Monodoku's Queens-style puzzle guide

A square that cannot work

Imagine placing an animal in a candidate square. If that immediately leaves a row, column or color with no opening, the candidate must be an X.

Try the example

Thinking ahead / 09

Work through the board

A REAL MONODOKU POSITION7 × 7

Outlines show the reason. Rings show the next move.
Small numbers identify matching colors.

Step 1 of 7

Imagine an animal in the square marked ?. This is only a test.

When to use it

Imagine an animal in a candidate square and rule out everything it would exclude. If a row, column or color that still needs an animal is left with no opening, the imagined placement cannot be right. Mark that candidate with an X.

What to watch for

Keep test placements separate from confirmed animals. After finding the contradiction, undo the imagined exclusions and keep only the proven X. A test that does not fail is not automatically a correct placement.

Read the full explanation

Imagine an animal in the square marked ?. This is only a test.
Now column 4 has nowhere for its animal. Every column needs one, so our test cannot work.
That test leads to an impossible board. The square marked ? must be an X.
The Xs are in place. Now look at the remaining openings.
This color has only one square left.
Place an animal in the ringed square.
The monkey belongs in row 5, column 2.

Examples use the game's own hint engine. A test placement is temporary; only the proven move is applied.

The same reasoning applies to other Queens-style games, including Meowdoku, with one animal or queen per row, column and color, and no touching, even diagonally.

You'll learn as you play

No need to memorize it all.

Begin with the basics. Monodoku introduces new techniques with a visual lesson when you need them. Hints explain the reasoning, one step at a time.

Try your first puzzle

Play the full game on your phone