How to Play Futoshiki

What is Futoshiki?

Futoshiki is a Japanese logic puzzle played on a square grid. The goal is to fill every cell with numbers so that each row and column contains each number exactly once, while respecting the inequality signs between cells.

Rules

• Fill each cell with a number from 1 to N (where N is the grid size).
• Each number must appear exactly once in every row.
• Each number must appear exactly once in every column.
• Inequality signs (< and >) between cells must be satisfied.
• Some cells come pre-filled and cannot be changed.

Controls

• Click/tap a cell to select it.
• Number keys (1-6) or the on-screen number pad to enter a number.
• Arrow keys to move between cells.
• Delete/Backspace to clear a cell.

Difficulty Levels

• Easy (4x4) — More given numbers and fewer constraints. Great for beginners.
• Medium (5x5) — Balanced challenge with moderate constraints.
• Hard (6x6) — Fewer givens, more constraints. Requires advanced logic.

Tips

• Start by looking at cells with the most constraints.
• Use elimination: if a row already has certain numbers, the remaining cells are narrowed down.
• Chain inequalities: if A < B < C in a 4x4 grid, A can only be 1 or 2.
• Use the Undo button if you make a mistake.