About Futoshiki Puzzle

Futoshiki is a Japanese logic puzzle whose name means "not equal." It combines Latin square constraints, where no number repeats in any row or column, with greater-than and less-than inequality signs placed between adjacent cells. The puzzle gained international recognition after being published in The Guardian newspaper since 2006. Many players find Futoshiki harder than Sudoku because the inequality constraints add an extra layer of deductive reasoning on top of standard elimination logic. PlayBrain offers three grid sizes (4x4, 5x5, 6x6) with multiple difficulty levels, giving you a smooth progression from approachable introductions to deeply challenging puzzles.

How to Play

1. Fill each row and column with numbers 1 through N (where N matches the grid size) with no repeats.
2. Respect the inequality signs between cells. The open end of the sign always points to the larger number.
3. Start with cells that have the most constraints to narrow your options quickly.
4. Use logic and elimination to deduce each placement. No guessing should be necessary on a well-formed puzzle.