Takuzu
Takuzu is a logic puzzle on a square grid in which every cell holds one of two symbols; here they are a solid disc and a ring. Fill the grid so that no three equal symbols sit next to each other in a line, every row and column holds as many discs as rings, and no two rows or columns are the same.
How to play
Every Takuzu here has exactly one solution and can be solved by logic alone. Its level is the hardest technique it needs, from spotting pairs at Easy to following a short “what if” until a rule breaks at Expert.
- No more than two equal symbols next to each other in any row or column.
- Each row and each column holds the same number of discs and rings.
- No two rows are identical, and no two columns are identical.
- The given symbols cannot be changed.
Playing on this site
- Tap a cell to place a disc, tap again for a ring, and once more to clear it.
- Drag across cells to paint the same symbol along the way; the whole drag is one undo step.
- With a keyboard, use the arrow keys to move and Space to cycle the symbol.
- Hint points out mistakes first, then names the next technique and highlights where it applies.
- Your puzzle is saved in this browser, so you can come back to it later.
Techniques by level
Every technique the solver knows, from easiest to hardest. A puzzle's level is the hardest one it needs.
Easy
- Pair
- Two alike side by side: the cells at both ends must be the other shape, or three would match.
- Sandwich
- Two alike with one gap between them: the gap must be the other shape.
- Half and half
- This line already has half of one shape, so every open cell takes the other.
Medium
- Line logic
- Every way to finish this line without three alike and with half of each agrees on the marked cells.
Hard
- No twin lines
- One way to finish this line would copy a finished line, which is not allowed. The remaining ways agree on the marked cells.
Expert
- Contradiction
- Assume the opposite in the marked cell and a rule breaks a few steps later. So it can only be this.
Questions
What is the easiest way to start a Takuzu?
Look for two equal symbols side by side: the cells at both ends must hold the other symbol. Then look for two equal symbols with one gap between them: the gap must be the other symbol.
Will I ever have to guess?
No. Every puzzle has exactly one solution that logic alone reaches, at every level.
Is Takuzu free to play here?
Yes. Every level is free, with no account and no sign-in.