How to Play PetDoku: Queens Puzzle Rules on One 5x5 Board (Easy 42)

PetDoku The JoyPlus Soft Planning Team October 28, 2026

PetDoku is a Queens puzzle. It uses the same three rules as the daily Queens game on LinkedIn and as a one-star Star Battle, with pets in place of crowns. This short guide shows those rules at work on one real board from the game: Easy 42, a 5x5 board with five colors, so five pets.

The three rules

One pet in every row and every column.
One pet in every colored region.
Pets never touch each other, not even diagonally.

That is all. There are no numbers to add up and nothing to guess: every board in the game can be finished by following these three rules. In the game you tap a square once to mark it with X (no pet here) and double-tap or press and hold to place a pet.

Easy 42. Five rows, five columns and five colors: red, orange, yellow, green and teal.

First move: a color with only one square

The red region is a single square in the top-right corner, so the red pet has to go there. The red X marks show everything that pet rules out.

Look at why each X is there. The rest of the top row and the rest of the right-hand column are out because a row and a column hold only one pet. The square diagonally below and to the left is out because pets may not touch. One pet, nine squares gone.

The color rule at work

The orange region has four squares, but three of them are in the top row and already crossed out. Only one is left, so the orange pet goes there.

Every color needs exactly one pet, so when a color is down to one empty square, that square is the answer. Placing the orange pet clears its row, its column and the squares touching it, and the board gets smaller again.

The row rule at work

The third row has only one square without an X, so it gets the next pet. That pet is yellow, so the yellow square in the bottom-left corner is ruled out too.

Rows and columns work the same way as colors: one empty square left means a pet goes there. Now look at the bottom-left X. It is not in the same row or column as the new pet and does not touch it. It is out only because it is yellow, the same color as the pet you just placed.

The last two pets

4. The fourth row has one square left, in green.

5. The bottom row has one square left, in teal.

Solved: one pet in every row, column and color, and no two pets touch.

This board needed only one idea: find a row, column or color with one empty square left. The 6x6 boards that follow need a few more, and the beginner guide walks through them one at a time.

The rules in one minute

Each row, each column and each color gets exactly one pet.
Pets never touch, diagonals included.
After every pet, mark X on its row, its column, its color and the eight squares around it.
When a row, column or color has one empty square left, the pet goes there.

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