Klotski

How to play Klotski

• Klotski is a sliding block puzzle. Slide the blocks around the box and bring the big red block down to the exit. You win when the big block reaches the middle of the bottom row, right above the exit.
• Blocks can’t be lifted. They only slide up, down, left or right into empty spaces.
• Drag (swipe) a block the way you want it to go. You can also tap a block: it moves one space toward the side you tapped (a block that can only move one way moves that way wherever you tap).
• Keep sliding the same block and it still counts as one move, however far it goes and even if it turns a corner.
• The daily puzzle is the same for everyone, with a new one every day. It’s shortest on Mondays (Japan time) and gets longer through the week. Your streak of days in a row is saved too.
• Stuck? Tap “Hint” to play the next move of a shortest solution from where you are and see how many moves are left.
• On a computer, pick a block with the Tab key and move it with the arrow keys. Ctrl+Z undoes a move. If you close the page, your puzzle is saved so you can pick up where you left off.

Puzzles and fewest moves

Play the classic layout, 40 more puzzles from easy to expert, and a new daily puzzle. In each level, puzzles 1–5 and 6–10 each start easier and get longer. The fewest moves for every puzzle was checked by a computer search of every possible move. Solve one in the fewest moves and you’re an expert.

How to solve the classic Klotski

The 81 moves look long, but every shortest solution follows the same four stages. Aim for the shape at the end of each stage:

1. Moves 1–21: move the wide block from under the big block to the bottom-left corner.
2. Moves 22–48: bring the big block down to the middle rows.
3. Moves 49–67: raise the tall blocks and move the big block to the left.
4. Moves 68–81: bring the wide block up above the big block, then slide the big block out.

• Aim for the finished shape. At the end, the four tall blocks fill the top two rows with the wide block just below them. Getting the wide block from below the big block to above it is the heart of the puzzle.
• Don’t push the big block straight down. Even in the 81-move solution it moves 9 times, and 6 of those moves are sideways. Stepping it aside opens a path for the other blocks.
• Line up the two empty spaces. There are only two. Side by side or one above the other, they let a wide block, a tall block or the big block pass.
• Keep the small blocks together. Parked in a corner or along the top, they leave room for the big blocks to move.
• Go back when you’re going in circles. Undo to the end of the last stage you reached, or tap “Hint” for the next move of a shortest solution.

Why 81 moves?

The fewest moves depends on how you count a move. For the classic layout, a computer search of every position gives:

The well-known 81 uses the first count, and so does this game. From the classic start, the blocks can reach 25,955 different positions (counting blocks of the same shape as identical).

About Klotski

Klotski is a classic sliding block puzzle on a 4×5 board. Its name comes from the Polish word klocki, “wooden blocks.” In China the same puzzle is called Huarong Dao, where the big block is the general Cao Cao escaping through Huarong Pass, and in Japan it is Hakoiri Musume, “the daughter in the box,” where the big block is a daughter and the others are family members and servants keeping her inside. The classic layout you can play here is the best-known starting position of both.