Futoshiki
A Latin-square logic puzzle where numbers 1 to 5 must obey the greater-than and less-than signs.
Controls
Tap a cell and choose a number 1 to 5; tap the selected cell again to toggle notes mode.
How to Play
Futoshiki is a Japanese number puzzle played on a small square grid, usually 5x5. Place the numbers 1 to 5 so that each number appears exactly once in every row and every column, the way a Latin square works. That much resembles a mini sudoku, but there is no 3x3 box and one extra ingredient changes everything.
Between some cells sit inequality signs, the greater-than and less-than symbols. Your solution must respect them: wherever a sign points, the smaller number has to be on the narrow side and the larger on the open side. Combine the no-repeat rule with those constraints to narrow each cell to a single value. Because it is a different puzzle from classic sudoku, lean on the inequalities as much as the rows and columns.
Tips & Tricks
- Use the signs at the extremes first: a cell forced below a 2 must be 1, and above a 4 must be 5.
- Combine row, column and inequality clues together to corner a cell into one value.
- Turn on notes mode to pencil in the candidates a cell could still take.
Frequently Asked Questions
How does Futoshiki differ from sudoku?
It uses the numbers 1 to 5 with no 3x3 boxes, and adds greater-than and less-than signs between cells that your answer must satisfy. That inequality rule is the key difference.
What do the signs between cells mean?
They show which of two neighbouring numbers is larger. The open side of the sign faces the greater number and the point faces the smaller one.
Is there always one solution?
Yes. Each generated puzzle is guaranteed to have a single unique solution, so careful logic will always get you there without guessing.
