Klotski Tips: Moving the Big Block in Fewer Moves

Updated September 2026

Klotski is one of the oldest sliding-block puzzles, known in China as Huarong Road. On a 4×5 board you must slide a large 2×2 block down to the exit at the bottom centre, working the smaller blocks out of its way. Solving it once is satisfying. Solving it in a low number of moves is the real game on ujem, since your move count is your score and lower is better. This guide explains how to think about the board so both happen.

Watch the two empty spaces, not the blocks

There are exactly two empty cells on the board, and every move is a block sliding into them. That means the real 'pieces' you are steering are the gaps. Experienced players think in terms of where the gaps need to be next: under the big block, beside a tall block, or together as a 1×2 hole that lets a wide block slip through.

When the two gaps are next to each other, a 1×2 block can move through them in one slide, and so can the big block if the gaps line up with its edge. When the gaps are apart, only single squares can move freely. A lot of wasted moves come from separating the gaps when you needed them together.

Know what each block type can do

The small single squares are the most flexible pieces on the board. They are your tools for shuffling gaps around, and they can slip into corners that nothing else can reach. The tall 1×2 blocks move up and down easily but need two stacked gaps to move sideways. The wide 1×2 block is the opposite: it slides left and right easily but needs a horizontal pair of gaps to move up or down. The 2×2 block needs a full two-cell gap along one edge to move at all.

Keeping this in mind stops you from trying moves that can never work, and helps you see which small piece to move first to open the right-shaped hole.

Clear a lane below the big block

The big block starts at the top centre and has to travel down three rows. Everything in the two middle columns below it is in the way. The early part of a good solution is about relocating those blocks to the side columns, usually by parking the tall blocks along the left and right edges and bringing the small squares up above them.

Once the two central columns below the big block are empty, the block can drop a row at a time. The final stage is usually the trickiest part: the wide block and the small squares need to rotate around the big block so it can take its last step into the exit.

Cut the move count

Each slide counts as one move, even if the block travels two cells. You can often save moves by letting a block slide as far as it can in one go rather than stopping halfway and then continuing. If a small square needs to reach the far side of the board, see if there is a route where it slides two cells at once.

Another common source of extra moves is back-and-forth shuffling: moving a square right and then left again because you changed your mind. Before each move, ask whether it brings a gap closer to where it needs to be. If it does not, look for a different piece.

Learn the solution in stages

Because the starting layout is the same every time, your second and third attempts benefit hugely from your first. Break the solution into milestones: the big block has moved down one row, the big block is halfway, the big block is at the exit. Remember roughly what the board looked like at each milestone, then try to reach it in fewer moves next time.

Tap New to reset whenever a run goes off track. There is no penalty for starting over, only for the moves you make on the way to the exit.

A practical plan

1. Before moving, find the two gaps and decide where you need them next.
2. Move the small squares first to reshape the gaps into the form the next big move needs.
3. Park the tall blocks on the side columns to open a lane under the big block.
4. Let blocks slide as far as possible in one move and avoid undoing your own moves.
5. Reset and repeat, aiming to reach each milestone in fewer moves than last time.

Klotski feels impossible at first and then suddenly logical. Once you see the board as two moving gaps rather than ten stubborn blocks, your first solution will come, and every run after that is about trimming moves.