How to play Pugduko

Pugduko is a logic puzzle. Every level is a square board split into coloured regions, and your job is to give every region exactly one pup.

The rules

One pup in every colour. A board with seven colours needs seven pups.
One pup in every row and every column. No row or column can hold two.
Pups never touch, not even corner to corner. All eight squares around a pup stay empty.

Every level has exactly one solution, and you can always reach it by thinking. You never have to guess.

Controls

Tap a square to cross it out, as a note that no pup can go there. Tap again to rub it out.
Swipe along a row or column to cross out several squares at once.
Double tap a square to place a pup. On a computer, right-click instead.
A pup on a wrong square costs one of your three hearts and leaves a red cross, so you never pay for the same square twice.

Stars, streaks and the daily

Every level has a par time. Solve it under par for three stars, under twice par for two. Solve at least one level a day to keep your streak burning. Daily Pugduko is a new level every day, the same for everyone, with a single heart and one go only.

Five tricks that solve every level

In the pictures: a dark ring marks the squares the trick is about, a red cross is a square the trick rules out, and a green ring is where the pup must go.

1. The last spot

When a colour, a row or a column has only one open square left, its pup goes there. Cross out everything you can, then look for the last spot.

2. A colour in one line

If every open square of a colour lies in the same row, that colour's pup is in that row, so every other square of the row is out. The same goes for columns.

3. The squeeze

Picture a pup on a square. If it would touch or line up with every open square of some colour, that colour would have nowhere left, so the square is out.

4. Two colours, two rows

Two colours that only fit in the same two rows fill both rows between them. Every other square in those two rows is out. It works for three colours in three rows, and for columns.

5. Try it in your head

Still stuck? Find a colour with two open squares. Imagine a pup on one and cross out what it rules out. If that leaves a row, column or colour with no room, the pup is on the other square.

Getting better

Start each level with the smallest colours: a colour with two or three squares is where tricks 2 and 3 bite first. Cross out generously, because every cross makes the next step easier to see. When you are stuck on a big board, go back to trick 1 and scan every row, column and colour for a last open square before reaching for trick 5.

Play in the browser