Rune Sudoku

Rune Sudoku is a number puzzle. You fill a 9×9 grid so every row, every column, and every 3×3 box holds the digits 1 through 9 — each one exactly once. Some cells are filled in to start. Easy gives you 45 starting clues, medium gives 35, and hard gives just 25. Every puzzle has exactly one correct answer. You never have to guess.

The game has helpful tools built in. Pencil marks let you jot down possible digits in any cell. Live error highlighting shows you when something is wrong before it causes bigger problems. The grid looks clean and works on both desktop and touch screens. A timer starts when you make your first entry, so you can track how fast you solve each puzzle.

The three difficulty levels are genuinely different. Easy can be solved by scanning rows, columns, and boxes for missing numbers. Medium needs pencil marks and careful elimination. Hard calls for advanced tricks like naked pairs, pointing pairs, and box-line reduction. The rune-themed look fits the EchoForge style without changing how the puzzle works.

Sudoku comes from a puzzle called Number Place, made by Howard Garns and published in Dell Magazines in 1979. Garns was a retired architect from Indiana. He submitted it as one of many puzzles for Dell, and it sat quietly in American puzzle magazines for years.

The name Sudoku comes from a Japanese phrase meaning 'numbers must remain single.' The Japanese publisher Nikoli coined the name in 1984 and introduced the puzzle to Japan. Nikoli also added the rule that starting clues must be placed symmetrically. Sudoku became very popular in Japan through the 1980s and 1990s. Then in 2004, a retired New Zealand judge named Wayne Gould wrote software to generate puzzles. He pitched them to The Times of London. Newspapers across the UK, US, and beyond picked it up fast. By 2005, Sudoku was one of the biggest puzzle formats in the world.

Rune Sudoku follows the rules Nikoli set. It generates a fresh unique puzzle every time instead of recycling a fixed set.