How to play Klotski
Klotski is a sliding block puzzle on a small board, 4 cells wide and 5 cells tall. The blocks come in four shapes: one big square, tall blocks, wide blocks and small single squares. Together they fill the board except for two empty cells. Your job is to slide the blocks around until the big one reaches the gap in the frame at the bottom centre, where it slides out.
There is no luck and no timer. Each level is a fixed position with a proven shortest solution, and the game shows that number next to your move count. Solve the level at all and you move on. Solve it close to the fewest moves and you earn three stars.
Moving the blocks
On a phone, drag a block with your finger. It follows you one cell at a time, and if the way ahead is blocked it tries to turn, so you can steer a small block round a corner in one go. With a mouse it works the same way.
If dragging is fiddly, tap a block to pick it and then tap an empty cell. The block slides there by the shortest route, as long as it can get there without moving anything else. On a keyboard, tap or tab to a block and use the arrow keys.
Moves are counted the way puzzle books and solvers count them. One block sliding, however far it goes and even round a corner, is one move. If you move the same block twice in a row, that is still one move, so you are never punished for dragging in small steps.
The classic start
One level in the list is the famous layout most people picture when they hear “Klotski” or “Huarong Road”. The big block sits at the top centre, four tall blocks stand on either side of it, one wide block lies across the middle, and four small blocks wait near the bottom. The fewest moves it can be solved in is 81, which our solver confirms by checking every position the blocks can reach. It is always unlocked, so you can try it straight away, but it is a long puzzle and the levels before it are a good warm-up.
How the levels work
There are 50 levels, ordered from easiest to hardest. The first dozen need fewer than 20 moves and teach you how the shapes fit together. After that the boards use different mixes of blocks, so you meet layouts with more wide blocks, more small ones, or a big block that starts in a corner. The hardest level needs 138 moves.
Levels unlock one at a time as you solve them, and the level panel shows your stars for each one. Your progress and best move counts are saved in this browser, so you can stop and pick up later.
A simple way to think about it
Most beginners chase the big block around the board. Better players watch the empty cells instead. The two empty cells are the only thing that really moves: every block you slide is just the empty space travelling somewhere else. Ask where the empty cells need to be for the big block to take its next step, then walk them there.
Here is a typical pattern. The big block wants to go down, but a wide block lies right under it. Slide the small blocks out of the row below the wide block so there is room, drop the wide block down a row, and now the two empty cells sit under the big block. One move later it has gone down.
When you get stuck, use a hint. It shows the next move of a shortest solution from your current position, with an outline where the block should end up. Following a few hints is a good way to see how strong solvers think, and it never costs you stars.
Other puzzles to try
If you like moving pieces into place, try the sliding puzzle, the classic 15 puzzle with numbered tiles. For planning many moves ahead, the Tower of Hanoi is a good match, and peg solitaire is another old wooden puzzle that rewards thinking a few steps ahead.
How to play Klotski
- The board is 4 cells wide and 5 cells tall. It holds one big 2×2 block, tall 1×2 blocks, wide 2×1 blocks and small 1×1 blocks, with two empty cells.
- Slide a block into empty space. Blocks never jump over each other, turn around or leave the board.
- Get the big block to the bottom centre of the board, over the gap in the frame. It slides out and the level is solved.
- Drag a block with your finger or the mouse. It follows you one cell at a time and can turn a corner in the same drag. You can also tap a block and use the arrow keys, or tap a block and then an empty cell to send it there.
- Moves are counted the standard way: one block sliding, however far and round however many corners, is one move. Moving the same block again straight away still counts as that one move.
- Every level shows the fewest moves possible. Finish at or within a few moves of it for three stars.
- Hint lights up the next move of a shortest solution from where you are now. Undo takes back your last move and Restart sets the level up again.
Klotski tips
Move the small blocks to make room
The small 1×1 blocks are the only pieces that fit through a one-cell gap, so they do most of the work. When the board feels jammed, look for a small block you can tuck into a corner or behind a tall block. Each one you park out of the way opens a path for something bigger.
Think in pairs
Two small blocks side by side take the same space as one wide block, and two stacked take the space of a tall block. The two empty cells work the same way: keep them together and a tall or wide block can always slide into them. Split them up and only small blocks can move.
The big block needs a 2-wide gap
The big block moves only when both cells beside it on one side are empty. Before you move anything, decide which two cells the big block needs next, then work out which blocks have to leave them. Planning one big-block step at a time is much easier than staring at the whole board.
Use the fewest-moves number
Each level tells you the fewest moves it can be solved in. If you are far past it, you have probably shuffled blocks back and forth. Undo to the last position that felt good, or ask for a hint and compare its move with the one you were about to make.
Frequently asked questions
What is the minimum number of moves in klotski?
The classic Huarong Road start needs at least 81 moves, when one block sliding any distance, even round a corner, counts as one move. That is the standard counting and the one used here, and our solver confirms the 81 by searching every position the puzzle can reach. If only straight slides count as one move the minimum is 90, and if every one-cell step counts it is 116.
Where does klotski come from?
Nobody knows for sure. Sliding block puzzles with one big block to free were sold in Europe and the United States in the early 1900s, and the same puzzle is known in China as Huarong Dao (Huarong Road) and in Japan as Hakoiri Musume, the daughter in the box. The name Klotski is usually linked to the Polish word klocki, meaning wooden blocks. Claims that the puzzle is centuries old are not backed by good evidence.
Why is it called Huarong Road?
The Chinese name comes from the novel Romance of the Three Kingdoms. After his defeat at Red Cliffs, the warlord Cao Cao escapes along the Huarong road, where the general Guan Yu lets him pass. In the puzzle the big block is Cao Cao, the other blocks are the generals and soldiers blocking his way, and the gap at the bottom is his way out.
Is every level solvable?
Yes. Every level was chosen by a program that searched all the positions the blocks can reach, and each one is stored with its proven fewest number of moves. The levels run from 3 moves to 138 moves, easiest first, and the classic start sits in the middle at 81.
Is klotski the same as the 15 puzzle?
They are cousins. In the 15 puzzle every tile is the same size and you put numbers in order. In Klotski the blocks come in four sizes and only one block matters: the big one has to reach the exit. Mixed sizes make Klotski feel very different, because a big block can be stuck even when there is plenty of empty space.
