touch, even at a corner. There are 1,000 levels, from 4×4 to 10×10, and every one has exactly one solution that you can find by logic alone. ## The rules 1. **One dog in every row.** Each row gets one dog, no more. Drop a second dog into the same row and both go red until you move one. 2. **One dog in every column.** Same idea, running top to bottom. One dog per column. 3. **One dog in every colour.** The coloured blocks with thick borders are regions. Each region needs exactly one dog, even if it snakes across half the board. 4. **No dogs touching at the corners.** Two dogs can't sit diagonally next to each other. Dogs side by side or stacked would already share a row or column, so corners are the only touching left to rule out. That last rule is what boils each board down to one answer. ## Controls | Action | Mouse or touch | Keyboard | |-|-|-| | Mark a cross | Click an empty cell once | X | | Place a dog | Double-click an empty cell | Space or Enter | | Clear a cell | Click a cell with a cross or a dog | Either key on a filled cell | | Move around | Point at a cell | Arrow keys | ## Strategy ### 1. Start with the small regions A region with a single cell is a free dog, so place it. A region whose cells all sit in one row or column is a good clue too: its dog is somewhere on that line, so cross out the rest of the line. ### 2. Cross out what each dog rules out Every time you place a dog, cross out the rest of its row, column and region, plus the four cells at its corners. It's a bit tedious, but it means the empty cells left are the only ones that could still hold a dog. ### 3. Spot regions stuck in one row or column If every cell of a region sits in a single row, its dog has to be in that row. That row is now taken, so cross out every cell in it that belongs to another region. Columns work the same way. ### 4. Count regions against rows Say two regions sit entirely inside the same two rows. Those two dogs use up both rows, so nothing else can go there. It works for three regions in three rows too, and for columns. This is the trick that cracks the big boards. ### 5. Try a "what if" When you're down to two options, imagine a dog on one of them and follow what happens. If some region ends up with nowhere to put its dog, that option is impossible, so cross it out. Since every level has exactly one answer, a wrong guess always hits a wall. ## Worked example: level 6 Rows count from the top and columns from the left. 1. **The teal region is stuck in one row.** Teal is just two cells, and both are in row 2. Its dog has to be in that row, so cross out the rest of row 2. 2. **Two regions, two columns.** The green block only covers columns 2 and 3, and so does teal. Two regions, two columns: those columns are spoken for. Cross out every other cell in columns 2 and 3. 3. **Pink is left with column 1.** After those crosses, every free pink cell is in column 1. Pink owns that column now, so cross out the last cell of it, at the bottom left. 4. **Blue has to use the bottom row.** Look along the bottom row. Only its last two cells are still free, and both are blue. So the blue dog is in the bottom row, and the other blue cells can go. 5. **Try a "what if" on orange.** Orange has three cells left: two in the top row and one at the far right of row 3. Try a dog on either top-row cell and follow it through. Both roads end in a corner touch somewhere among teal, green and pink, so cross those two cells out and orange is left with row 3, column 5. The rest falls into place. Blue takes the bottom row at column 4, green goes in row 4 at column 2, teal sits in row 2 at column 3, and pink takes the top-left corner. Five dogs, one per row, column and colour. ## Pawdoku by the numbers Before colours are added, a 4×4 grid has 2 ways to place four dogs so that none share a row or column or touch at a corner. The count is 14 on 5×5, 90 on 6×6 and 4,79,306 on 10×10 (Hertzsprung's problem, https://oeis.org/A002464). The coloured regions pin each board down to exactly one of those layouts, and all 1,000 levels were checked to have a single solution. ## Levels, stars, hints and score | Grid | Levels | Dog layouts before colours | Hints per level | Time for 3 stars | |-|-|-|-|-| | 4×4 | 1–5 | 2 | 2 | 32s | | 5×5 | 6–20 | 14 | 2 | 50s | | 6×6 | 21–50 | 90 | 3 | 1m 12s | | 7×7 | 51–150 | 646 | 3 | 1m 38s | | 8×8 | 151–350 | 5,242 | 4 | 2m 08s | | 9×9 | 351–650 | 47,622 | 4 | 2m 42s | | 10×10 | 651–1000 | 4,79,306 | 5 | 3m 20s | Three stars for beating the time in the table, two within 2.5 times that, one after that. Each star is worth 100 points and each hint costs 25, so the top score is 3,00,000. Replaying a cleared level only adds points if you beat your previous best for it. Levels unlock one at a time. ## Glossary - **Region:** A group of touching cells of one colour, outlined with a thick border. Every region holds exactly one dog. - **Cross:** A × you place on a cell to remember that no dog can go there. It is a note, not a move, so crosses never count against you. - **Locked region:** A region whose cells all lie in one row or column. Its dog must be on that line, which rules out the rest of the line for other regions. - **Corner touch:** Two dogs on diagonally neighbouring cells. It is the only kind of touching Pawdoku forbids, because side-by-side dogs already share a row or column. - **Layout:** One way of placing the dogs so that no two share a row or column or touch at a corner, ignoring colours. The coloured regions leave exactly one layout standing. ## Questions ### Is Pawdoku free to play? Yes. It's free on I Love Pariah Dogs, with no account and nothing to download. ### How many levels are there? 1,000, from 4×4 up to 10×10. You unlock them one at a time by clearing the one before. ### Is Pawdoku like Sudoku? It's a cousin. Both are solved by ruling cells out until only one fits, but Pawdoku has no numbers. You place one dog per row, column and coloured region, so the thinking is pure elimination. ### What is a Queens-style puzzle? A grid puzzle where you place one marker in every row, column and coloured region, with no two touching. Pawdoku is one, and it's a cousin of the classic eight queens puzzle. ### How do I solve Pawdoku? Start with the smallest regions, cross out everything each dog rules out, and look for regions stuck in one row or column. The strategy section and the worked example on this page walk through it. ### Does every level have only one solution? Yes. Every board was checked to have exactly one solution, so logic alone will get you there. ### Is my progress saved? It's saved in your browser: the levels you've cleared, your score and the board you're on. Close the tab and pick it up later. If you clear your browser data or press the bin button, you start again at level 1. ### How do I place a dog? Double-click an empty cell, or press Space or Enter with the cell selected. A single click puts down a cross instead. ### Why did my dogs turn red? Two dogs are breaking a rule: they share a row, column or region, or they touch at a corner. Clear one of them and the red goes away. ### Do hints cost anything? Each hint takes 25 points off that level, and each level only allows a few. Your stars depend only on how fast you finish. ### Is there sound? There's background music and a few small sound effects, but everything starts muted. The speaker button above the board turns it on.