15 Puzzle

紹介 15 Puzzle

The 15 Puzzle (also known as the sliding puzzle) is a classic brain teaser. Slide 15 numbered tiles around a 4×4 grid to arrange them in order from 1 to 15. Simple concept, surprisingly challenging! A timeless puzzle game free online.

History of 15 Puzzle

The 15 Puzzle was invented by Noyes Chapman, a postmaster in Canastota, New York, around 1874, though it was popularized and sometimes erroneously attributed to puzzle legend Sam Loyd. The puzzle created a worldwide craze in the 1880s comparable to the Rubik's Cube mania a century later. Mathematicians quickly became interested in the puzzle, and in 1879, two professors independently proved that exactly half of all starting positions are unsolvable. The 15 Puzzle holds a special place in the history of mathematics and combinatorial game theory, and its sliding-tile mechanic has influenced countless puzzle games from Sokoban to modern mobile apps.

15 Puzzle Tips & Strategies

• 💡Solve the puzzle row by row from top to bottom; get the first row correct before moving to the second.
• 💡When placing the last two tiles of a row, maneuver them into a corner position together before sliding them into place simultaneously.
• 💡For the last two rows, solve them column by column from left to right using a circular rotation technique.
• 💡Avoid moving already-placed tiles; if you must displace them temporarily, have a clear plan to restore their positions.
• 💡Count your moves and try to beat your personal record; experts can solve the puzzle in under 30 moves.

Fun Facts About 15 Puzzle

• ★In 1880, dentist Charles Pevey offered a $25 reward (equivalent to over $700 today) for anyone who could solve a specific "impossible" configuration, knowing it was mathematically unsolvable.
• ★The 15 Puzzle was the world's first puzzle craze, with newspapers reporting that it disrupted businesses and legislatures as people became obsessed.
• ★Mathematically, exactly half of the 20,922,789,888,000 possible arrangements of the 15 Puzzle are solvable.
• ★The optimal solution for the hardest solvable 15 Puzzle configuration requires exactly 80 moves.

遊び方 15 Puzzle

1. 1Click or tap a tile adjacent to the empty space to slide it
2. 2Arrange all tiles in numerical order from 1 to 15
3. 3The empty space should end up in the bottom-right corner
4. 4Try to solve it in as few moves as possible!

よくある質問： 15 Puzzle