Keen Puzzle Online

Keen is one of the classic one-player logic games in Simon Tatham's Portable Puzzle Collection. Complete the latin square in accordance with the arithmetic clues.

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Preparing the game board and controls.

Game Objective

Use the digit range shown by the grid size: a 4x4 puzzle uses 1 to 4, a 5x5 puzzle uses 1 to 5, and so on. Every row and every column must use each digit exactly once, and each thick-outlined cage must satisfy its arithmetic clue, such as making a target total or product.

Complete the latin square in accordance with the arithmetic clues.

How to Play

Click a square and type a digit to enter it. Press Backspace, Space, or 0 to clear the selected square. Right-click a square and type digits to add or remove pencil marks for possible values.

These puzzles reward careful deduction more than speed. Start with the most constrained clues, eliminate impossible choices step by step, and avoid guessing unless the puzzle specifically calls for it.

Beginner Tips

  • First identify the grid size. In a 4x4 puzzle, each row and column must contain 1, 2, 3, and 4 exactly once.
  • Start with small cages or cages whose arithmetic clue has very few possible combinations.
  • A number must satisfy both rules at once: it must fit the cage calculation and must not repeat in its row or column.

Official Rules

For the full original rules, examples, and advanced options, read Simon Tatham's official manual.

Read the official manual

Frequently Asked Questions